Hydroponic Questions and News

Wednesday, December 24, 2008

Correct pH for Hydroponics

Hello I was wondering what the correct pH would be for Vegetative and Flowering Tomatoes. Thanks.

 

Hi there

Good Question.

-          In soil, the minerals are less available, and depending on soil types and the type of fertiliser, all plants can have a variety of pH's that plants will do well, or do very badly, at.

-          However in Hydroponics, only the most soluble form of a nutrient component is used. E.g. Phosphoric Acid for Phosphorus is only Phosphorus, and is very available and very soluble being a true liquid. As all the elements are at their best, we can then look at the availability at the ideal.

-          In Hydroponics, nutrients are very available in the range of 6.0 to 7.0 pH, and the best is 6..3pH

-          When mixing a pre-made formula with town water (usually in the range of 7.2-8.0) the agronomist/chemist will design the nutrient to fall within the 6-7pH range.

-          From there it is likely to rise in almost every situation, except in the case of very low light, such as shade or long periods of cloud, and also in some varieties with a heavy demand for potassium during flowering.

-          Generally, people use pH up when they have used too much pH down, and I always question anyone buying pH up to see if they really need it, or need to increase their lighting.

-          In some cases a pH of 5.5-6.0 is recommended for people using an alkaline media such as Rockwool. BE aware of any information relating to pH may be written by those who use Rockwool and translate it to other medias.

-          My preference with Rockwool is to pre-soak slabs in pH below 5.0 and then rinse. I then use a large syringe to suck out moisture from the slab, to test the difference between my pH mixed up, and the pH in the slab itself. This can be applied to a lot of medias, but don't damage the structure or the roots by doing it everyday. Common sense always applies.

Hope that helps

 

Scott

 

Scott Andrew

www.hydrocentre.com.au

www.expressmailorders.com.au

Hydrocentre and Express Mail Orders.

Shop 1 / 27 Lawrence Drive Nerang QLD 4211 Australia

Phone (07) 5527 4155 (Phone is always recommended for urgent problems or dilemmas as email can take several back and forth's to achieve a solution)

scott@hydrocentre.com.au (Recommended for non-urgent items)

email checked morning and afternoon minimum on week days only

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Portions of Growing Questions (i.e. not general correspondence) we receive may be edited and placed into our FAQ portion on the website as part of our free advisory service. Personal details will be completely removed. If you wish not to participate please let us know by return email. We value your Privacy.

 

 

 

Friday, December 19, 2008

Spider mites

hello scott...is there any product to kill spider mites..what would you recommend?

 

Kill-a-mite is the best one

-          3 day withholding period means its relatively safe

-          Kills adults and eggs so no second spray required

-          $25 for 100ml @1ml per litre means its very economical

 

Hope that helps

 

Scott Andrew

www.hydrocentre.com.au

www.expressmailorders.com.au

Hydrocentre and Express Mail Orders.

Shop 1 / 27 Lawrence Drive Nerang QLD 4211 Australia

Phone (07) 5527 4155 (Phone is always recommended for urgent problems or dilemmas as email can take several back and forth's to achieve a solution)

scott@hydrocentre.com.au (Recommended for non-urgent items)

email checked morning and afternoon minimum on week days only

Privacy

Portions of Growing Questions (i.e. not general correspondence) we receive may be edited and placed into our FAQ portion on the website as part of our free advisory service. Personal details will be completely removed. If you wish not to participate please let us know by return email. We value your Privacy.

 

Thursday, December 18, 2008

Temperature for Veggies in Hydroponics

Hi.

Could you please tell me the ideal water temp in reservoir for growing tomatoes. I have it on 24 deg is that ok or a little high

 

Hi there

Best temp is above 18 degrees and below 25.

I usually look for 20-24 degrees over a 24 hour period.

So if its 24 at the hottest in the day, then it should remain above 20 at night…

Depends on the loss rate for your system.

Below 18 nutrients become less available, above 25 dissolved oxygen levels drop away

Hope that helps

 

Scott Andrew

www.hydrocentre.com.au

www.expressmailorders.com.au

Hydrocentre and Express Mail Orders.

Shop 1 / 27 Lawrence Drive Nerang QLD 4211 Australia

Phone (07) 5527 4155 (Phone is always recommended for urgent problems or dilemmas as email can take several back and forth's to achieve a solution)

scott@hydrocentre.com.au (Recommended for non-urgent items)

email checked morning and afternoon minimum on week days only

Privacy

Portions of Growing Questions (i.e. not general correspondence) we receive may be edited and placed into our FAQ portion on the website as part of our free advisory service. Personal details will be completely removed. If you wish not to participate please let us know by return email. We value your Privacy.

Wednesday, February 06, 2008

Using Chlorine in tanks...

Hi, I have root rot , and have not in the past had sufficient info on how to treat it .
Here try this,  $30.00 thank you.  
If it works let us know , if not , try this one at $ 45.00 etc , etc .  
Well I threw in the tank a lid full of pool chlorine,  
with the words  LIVE OR DIE!
after 1 week I drained the tank and refilled etc .
some of the plants that were too bad any way were  thrown  out and the rest are still living  , much to my surprise.
The question is what damage could I do if I was to use the pool chlorine in small doses 
eg 50 grams /  mls etc  on a regular basis in 1000 litres,
desperate to stop this problem or take up needle work ...  and stuff hydroponics .

 

Hi there
 
Chlorine burn is the risk.
chlorine sterilises by removing air from the water, suffocating everything at the bug level.
it also removes air from the roots.
 
If you want to experiment you'll find out how much works and how much just bleaches the roots and hurts the plant.
I'd pick up a chlorine test kit and keep a low level, barely detectable, in the tank.
 
So how this works is the chlorine reacts with the bugs, turns into a gas and is "destroyed"
When there is some "free chlorine" then you have protection.
When its gone so is your protection. 
I'd suggest that you don't rush in and keep the chlorine high, 
so maybe you can wait a day or so and keep it at the lowest level.
If there is "free Chlorine", you know that the chlorine has done its work
and the remaining chlorine is a signal there is no micro organisms, algae, bacteria, anything for it to react to.
 
HOWEVER
Pool Chloride is really not recommended, but its cheap.
It has to be carried around in dangerous goods vehicles and a spill requires a Hazmat team.
It is toxic to all living tissue, but living tissue is resilient enough to survive it in low doses, in short periods.
Putting it in water is the number one cause of Bowel cancer in the western world (showering in or drinking it)
I have a 1 meter high carbon filter on my home water supply to filter two toxic chemicals, Chlorine and fluoride, out of the water.
 
Monochloramine is a safer stable chlorine used for PYTHIUM treatment,
and is available under the brand name PYTHOFF.
We have it in 1 litre $20 and 5Litre $80 and test kits are available for $25
 
Hydrogen peroxide works by oxidising, which ADDS oxygen to the bad guys who burn.
Roots are unaffected at normal doses. Safe for treating drinking water.
Hydroshield is $20 for 1L and $80 for 5L
2ml per litre every 2 days until problems are gone, 2ml per litre per week thereafter.
 
Ozone generators add O3 (oxygen is O2) to the water,
and works just like the Hydrogen peroxide,
$250 a unit and it runs continuously off 240Volt power.
 
That's a basic rundown.
 
Call my staff for better info as you sound like you got crappy advice.
Root rot can be controlled and eliminated.
But we need to talk to get the reasons for the problem,
solve the source of it, treat the condition, and keep it away.

 

Scott Andrew
Nerang Hydroponic Centre
Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia
Phone (07) 5527 4155 (Phone is always recommended for urgent problems or dilemmas as email can take several back and forth's to achieve a solution)
scott@hydrocentre.com.au (Recommended for non-urgent items)
email checked morning and afternoon minimum on week days only
Privacy
Portions of Growing Questions (i.e. not general correspondence) we receive may be edited and placed into our FAQ portion on the website as part of our free advisory service. Personal details will be completely removed. If you wish not to participate please let us know by return email. We value your Privacy.

 

 

 

 

 

Monday, February 04, 2008

130W COMPACT FLUROS

130W COMPACT FLUROS

Hi there Scott just a quick question about the compact fluorescent 130 watt kits.  If you use the three light spectrums can you successfully get a plant to flower as well as with the HPS systems also what area does one lamp and shade do i.e. is it equivalent to a 600 watt light and shade.  I originally only wanted a fluoro system for growing time only but after looking on the net it says you can flower as well and it would be certainly cheaper on power and fuel.  I want to purchase at least one of the CFL kits but need your advice.  Thanks heaps wait to hear from you

Hi there
1. Growers reporting need 1 of these lamps every 30-45cm depending on reflector/reflection
2. if a plant starts under a 14000 or 6000K spectrum, and when its ready to flower use the 2700K spectrum, with the grow spectrum as a side or bottom light, growers report successes with less heat and less ventilation required.
3.May take about 2 weeks longer to finish from start to finish.
4. total coverage around 50-80cm across.
5. Bulb can hang down, so plant can be 30-40cm above, beside and below lamp.
6. I prefer a chinahat reflector, to reflect all upward light down onto the plant, and panda film (White plastic) to reflect the light back from the sides. Plants can be grown up into the reflector, alongside the lamp.
7. For cuttings I prefer to have the lamp horizontal, to spread the light wide. Say 70cm x 50cm would be typical coverage over young plants.
Hope that helps
Scott
Scott Andrew
Nerang Hydroponic Centre
Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia
Phone (07) 5527 4155 (Phone is always recommended for urgent problems or dilemmas as email can take several back and forth's to achieve a solution)
scott@hydrocentre.com.au (Recommended for non-urgent items)
email checked morning and afternoon minimum on week days only
Privacy
Portions of Growing Questions (i.e. not general correspondence) we receive may be edited and placed into our FAQ portion on the website as part of our free advisory service. Personal details will be completely removed. If you wish not to participate please let us know by return email. We value your Privacy.

Monday, October 29, 2007

HPS and MH different lamps

Dear Scott, I am starting out in growing orchards, and some small vegetable plants like lettuce, tomatoes,beens. I have approx 6.5m2 to work with inside my shed 2.5m X 2.5 roughly can you tell me what the difference is between the following 600w pressure sodium bulbs? philips Son-T Plus General electric Luca grow 600w powerplant HPS 600w also I have been told that the 600w Metal halide superveg 600w will provide more leaf and lateral growth? is this correct? is there any way I can find out what PAR or lumens these lights put out? and what height above the plants should I have the lamp? Regards, P 
 
Hello
1. Sunlight is much more suitable than Lighting as its free and brighter, however lighting gives you seasonal control, away from pests.
2. A 600W will cover 1.5m x 1.5m maximum. Lights will not generally penetrate more than 60cm of foliage, so wise use of tying down plants, use of trellis or netting will benefit you.
3. Son T has not got enough blue, burns hotter and less bright. Its not much different to a street light.
4. GE Lucagrow is my preferred lamp, best overall grow and flower spectrum, lower heat output, very bright
5. Metal Halides are a white/blue light spectrum, and generally not necessary, but will provide more leafy growth and encourage more branching. Not as efficient in light output as a HPS lamp.
6. Son T approx 70,000 lumens - much of it in wrong spectrum
7. GE Lucagro 89,000 lumens approx - some of it in wrong spectrum.
8. PAR lighting is a term first coined by Venture lighting USA, and I understand, is heavily weighted towards what THEY think is the best spectrum, based on what levels of sodium, Xenon, etc that they want to put in the tube. Venture makes Agromaster, Sunmaster, and other OEM lamps for store chains. They are cheaper than many for us to buy and the last time I had one running in my store it exploded. I still find bits of glass occasionally. I believe the concept of PAR to be good. Not sure about whether PAR is accurate or not.
9. Heat is the issue. If you consider the reason the lamp is not close to the lamp is due to the heat, you should have the lamp as close to the plants as possible without burning them. Since plants grow well in the same climate you and I feel comfortable, put you hand under the lamp, find the point that would be uncomfortable to you, and keep plants out of that area. If your room is cool, well ventilated, very breezy, humid/dry, bulbs horizontal not vertical, all have an effect. If you keep a fan on the lamp, you can bring the lamp closer, and get say 10-20% more light on the plant. This is the major way a plant gets energy, so more light will directly affect the growth rate of a plant.
10. Try reading the growing guides at www.hydrocentre.com.au/catalogue and a lot of questions may be answered.
 
Have a good day
 
Scott
Scott Andrew
Nerang Hydroponic Centre
Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia
Phone (07) 5527 4155 (Phone is always recommended for urgent problems or dilemmas as email can take several back and forth's to achieve a solution)
scott@hydrocentre.com.au (Recommended for non-urgent items)
email checked morning and afternoon minimum on week days only
Privacy
Portions of Growing Questions (i.e. not general correspondence) we receive may be edited and placed into our FAQ portion on the website as part of our free advisory service. Personal details will be completely removed. If you wish not to participate please let us know by return email. We value your Privacy. 
 
     

Monday, July 30, 2007

commercial hydroponics business in West Africa

Scott, a wonderful site with so much information. This is part of my problem as there is so much information and advice out there I am not sure in which direction to go. I am thinking of establishing a commercial hydroponics business in West Africa. We live in the captial city situated on the Atalntic Coast. We have 2 acres of land in a hillside village. As you would expect temperatures and humidity remain high throughout the year. The mean temp is about 27- 30+ C and relative humidity averaging 80% -90% +in the rainy season and 50% in the dry season. There are two distinct seasons.A dry season from Novemeber to April with sunshine hrs  

Suggest covered crop in greenhouse, using a water culture system (plants float on rafts above a air bubbling solution). Use concrete blocks to make a pond, plastic line it or plastic paint it, and fill with nutrients with irrigation pumping aerated solution up to bubble around roots lifting the roots into the top 10cm of the solution where there is a lot of dissolved oxygen.

 averaging 6-8 hrs and a ( very!)wet season. the heaviest precipitation is from July to September with rainfall averaging annually 430 -580mm and with 2-4 average sunshine in this season. the area is an area where vegetables are grown and is at an elevation of about 350 metres. There is some moderation of humidity and temp as a consequence. But not much. The first thing to note is that there is no permanent supply of electiricty where the land is although this may change over time. This  

Maybe get wind power or solar to supplement the generators

   means in the short term we shall be dependent upon generators. We plan to grow the typical range of vegetables such as tomoatoes, cumcumbers, peppers, beans and would like to grow both onions and potatoes for which there is a large mkt and which is largely dependent upon imports.There may also be a possibility of nich mkts for herbs for export, flowers for events. My initialfeeling is that an ebb and flow system or an ebb and flow deep pod system would be most appropiate  

Ebb and flow might work on some crops.

Tomatoes cucumbers peppers beans are all ok - potatoes need 50cm or more in depth of media, not viable hydroponic farming, onions 20cm deep minimum, and both root crops subject to a lot of rot, so not good for filling with water...

 as we would be looking to keep costs down and would need a fall back position should there be mechnical problems with the generator. That is why I am not in  

The floats would be ok for a while, its what we use a lot of in Asia where there are high temps and humidity. Once water becomes stagnant, root rot can begin to become a problem, so it lasts for a while. Media systems could be watered by hand or by gravity as an alternative. Suggest coconut coir or some form of sawdust (some are poisonous) coal ash, gravel (doesn't hold water well) as medias in grow bags or plastic pots, irrigated by pump/gravity drippers.

 favour of NTF although ihave one seasons esperience with this system many yaers ago. what do you think about this asthe most appropriate system? Could we develop a system which is dependent or partly dependent upon solar? do you have any thoughts on this? Having reviewed growing media I am leaning towards a mixture of perlite and vermiculite.  

Is it cheap enough?

 However i am also conscious of the need to keep roots cool to avoid bolting and wonder whehter E&F is the most appropriate system to combat this. I read somehere that the most cost effective way of dealing with this is to put a frozen bottle in the tank each day!! I am looking to keep costs down and to use local  

Don't put anything frozen in the tank it will precipitate nutrients. Use a fountain and a fan to cool the water by evaporation, or some sort of waterfall...

 material where ever possible. i am not sure who I could contact to discuss this. I need to design acost efective system but when you apply the simply calculation of dividing total advertised costs for most systems by the number of plants to be grown you soon find out that many systems are exorbitant vv anticipated output. I  

Absolutely.

 have recently been looking at a hydrostacking system which looks very intensive but this appears to use a drip system which I am not sure is the most appropriate in a situation where power is both limited, irregualar and expensive. do you know anything about this? There will I think need to be some form of cover especially in the rainy season. what I am thiinking is that a bamboo structure could be erected with open sides and covered with some type of polythene covering. I am unsure  

Will need rain protection. Clear plastic will tolerate fairly heavy rain, rigid polycarbonate is better if monsoonal rains are predicted, as it will pay for itself in ripped covers...

 whether this would be required during the dry season as this might lead to a build up of heat rather than provide shading. Do you have any thoughts on this?  

Rigid sheeting can be removed. In QLD we use plastic covers above the crop and shade cloth on the sides to prevent insects and wind getting in and tearing the covers/plants.

 Another critcal decison lies in the total area required to make this commercially viable.Clearly we have sufficient land for this but is there a system for calculating projected crop productions? ie what could be theexpected output for tomatoes, peppers, etc using such and such a system covering such and such an area? Based  

Its a black art. Do your sums on how much you can expect from a type of crop and then see if it can be grown. You will need some small test systems to investigate crops needs and costs in your environment. It will come in handy over the years for testing, and 10-30 plants is enough.

 upon this it will be feasible to calculate annual costs vv purchase of equipment, maintenance and replacement costs. Market research would then determine the financiall viability of the proposed business. Coming back to the beginning there is so much advice that it is difficult to know where to start. I know that I need to  

Buy Commercial Hydroponics by John Mason. About $40 plus about $15 postage if you want it from me... Its a very good start and shows you where to cut costs.

 decide upon an approriate system, to identify a way to keep costs down in terms of the system, the materials to be used and selecting the most appropriate supplier. However most suppliers lead you to believe that hydroponics is so sensitve that if such and such a piece of equipment is not purchaced then production will  

Most suppliers need your money. Successful growers become experts and don't need these people. Its not hard to do. Its hard to make money but that's true of all businesses and especially farming. Farmers either are very successful or pitiful failures, and I can't identify where the differences are...

 be radically and adversely affected. I have the feeling that the system is more forgiving than most suppliers and scientists make it out to be. What are your reactions to this? I should add that i have found Growing Edge to be quite helpful and unbiased in their articles and opinions. I am also conscious, as you can see,i have numerous questions (and manymore!!) and that trying to deal with these over the internet is not the most appropriate or satisfactory manner to deal with these. Is there an answer to this?Is it too much to expect that I can enter into a dialogue with someone? I must say that despite all the difficulties I have been feeling quite  

I don't think anyone can give you a heap of time without money becoming an issue.

 optimistic until I hooked up with your commercial link where I note that you inidicate that 95% of commercial businesses fail and that your advise is not to attempt it!! That sort of spoilt my day!! I think in light of the above i have just one question for you Scott and that is ' What would you do and how would go about setting up such an enterprise in the situation described above?' I really do look forward to your response. Rgds and thanks in advance

1. Read all the books - take magazines with a grain of salt...

2. Test system

3. research crop and costs/income on smallest scale first

4 formulate a better plan

5. Try to get another successful grower to work with you, even if they are across the country from you. Pay them something for their time if necessary. They are less likely to try and sell you something you don't need, and point you to where you need to go.

Best of luck

Scott

Scott Andrew
Nerang Hydroponic Centre
Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia
Phone (07) 5527 4155 (Phone is always recommended for urgent problems or dilemmas as email can take several back and forth's to achieve a solution)
scott@hydrocentre.com.au (Recommended for non-urgent items)
email checked morning and afternoon minimum on week days only
Privacy
Portions of Questions received may be placed into our FAQ portion on the website as part of our free advisory service. Personal details will be removed. If you wish not to participate please let us know by return email. We value your Privacy.

 

Tuesday, June 12, 2007

chillies, new leaves & flowers,curling and dry

chillies, new leaves & flowers,curling and dry
09 Jun 2007
Scott hi, having a bit of a problem with my chillies, they grew very well last year with great yields, but this year the new leaves are curling and appear dry, the flower buds also dry and fall off before flowering, i've got them in foam cups full of perlite immersed in Green Yeild solution with similar mix to last year after propogating seeds in jiffy pots and transfering when they are approx 75 mm tall, i drain, flush and refill every 10 to 14 days, hope you can help, another question i had was propogating palms in a similar way to the chillies is it a good method ? as i wanted to grow them to about 300mm tall before planting in garden, thanks regards . 
 
Hi there
 
1. Curling and dry.
a/ Is it too cold?
b/ Could be too strong Nutrients. Tip burn could happen to confirm this.
c/ Over watering/Root rot would show up at slimy black or brown (decaying) roots with yellowing of the oldest/lowest leaves. Make sure there is high oxygen around the roots. Hydroponics is about putting the nutrients in the water, not the roots. The roots should be in air with the lowest amount of nutrient so they can get to the air. Your system seems to have very small containers, lack a lot of root growth area, and probably too much available water/nutrient. Only a guess as I haven't enough information to judge your system, but keep in mind, the less wet the roots are, the healthier the roots will be.
 
2. Flower buds dropping off before flowering
a/ Phosphorus? Phosphorus becomes unavailable below 15 degrees. If the temp is below this for the whole 24 hours, this could be a reason.
b/ Temperature is more important that pH for nutrient availability (i.e. very important)
c/ Any other stress/sickness could create this problem. Often plants will try to flower to save the species before dying. I have encountered people who believed they were getting good crops, when the stress was causing a quick and short flowering/fruiting. Improving the system might yield better.
 
3. Propagating palms.
a/ Perlite in a pot and fill the saucer with nutrient. When its gone, do it again. Keep an eye on the nutrient strength.
b/ Some palms like full strength, some give you tip burn and want half strength.
 
Hope that is a start for your questions. give our website a look and read the hydroponic catalogue on perlite.
 
Have a great day
 
Scott Andrew
Nerang Hydroponic Centre Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia Phone (07) 5527 4155
email checked morning and afternoon minimum on week days only
Privacy
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Thursday, April 12, 2007

Transplanting strawberry runners (Certified runners)

Transplanting strawberry runners (Certified runners)
11 Apr 2007
Should I cut most of the leaves off my transplant before inserting into the hydroponic system using Growool plugs I am using an NFT system, Second question is: how often and for how long should I irrigate the plants? (Far North Coast NSW)
 
I suggest speaking to the strawberry runner association (whoever you bought the runners from) as some varieties can vary.
Growool should be moist not wet all the time.
If not using anything (i.e. put in the channels bare rooted with no Growool) we would use 30min on and 30 mins off until the temperature is above 30 degrees, then continuously until the temperature drops again. Then monitor this and perhaps adjust slightly to perfect healthy root growth. Growool holds water and since strawberries are prone to crown rot, I would irrigate for 15 minutes, and then do it again when the Growool is past moist and on its way to being dry. This will vary with evaporation rates, humidity, temperature, and so on. It also depends on the amount of Growool and how much root mass will be outside the plug, because if the Growool is wet and the roots have exceeded the plug, the external roots may dry out. Management may require that some system where the Growool is irrigated infrequently at first, then by adjusting the flow height, or the position of the plug, the plug might be out of the water stream and more frequent watering can be done with only external roots be wet. These external roots would then "wick" the water up to other roots in the Growool and above the waterline.
Hope that helps. It can be complicated.
Scott
 
Scott Andrew
Nerang Hydroponic Centre Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia Phone (07) 5527 4155
email checked morning and afternoon minimum on week days only
Privacy
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Thursday, March 01, 2007

Intake fan question

I am constructing a grow chamber of 1x1x2.4m containing 1x600W HPS, 250/1000 centrifugal/carbon filter, panda etc...
I need to get a intake fan that will be appropriate for the rest of the set up - it will be mounted in an external wall with a screen to stop bugs and ducted a very short distance (say 30cm) into the base of the grow chamber. What would you recommend?  PS- I know the exhaust/filter combo is ridiculously large for this area

Hi there
Well a small fan is going to over run, so you'd need at least a 250mm inline fan
$190 gets you a 250mm Red Spectrum Fan which will do about 1500 cubic meters per hour.
Customline HGT 25 Axial fan
 
A lesser fan would be a blockage as it wouldn't move fast enough.
Due to the airflow, you might get away with just an open vent, as this is probably better than a small fan getting in the way.
 
I guess the first thing to think is, will it be hot?
If it is hot, then use a fan, if not, try a bit of ducting as a vent and see how you go.
Hope that helped.
Feel free to call the shop to discuss it further.
Scott
 
Scott Andrew
Nerang Hydroponic Centre Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia Phone (07) 5527 4155
email checked morning and afternoon minimum on week days only
Privacy
Portions of Questions received may be placed into our FAQ portion on the website as part of our free advisory service. Personal details will be removed. If you wish not to participate please let us know by return email. We value your Privacy.
 

Saturday, February 10, 2007

Micron Bubbles in DWC System

Micron Bubbles in DWC System

09 Feb 2007
Hi there, I have been searching so much to answer this question but was not successful at finding an answer. I hope you can help me. I am building a bubbler system and was wondering what the best micron size for bubbles is? The smaller the bubbles the better because roots can easier absorb oxygen and nutrients that way correct? In addition, many micron small bubbles create a greater surface area than a few large bubbles and DO should also be higher with smaller bubbles correct? But what micron size of bubbles is best for DWC systems? thank you so much, I hope you can help me!
 
Hi there
 
DWC is when the roots are submerged (to a some extent)
 
1. Bubbles should create a current to lift the water from the bottom to absorb water at the surface.
2. Bubbles should be the main way to break the surface tension as they come to the surface to allow for oxygen absorption
3. Bubbles should lift the roots gently to keep in the roots nearer the surface.
4. The circulation should cause the whole water supply to move and keep oxygen levels high throughout the solution, even at the bottom.
 
As we watch the bubbles they start at the bottom and if they were being absorbed they should disappear. They don't disappear, they actually grow in size until the "pop" at the surface.
 
Bubble size in Deep Water Culture has never been important. If you try small bubble and larger bubbles it is not as important as Water movement to the surface is. Movement of water must be 100% to ensure all water has been aerated and the surface must move to absorb oxygen. So airpumps or water jets must be placed throughout and have large flow rates to ensure speed of turnover. Don't break the roots though...
 
To maximise results - roots should be both in the water and above the water, so build a airspace above the water. The roots in the air will remain damp through the other roots "wicking" the water up by capillary action, and humid air and splashing. These roots will act like Aeroponic plants and provide high performance.
 
Hope this helps

Scott
Scott Andrew
Nerang Hydroponic Centre Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia Phone (07) 5527 4155
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Friday, November 17, 2006

RE: hydroponic light

hey scott,

I was wondering if you could tell me the length of this light? I'm going to be using it on my 6ft aquarium do you think this light would work? and are they metal halide lights?


I assume you mean the 130W high output fluro that we are advertising on our website in our catalogue and at http://www.hydrocentre.com.au/130Wlites/index.htm
The lamps are great for aquariums too as they come in a 14,000K ultra blue for aquariums and a 6000K blue for plant growth in tropical aquariums. These are both the typical colours of Metal Halides. The Flowering spectrum is available but more for veggies and other flowering/fruiting plants.
The lamps are 30cm long, the reflectors we use are 60cm x 43cm and have an effective range of around 80x60cm and would penetrate well about 30-50cm depending on the intensity required.  The reflector, lamp and adaptor is $170 I would suggest that 2 should cover a 6 foot aquarium, but corals might be best at a range of 20-40cm. If you tank is very deep then either raise the coral or go for a 400W Metal Halide. (About the same price but they are hot and will heat the surface of the water.)
 
These 130Watters would be equivalent to a 150W to 250W metal halide, and because they don't run at high temperatures, they don't need large exhaust fans to keep the lights from heating up the water. This heat can lead to having to raise the lights. The 130W runs only nicely warm to the touch , not incendiary hot like a Halide, and is a better idea for most situations. The 130W is fine to touch, but don't leave your hand on it for long though as it is fairly warm.
 
In all cases where lighting is used, effective glass shielding must be in place whenever the light is running or the bulb will break if fish splash water on the lamp. Turn off lights while doing maintenance/feeding.
 
Another idea is to use an existing hood (such as a wooden hood) and add your 130W fluro/s and maybe some UV like Actinic blue 40-60W or similar for a nice effect in the evenings when the main light might be turned off. A simple lampholder with a lamp and adaptor is $130 but maybe some reflective material such as white steel or aluminium can be used to protect the wood from some prolonged warmth from the lamp and to reflect the light into the tank.
 
There are some 100Watt versions available but are not approved for use in Australia. I can get these lamps but the general school of thought is to avoid them altogether.
 
Scott
Scott Andrew
Nerang Hydroponic Centre Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia Phone (07) 5527 4155
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Thursday, November 09, 2006

EC metre with Soil?

EC metre with Soil?
Hi  
I have just borrowed an EC meter from a friend to check my nutes etc, I grow in soil and have real difficulty when plants go into 12/12, the first few weeks are fine but then they start to show deficiences, i suspect they need a good flushing. If i flush them and check the ec of the drain off would this give me a fair indication of the amount of salts in the soil? if so should i be looking to get roughly the same reading from both the water in and the water out? A freind has told me that an EC metre wont really do alot for me using soil, as The organics I use dont contain salts. In the way that Hydroponic fertilisers are eg- he says organics are not made from mineral salts, and that hydroponics are made from Salts?? ps- I grow african violets, and kitchen herbs like basil in Pots. 
 
Hello
I see what you want to achieve. Nutrient testers test the dissolved solids in the solutions. Organic solutions tend to under read, and it is mainly due to insolubilities, and may also be due to organic oils not dissolving and not conducting.
To do a test on a potting mix, we would fill a jar about 1/3 full of soil, and the rest with close to pH neutral water. We shake it vigorously and then allow it to settle, and test the liquid. This is good for pH testing and might be able to yield some results with an EC/CF meter.
I don't think that testing the flow of water from the bottom of pots will help you at all. The speed of the water when you flush, the quantity flowing through and quantity in the test, all will hugely remove any  science from the results.  If an amount of minerals dissolve, and you have them in an unspecific amount of water the EC will change, yet the mineral salts content will not. There would not be any data that is useful here.
 
Anyhow, its a good thought. I highly recommend changing to a good grade of Perlite as a soil substitute and you should increase your blooms and leafy growth if using nutrients. Have a look at the hydroponic guide/catalogue at www.hydrocentre.com.au for more on Perlite.
 
Have a great day
 
Scott
Scott Andrew
Nerang Hydroponic Centre Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia Phone (07) 5527 4155
email checked morning and afternoon minimum on week days only
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Thursday, October 19, 2006

Small Set up

Hey there.
I'm looking to get into hydroponic growing.
Aside from the obvious, I'm also looking at growing some other things indoors such as tomatoes, chillis...etc....nothing too big.
The system I'm looking at getting going on would only be relatively small (not after those stupidly insane "grow rooms" I've seen), lets say at most I'd want to grow 4 things at a time. The unit itself I could take care of, I'd assume a wardrobe or something of the like would be fine given the proper ventilation, yeah?
So...just to start off, I'm not looking at spending a GREAT deal of cash, I understand the lights are most likely the most expensive part of the investment...
So, what lights would I be best to invest in, what would be best to use for ventilation, what material would I be best to grow in, and what kind of nutrients would you suggest for, say...larger fruit?
I mean hey, since you seem to be a store someplace here, I'd be happier to deal with you than some overseas supplier. If you give me good advice, and some suggestions, I'd be happy to look at your stuff...at this point, I'm after suggestions, as I'll be buying in say 2-3 weeks.
So yeah, hit me back when you've got the time, let me know what you think'll be the go in this situation.
 
Hello
Wardrobes can make excellent units. They need to seal well when the doors are closed. This is so they only draw fresh air from the intake fan, and only exhaust through the exhaust fan. Then you can have control.
Work out the cubic capacity of the wardrobe. Then look at fan performance. (maybe look at my catalogue and information pack at www.hydrocentre.com.au) You need to be able to change the air about 20 times per hour in winter (under 20 degrees) about 200 times per hour in summer (over 25 degrees)
The light I prefer is a 400W Son T agro ($185) for the system you are looking at, which is a maximum area of 1m x 1m and mostly, only the top 50-60cm of foliage will get light, the leaves below shaded by the ones above. Try to think of running a net up the back and sides, and train the plants into the netting. This will ensure the light reaches the maximum leaves. You can also train them sideways and even down again if they grow too well and you run out of height in the wardrobe..
Ventilation and light must be as close to ideal. So that means a nice sunny day, not above 30 degrees, not below 15 degrees, somewhere you and I might feel comfortable. If you feel comfortable, the plants will do well. If its stuffy, humid, hot, cold, or otherwise to you, the plants may develop problems.
 
If budget is an issue, I recommend hand watering to start, using Perlite in pots, watering with a good nutrient until moist and the saucer has some nutrient in it. When the saucer is empty, and the pot is getting lighter, then its time to do it again. Flush the pots with fresh water every 2-4 weeks. Nutrients will have a small bearing on yield, but the Carbon Dioxide in the air is the bulk of the plant so ventilation is the key. The light levels determine how much energy the plant has so the light is important. Once these two are maximised, then the other things will work and not before.
 
Nutrients such as Powergro Grow ($22) and Bloom ($22) are great for people who are basic watering type of Hydroponics. Canna is usually is another nutrient ($35) and can give better results, but you need to keep an eye on strengths and pH's, while Powergro will work with most town water supplies without adjustments.
 
Both of these use high grade natural minerals and organic components. Avoid nutrients with synthetic components if its for consumption. Check with me if unsure.
 
We are in Mail Order and try our best to give fast shipping, plain wrapping, and only ask that you give us a chance to help by phone on (07) 5527-4155. Talking allows for a faster question and answer session and we can always tell you the ways and tricks that will suit you if we can get into your situation. I guess the key is helping you through this, so we need to take this one step at a time or it might get a bit confusing.
 
Ok Hope that helps. Let me know if I can clarify more, but look at the catalogues (indoor and hydro ones) and call or email us with your new questions.
 
Thanks for emailing
 
Scott
Scott Andrew
Nerang Hydroponic Centre Shop 17 / 39 Lawrence Drive Nerang QLD 4211 Australia