Backyard Aquaponics
A place to discuss aquaponics

Hi All,

Has anyone had any experience growing tomatoes indoors under grow lights?
As an experiment i bought a 150watt LED grow light. I put it in a well ventilated dark spot in the garage.

I set the lights about 12" off the top = and noticed that the bottom leaves always yellowed and the top ones seem to behave really weird - they turned purple and seemed to curl/twist upside down.

Any suggestions?


Here's the light system

http://www.ebay.com.au/itm/280980984176?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Heres the tent

http://www.ebay.com.au/itm/330763065576?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

PS: I've tried black russians and beefsteak tomatoes so far no luck

pictures attached, since moved them outside to try and save them

Seems like that light should be OK, 3 watts/bulb should have enough penetration especially for a little shaver like her! What's your light cycle? Temps? Humidity? Those tents are great for intensive, high-performance grows but have to be well-ventilated (internal circulation and exchange) and it only takes one critical growth element to get out of optimum and it seems like it always goes for a record!

Sometimes a drastic change can cause some pretty wonky behavior: from natural or HID to LED for example, or odd light cycles from a timer error. Usually the new growth will be fine. Looks like you're in soil?

Howdy,

Yes experimenting in soil for the moment, and was running about 18hrs on, 6 off.
I had a ventilation fan sucking air out to get some air flow.

Not sure on temps or humidity..

The individual LED's may be 3w each, but if it's a cheap no-name brand then the LED's will most probably be cheap rejects, bin 5 I think they are referred to, because each LED is graded by the manufacturers when tested after manufacture, they are then put into different "bins" depending on their output.

Not only that, the LED's in the vast majority of cheap no-name brand LED arrays are not only rejects, but they are not the correct spectrum. it's not as simple as saying you need 70% Red LED's and 30% Blue LED's etc... the spectrum needs to be spot-on.

I have many customers that have tested a wide variety of different brand LED arrays and there is only one brand any of them have had any success with.

Philosophically I have a bit of a problem with growing crops using only or primarily artificial lighting but I was talking to a researcher the other day that opened my mind to the possibility even if only by a crack.

Plants need mostly red and blue light (of the right wave lengths) for photosynthesis and only tiny bits of the rest of the spectrum if any. Instead of using sunight to grow plants if you capture the suns energy with solar panels (PV or Thermal) and use the electricity to power red and blue leds in the proportion that the plants need them. Even with the inefficiencies of the electricity generation process you apparently still get more photosynthetic light and so can grow more plants per unit of sunlight.

Now it just feels wrong to me and I suspect that the rest of the spectrum has a part to play in plant health, growth and nutrition but if the science stacks up then vertically stacked growing systems could go from ridiculous to standard design and practice.