I recently took at an attempt at growing some vegetables inside under LED lighting with hydroponics. I am using General Hydroponics nutrients with 1 tspn per gallon which comes out to about 400 PPM (suggested nutrient levels according to GH). I been growing mainly tomatoes and cucumbers. So far, it's been about close to two weeks since I moved the plants to the hydroponics system. I been flooding it daily once for about 5 minutes, just enough to touch the bottom of the pots and then drain (the water touches the bottom of the rockwool for about a minute or so before it drains out, could this be the problem?). Everything was going well until this morning. A few of the plants, mainly the mature ones are slumped over (see the attached image). My PH level is right about 6.0. Lights are on 16 hours a day. I also have oxygen bubbling about 30 minutes prior to the flooding everyday. What am I doing wrong? Not enough nutrients? Too much water? My PPM level has maintained it's levels throughout this whole process.
Any help would be greatly appreciated. I have a ton of these plants that I'm afraid that I'm going to lose :(
agreed with GG, Although plants do only basically use red, and blue light for their daily functions, absolutely nothing beats sunlight, and there is something about a florescent lights qualities that plants pick up on better than LED's
Agree with above: Confirm the PAR rating of the lights.
Do you have a filter over the intake of the pump or somewhere in the system? Is it plugging up? If so, this suggests the fertilizer may not be fully dissolved.
Lift a few containers and see if they are still clean under the water line and knock a few plants out of their pots. Is the substrate clean? With the wrong flood/drain cycle it is possible for sludge to build up and choke the roots. The roots then do not get the oxygen they need and fungi can take over, and the plants wilt.
Your plant look pretty young (too short a time) for this to have happened, though.
Are you raising the lights as the plants grow? Is it too hot right next to the lights?
Next question is how many watts of LEDs are you using. LEDs look very bright when you look into them because they are very localized light source. A 3 watt LED may look very bright, but it isn't going to grow a Tomato very big.