Backyard Aquaponics
A place to discuss aquaponics

I built a indoor system back in May using constant flood. The Grow Media is Leca the tank a 20 gallon with tillapia all about 2-3" 15 in all. There is a wide spectrum led grow light.

My issue is that seeds sprout, grow spindaly to about 3" tall and then die. Nitrates are around 160ppm due to seaweed extract.


IAny one know or have a idea what the issue is?

That sounds like lack of light. My indoor system often does almost exactly the same thing, but I'm only using one set of flouro grow lights, and the plants turn towards the window when the sun shines in.

I'm guessing they are cheap LED's... with LED's you certainly get what you pay for.

I have some experience with LED's and many of the cheap ones aren't even suitable for raising seedlings, but the better quality, recognised brands are fine for raising leafy greens and veggies, they are expensive though. In the US the HydroGrow LED's have proven to be very effective.

Doubt your nitrates are at 160 due to seaweed extract (unless you are using the wrong sort).

Spindly sounds like not enough light and death may be due to that or damping off.

No, not Cheap LEDs, I can't remember the exact brand but I purposely avoided cheap brands.

Also, what is Damping?

get the light closer to the plants.. within a couple inches

Seriously a couple of inches?

Also looked it up on amazon purchase history. It is a Appalo LED.

Sorry if I'm being noobish. My prior systems have all been outdoor systems.

Due to the angle of the reflectors used in horticultural LED's they will be ineffective if you run them 2" from the plants, you will have areas of intense, concentrated light and areas of very little light. They should be run at a height that allows the light footprint from each LED to overlap the light footprint of the one next to it by 50%

Iv only got the 1 LED light, its a 80 watt I believe. There are also a pair of bulbs, 1 red and 1 blue but they are just normal incandescent bulbs.

The spindly, leggy plants are caused by lack of light. Apollo is supposed to be a good brand of light... To be candid, I believe the saying about getting what you pay for with led lights is outdated. I bought the inexpensive Taotronics lights, and have had great results. Once "economies of scale" make their way into something, price plummets. Look at TVs. OLED TVs are already cost competitive with LCDs. As far as the damping off, citric acid may help. It can be found in the supplement section of your favorite health food store, and cheese making shops. I sprinkle it on the soil when I am starting seedlings. ( I start most of my seeds in soil, then transplant into my system) the other thing that may help is a fan. Air circulation not only keeps the moisture manageable, but the movement on the plants encourages healthy growth.

To be candid... No it's not!... and there have been multiple examples on here and other forums of people purchasing cheap LED's and having very dismal results.

I don't sell LED's anymore, but quite a few of my customers have purchased them elsewhere, online primarily, and everything from cheap no-name brands on ebay etc, to expensive brands widely recommended on grower forums etc... and the over whelming majority that have purchased the cheaper versions... have got exactly what they paid for.

Manufacturers purchase LED's by "bin" grade. Testing for grade is done on each individual LED at the time of manufacture and is primarily to do with light intensity and wavelength, they get sorted into a number of different bins depending on their performance. The cheaper manufacturers purchase lower bin grade LED's, that's how they manage to make their LED arrays so cheap. Many don't even purchase LED's with plant specific wavelengths, they use simply red & blue, but not of the correct wavelengths. If you have a look at the LED's in the top shelf brands, while there's mainly red and blue (of the correct wavelengths), there's also pink, purple, orange, yellow, green, white etc... and even some that look as though they aren't working, because the wavelength can't be seen by the human eye... plants need more than just red and blue light.

The ones I bought give very specific wavelengths. They were inexpensive, and the results have been fantastic.

Ya. I got this specific light and its currently about 2.5-3 feet above the GB, which is a 55 gallon rubber made water trough.....with a total area about twice what this lights meant for As for the Citric acid, i'm sure my local kitchen cuboid has some, but just how much should I put into the system? there is around 30-40 gallons of water in the whole system and the turn over is i would imagine about 5-6 times a hour if not more. Circulation shouldn't really be much of a issue, the front door is only 15 feet away and the hallway tunnels the air right past it when we go out on average of 4-5 times a hour.