Plants

[Sylvia Bernstein]

what do you have the most success growing?  what specific varieties to you recommend?  what should be avoided, in your opinion

[John Cubit]

The seeds are going right into the grow bed indoors.  No brown spot, they take off with in days but the stem is as thin as thread and literally the 2 little leaves on them seem too heavy. The peroxide I have is for dental use.

TCLynx said:

Where are you starting the seeds?  is the system indoors?  I'm not sure but the problem with the lettuce sounds a bit like damping off.  Does it look like a little spot on the stem just above the gravel line is pinched and rotting and the plant falls over?  That would be damping off and is a disease that is common starting seedlings indoors.  I've heard that you can brew some chamomile tea and cool it off and put in a spray bottle and mist the seed starting area and small seedlings with it daily to prevent the problem.  I've never done it though.

I don't think soaking lettuce seeds in hydrogen peroxide is likely to help much and wet lettuce seed is likely to be difficult to handle.  AS to 15% and 50%??????  those % both sound like industrial use levels and I would probably not want to handle either of them.  For Soaking seeds I'm pretty sure you need something well less than 3% unless you are just doing a quick dunk before you plant.

[TCLynx]

you might dilute down to like a 1% spray and use the H2O2 to spray the lettuce seedlings as soon as you see them appear.

Be careful not to get too much H2O2 into the system since it can kill the beneficial bacteria too.

And brighter light might be needed, really spindly stretching reaching seedlings are often a sign of not enough light.  But it seems odd that some of the other plants are doing better?

[Ian Cameron]

I've had my 75gal, 12sq ft media beds in operation for a year come Jan 1. 8 feeder goldfish and 15 creek minnows. I use 25watt  64k grow flourescents ganged in fours. So far I've managed 5 crops of swiss chard, radishes and lettuce. What I found is the light distance from the seedlings is critical. Basically my lights are hooked to a pulley system that allows infinite adjustments. I allow no more than 4" above the plant tops. This seems to keep the stems strong and straight.  I think that plants will reach for light, and they will grow stems to do this, at the expense of the leaves . BTW, I'm getting close to 90% germination with the direct seeding so I know I'm doing something right.

Keep experimenting, you will find the sweet spot, that is what I find so intriguing about this thing called aquaponics.

[John Cubit]

I will look at the lighting.  Currently it is just a Philips 120-Watt BR40 Agro Flood Plant Light Bulb.  It is odd that all the other plants are doing fine.  The one issue I did have earlier on was the tomatoes were getting sunburn.  I let new growth come from the base and cut the rest off and it has been fine since.

TCLynx said:

you might dilute down to like a 1% spray and use the H2O2 to spray the lettuce seedlings as soon as you see them appear.

Be careful not to get too much H2O2 into the system since it can kill the beneficial bacteria too.

And brighter light might be needed, really spindly stretching reaching seedlings are often a sign of not enough light.  But it seems odd that some of the other plants are doing better?

[Ian Cameron]

One other thing, what is your light timing, mine are on for 16 hrs off for 8. I tried 18 on 6 off, to mimic where I used to live just north of 60 but it seemed to make little difference. I also have hung aluminum foil curtains from the light reflectors down below the edges of the media tanks. I'm sure this helps in dispersing the light more evenly.

[John Cubit]

Light is on from 6am to 9pm, and is 32 inches above bed.  Manufacturer recommend not closer than 12" due to heat.

Here are a few pictures to get an idea.

That is the lettuce

Snow Peas

The only light

Both Grow beds, North facing window..no good light there