iceman_1000000
Well I have a few questions.

1. What is the humidity?
2. You say the temp is 68, is that the water or air temp?
3. You say the ppm is 600. How does that relate to the full strength of the nutrient you are using (is 600 ppm full strength?)?
4. If your only watering once every 6 hours in an aeroponic system, I'm surprised the plants are doing do well.
5. You say you are using T12's. How many? For how many plants (coverage area)?
6. Do you know what that 175 ppm of your water supply (well water) consists of? Also are you using a UV light to kill soil born pathogens and/or any micro organisms?

Hi homehydro,

Hopefully I don't miss anything.

1. I currently don't have a way to measure the humidity but if anything I think it would be on the dry side.
2. Air temp and water temp are both about 68.
3. Overall ppm is 600 ppm after it has been added to the 175 ppm well water. The fertilizer is 16-4-16 with 16% nitrogen. They have only been in the system for a couple of weeks so they haven't had their solution changed yet since starting. Maybe I have some bacteria in there? I thought about changing the solution out or possibly adding h2o2 but to be honest I wasn't really sure what would be the best thing to try.
4. Yeah I'm actually surprised the water seems to be enough. All the plants look perky and generally healthy. What should I be looking for to tell if they need more water?
5. I have 1 4' t12 fixture with 2 bulbs in it putting out about 6000 lumens combined just a few inches above the plants. The area is probably 2 feet by 5 feet. Basically the lettuce are in two rows spaced about 10 inches apart directly below the fixture. I have 2 rows sharing a fixture and I'm just getting ready to add another fixture so each row would then get their own fixture.
6. No uv light to kill anything, and I'm not doing organic. Also I haven't had a full analysis done on the water yet. Only a basic one to test that it is safe for consumption.

Sorry hope I answered all your questions. If I missed anything let me know.

Also for what its worth I also have basil started in the system and though it is still small (just starting a second set of leaves) I don't see any browning yet.

Thanks again!

Watering every 6 hours is a LONG time for aeroponic! I'd check the temperature below the lights and make sure you're not heating them up too much. Humidity is a little low for lettuce, but I'd lean toward old fashioned heat problems from the pic and what you mentioned.

Let me know what you find?