I recently started another hydro grow in my tent. Here are the details>>
2.5 x 2.5ft tent.
2ft 8 T5 LED (used when plants are small). Then move to a 315W LEC
2 bucket DWC system. One for grow and the other for "maintenance". 6 gallons total liquid volume.
Nutrient chiller. Nutes kept at 68 DegF.
Two air pumps and 4 air stones. 2 stones in each bucket.
I have plenty of circulation and plenty of bubbles. I've done this before with great success.
Here's the deal. I started the system up about three weeks ago. At first I just ran 100% tap water through the system. I let this run for a few days. I then topped of the rez with tap water, adjusted the pH to 6.5, then added General Hydroponics "Maxi" series nutes. I've never used this product before. I have always used the GH Flora series and never had any trouble.
So then after a couple days I was checking the pH (was 6.1) of the solution and I noticed a bubbly foam on top of the solution. That, plus a smell that I've never had in my reservoir. It was a swampy smell. It smelled something like a sewer. Well obviously that is bad.
I drained the entire system of the solution, then I refilled with tap water. I added about 1/4-1/2 cup of bleach. I used a sponge to wipe down every surface that I could get to with the bleach solution. I let the bleach run through the pumps and through the nutrient chiller for over and hour. Slowly, I rinsed away all of the bleach solution. I 'think' I cleaned it really well. I used to "brew"... not that that makes be an expert.
I refiled the reservoir, adjusted pH 6.0, and added nutes. Little more than four days later, the smell is back.... and so is the foam.
I revisited the smell. It doesn't really have a "rotten" smell. It has a swampy nose to it for sure, but it smells more like compost than.... @ss.
So for know I'll let it run for a while to see what happens. The seedling I have in the system doesn't have significant roots yet, so it isn't in contact with the nutes. I can move it anytime.... for now.
Interested in any comments.