And that makes perfect sense. So, in short, the problem is the same (no oxygen to the roots), but the cause is different.
Sog is doing something cool (pun intended) in his grow room, and it led me to a cheap alternative... run the water out of the res, into a mini-fridge that's outside the room/tent (this is my cheap-o contribution), through some wound up copper pipe, then back out to the res. If you can't put the fridge outside the grow room, you can just put it near the out fan to pull out the heat generated by the fridge.
Here's the coils he made:
https://www.rollitup.org/grow-journals/131873-sog-grow-room-op-6.html
This place is great for learning from other people's mistakes... thanks for showing me the importance of keeping the res temps down. +rep
ya i have checked out his thread, its pretty cool.. however if i remember correctly he is using the water through the coils as an air heat exchange, not running his res nutes through it..
see the problem is that copper will degrade in an acidic solution like used for hydroponic applications.. the copper will get into the res over time and WILL build up and kill all of your plants from poisoning.
even when used in more alkaline solutions like aquariums it can degrade and get into the tank and kill the fish..
a stainless steel, or platinum tube would work, but would cost much more, is harder to bend to shape, and not as readily available.
and mrduke, if you do not have fresh air coming into your room, then you are limiting your plants growth and doing them a disservice.. if you can afford it, i would go for it.. extra co2 is never a bad thing..
if you are going to do co2, do it right, get a tank, regulator, timer, and most importantly a controller! if you dont, you will not be able to control the amount effectively, and will waste the co2, and could end up injecting too much and cause some problems.
the sentinel one is like 450 bux, and worth every penny.. if you do not get a controller, then save up the money to do it right, and in the mean time add an active intake