NRG,
I don't have power for a chiller..well..I could but that would mean sacrificing light and until a chiller will help me more than all that light...well, I've been getting away with it.
My flower room hovers at about 87deg lights on and probably hits below 68 lights off. That isn't great. My light temps are a bit high and that's a big difference in temps..day to night.
My "water" temps though don't hit much over 70. Some "tricks" are to use pipe insulation on your drains and feeds, using coolers for tubs/buckets is a great idea that I don't do, obviously keep your res in a cooler room, if your rooms have concrete floors hey are a great heatsink, as was mentioned use a big res-try to keep the majority of the water volume in the res in the cool room by using tubs/buckets/coolers that aren't TOO big and use drainlines/pipe that isn't too big.
If you do the math, there's quite a bit of volume in 1-1/2" or 2" pipe and it can heat up fast. I'm still messing with pipe size. Originally I was running 5gal pails each with dual 3/4" bottom drains. I was worried about root clogging (which didnt happen) so went up to 20 gal tubs and 1-1/2" drains. That made my water temps rise to unsafe numbers. Now I'm using about10gal tubs with 1-1/2" drains but the drains reduce to 1-1/4" and go into 1-1/4" return to res pipe. This gives me more volume in the cool res room and less in the hot flower room. It also allows me to keep the larger drains in the tubs. NEXT time I might reduce those 1-1/2" drains to meet 1" return pipe. We'll see.
PEACE
