OK, so I am growing in soil right now in a 4 x 8 tent. And really wanting to try a simple DWC set up in 4 separate 17 or 27 gallon black totes.
Figuring out how I’ll keep the water cool enough.
Since I’ve read that the water needs to be kept under 70 my tent is usually 80° or a little over…
I have a 4’ x 8’ table here that is 2’ tall. I used to park a four wheeler on top of in the shop. Plenty strong…
I’m thinking about putting the tent on top of that and cutting holes in the floor of the table and the tent, for the totes to hang suspended completely below the floor of the tent.
The tent is in a room with a tall enough ceiling, that can be kept at 68 degrees. With fans blowing underneath the table onto the totes
Think it’ll work? Overkill?.. Useless?..
If I knew anybody to tag, I would…
Cut out styrofoam sheets to fit around your tote, creating a separate space. That alone is good for about 5F. Then if you used the bottom intake and exhaust ports on tent (if you have them) to run cool air across bottom of tote. Frankly I would suggest you bite the bullet and buy a chiller. Really. It’s a ‘One and Done’.
I usually can keep my flower room temps st 76 or a couple of degrees Fahrenheit cooler…
Don’t usually worry about my water temps unless room temps go over 78 degrees Fahrenheit…
I also use frozen 2 liter bottles if necessary to keep water temps down… 
To me, making your system not as simple seems like better option than cutting holes in floor. Make it recirculating system and keep larger res outside of space. If you need to, you can always prep frozen water bottles to drop into main reservoir.
Buy a chiller. Much easier and than all the makeshift methods you can try that just wont do what you need.
Well I’ve read that with my quantum board LEDs that 84 degrees is the optimal temperature for maximum transportation and nutrient uptake.
That depends on RH: a VPD chart will tell you. IMO 84F is a bit too warm and something more like 78F as ideal.
When your not using a chillier and your running a rdwc , 76 to 78 degrees Fahrenheit is ideal for room temps , but with room temps at that level my canopy temps run about 76 to 80 degrees Fahrenheit and that’s just what works best for me…
Humidity runs from 25% to 45% depending on outside temps and humidity…
I run a open system with outside temps running 128 degrees Fahrenheit down to 23 degrees Fahrenheit…
That’s when I limit outside air intake and use my ac for cooling my lighting and replacing my inside air and supplementing co2 if necessary…
When my outside temps are below 80 degrees Fahrenheit , my room almost runs for free…
My flower room was built just for that purpose…
To be a flower room… 
I was NEVER successful with frozen bottles. I have 3 systems in flower room, and EACH one has a 1/4hp chiller. Personally, I wouldn’t try hydro without one. That’s just me. @peachfuzz is the King. He might be able to pull it off, but I lost 4 runs to root rot trying to get by without a chiller. If you get a chiller, make sure it’s for salt water. That way, your nutrients wont hurt it
Can I ask what chiller you use?
I use eco plus hydro chiller.
Back in the day i made a swamp chiller out of a chwap ac unit. It worked great for years, was for beer tho not bud. If your interested and pretty handy i can explain how.
Cant have copper it gets ruined fast. Good chillers for hydro or salt water are made of titanium.
If we were staying in this house I would have done this: just outside the East wall of my garage is a dirt strip between my house and the next (about 6 feet) and is shaded perpetually. I considered digging a 6 foot deep hole with an acoustic posthole digger and bury 50 feet of small diameter plastic tubing then backfill. Run to a pump with a stainless steel heat exchanger coil in the circuit and pump distilled water with a bit of methanol (for nothing to grow in the liquid). I’ll bet I could get a consistent 60F from that.