The first thing to do is add an AIRSTONE and aerate the hell outta the solution. This will add more air into the reservoir and that should help

Secondly, keep adding more/larger frozen 2-liter bottles of water, although this can be a pain, on the super HOT days it will help along with the aeration

Lastly, you can BURY your reservoir in the dirt, this will also prevent heat buildup.

Keep in mind that DARK containers do well to block light, but they also heat up nicely....I also grow in the heat of the summer and have a bunch of extra aeration in my reservoir and so far so good, even on the hot 100 degree days

Here is a link that might be useful: http://www.TechnologyGarden.net

Thanks for info.

I don't think areation could be the problem though. I found the system I copied. The username was vipvermon and I copied his snaking pipe system, pictures further down: http://forums.gardenweb.com/forums/load/hydro/msg0315495420684.html?29

The water goes through this think like a small water rapids and drains back into the solution bucket like Niagra Falls. I think it areates itself pretty effectively.

However, I will see if I can either bury or put some insulation around my 5 gallon solution bucket. I painted the corrugated pipe white to reflect the heat and the solution bucket is already white. The only thing black is the hose that lifts the solution up to the beginning of the pipe. Maybe I should spray paint that hose white too. Hard to believe though the short time the solution moves through that it could heat up that much.

Does anyone have a cheap refrigeration system for their solution? Any ideas?

Connie

Burying the tank 12"-18" will work wonder at cooling your solution. the earth makes a wonderful heat sink. circulating the reservoir liquid will help to as it will increase the amount of fluid contacting the sides (and thus the earth).
Another solution would be to watch your local craigslist. I often see people getting rid of refridgerators for little to nothing. just get on, cut a hole through it and presto! Super cooled nutes.

Duhhhhh!!!! That's a great idea, Grizzman. Can't believe I didn't think of that. Going to Craigslist now.

Connie

I think that shade and possibly a fan to keep the air moving will allow the plants to do their own cooling. I haven't tried it myself, but I wonder how one of those misters would work along with the fan? Evaporation will tend to cool things down a bit. When I had a black plastic irrigation system some years ago in Florida, it worked very well in the shade. I still have some pictures if you are intrested. My pipe was mounted on 2X4s in rows, otherwise. it was pretty much the same.

Here is a link that might be useful: old pix including irrigation pipe system

I pumped air from an old hairdryer into the nft duct, reverse flow to the water. In one end, out the other. You lose a lot of water to evaporation that way, so you must check the level daily and top up.

Burying the reservoir and keeping it shaded should be enough to keep the temperature down. If not some kind of active cooling would be needed.

I'm not sure if a fridge would be the best way to do it, though... I don't know for sure how much electricity they use, but I imagine it's a fair bit.

Underground, larger volumes of solution would help also.

This is an oldie, but a goody. I remember seeing this a couple of years back. I am surprised no one suggested painting the black corrugated pipe white. Krylon makes a spray paint for poly lawn furniture that should work. Black absorbs a bunch of heat and the corrugation offers a lot of surface area, in effect working like a solar water heating system. Just thought I would put in my 2 cents worth before this one slides back down into the depths of GW history.
Ken