everyone!this is a lil contraption i tried and found it to work excellent in my setup, maybe it can help some of you out. you see i run a small recirculating dwc setup. it consists of two 5gl buckets[reserve,control] and nine 1gal buckets[1filter,8pots]. after doing some educated guessing and nute calculations i figure my system to have roughly 13.5gals recirculating at all times. when i first designed the system it[nutes] was running in the high 70's sometimes high 80's depending.
i knew that wouldnt work, i tried individual dwc last year and fought ph, ppm, temps, root rot, everything you can name. this grow i was somewhat prepared, except for the inspection but thats another story. back to the cooler chiller. i had a couple of these 5 gallon home/office "coolers" lying around and figured if it'll keep that water cool it surely would help out in my situation some at least. 
so with a nutdriver and a blunt i set off to fix something that wasnt broken, heres how i did it.this is your standard home/office water cooler.
this is the rear view, remove the two screws at the bottom
this is the top of the rear, remove the 6 screws shown here
this is the top view, grab the inside and twist it out!
here we have it out, it has only a tight gasket holding it.
remove this thingamajiggy
the next step is to remove these faucets, they unscrew a long way
back up top you can now pull out the water reservoir, lost the pic but its this thing
next you want to slide the compressor and all out carefully not to damage anything. place it next to your reserve or control bucket.
this is a few different angles of the inside of my control bucket. the white cup lookin thing is what does the cooling. i drew a line for the nute level, if it gets too low the that thing freezes up!
here is the temperature control. once you mod the chiller, let it run for a few hours checking temps often. you will need to adjust this. maybe even a couple times until you get it right, i did
it took a couple days of me checkin it every 12hrs to set it and that was months back i have not touched it since! 
after googling the mfr tag on the compressor i posted the specs where Stonewall was nice enough to translate into laymens for me.
lol he said that according to the specs this model has a 1/12hp motor and will pull a maximum of 592 btus per hour. all that being foreign i googled the next nearest aquarium chiller, the 1/10hp. they average 1k btu and will pull 100gals down 10degree or 30gals down 30degree. now im not sure of this ones potential but i know for a fact that my system is over 10gals and it the first 12hrs dropped it almost 20degrees to 62.5! 
thats when i started adjusting. lol any questions?
if not, then you may have to give him 
lol
