This build below can cool two 1000w and one 600w HID lamps.. I made 3 of the 8" Iceboxes and this A/C to chiller conversion, then I set up three 4x4 tents in a bedroom, using a 1000w lamp in two of them and then a 600w in the third for the guy's veg room. We sealed off the tents with silver foil tape to use Co2 in all three tents, and this damn cooling system was cooling everything just fine. All his lights was creating about 9,000 BTU of heat and the chambers were a perfect 84*F with an outside temp in the upper 90s... Here is how we can use water to cool our chambers and or HID lighting. First we will build an 8" DIY Hydro Innovations Icebox.. You will need some sheet metal, an automotive heater core, some foil duct tape, and two 8" duct take-off. (I bought a heater core on fleabay for $7... The heater core is 10" x 6" x 2", so I took some sheet metal measured it out to 12" x 8" and rounded the corners so they're not sharp... Then I bent up the 2" edges so the heater core will fit inside the sheet metal box. Because the heater core is only 6" high, I had to make up the 2" with Styrofoam.. Then I used a duct take-off to make a circle to cut out so I can install the 8" take-off. After I got the *" duct take-off installed this is what the back of the Icebox looks like with the heater core. Then I used an 12" x 8" piece of sheet metal, bent all the ends so it fit like a cap, then cut out a notch for the inlet and outlet heater core tube, and installed the other 8" duct take-off to the top cap. I then put the cap on, using the silver foil duct tape to seal the Icebox up. This Icebox can easily remove the heat from a 1000W HID lamp (3,410 BTU) Now we can also convert a $100 Window A/C Air Conditioner into a 12,000 BTU Chiller This unit can sit in a window and it will look like a normal Window Air Conditioner from the outside. I took a 12,000 BTU Air Conditioner and took the cover off. I removed the Styrofoam divider (this divides the cool side from the hot side) We need to remove the cool side's fan.. On this A/C unit both hot and cool side fans were run from one motor, and I was able to simply hacksaw off the cold side fan. Then I took an old plastic toolbox using it as a reservoir slipping it under the evaporator, but you can use any small tote. I then made a piece of sheet metal putting it between the condenser fan (hot side) and reservoir (toolbox/cold side) I then put the cover that I first took off over the toolbox/tote/res so I can measure it to cut the cover down and get it to fit back on. Lastly I put a 140ghp pump (had 6' head pressure) in the reservoir and you have a 12,000 BTU water chiller..