I have no personal experiance wih a water cooled light but i have water cooled my computer and the parts are the same really.
First you need a light fixture, second lines for the water, third a water cooler.
The pricy part comes with the water cooler. You have two choices here...
A radiator style that cooles the water using air just like your car. Plus to this is its cheaper, cons are its less effective and then you still have heated air to deal with, second con is the water is only as cool as the air thats used on the radiator. Not usally a big deal however unless your in a hot state.
Other choice is a self contained water chiller, and you need a pump. Plus is less mess, can set temp of water, not as much hot air, pump is built in. Cons are price.
Air cooling is louder, less efficent, and bigger bulker parts. The plus is that is easy, no water on your pricy bulb or over your plants. If something happens in a air cooled system the effect will be less costly and easier to fix, plus less potential damage to other stuff. Imagain the pain caused by a water cooled light that leaked coolant all over your plants then burned up cause all the water was gone taking out your water chiller with it.
With that said.... i use old fashion air cooling and have never had a problem with heat. Only con is the little bit on noise from the fan but it has become music to me and the soft weeering of it helps me sleep.
Now about my pc cooling with water exp... have never had a problem with a leak. But it made me sleep like crap thinking about all the bad things that could happen if something did go wrong.
Lastly. If i was building a stealth cab such as a dresser i would go water cooled so i can still use a 1000 in that little space. Full sized room then air.
And fyi... with good air flow i can place my hand on my air cooled glass all day without it feeling very hot. Have tops within 8 in of my hood. Have seen leaves on a water cooler with no burning.
