outside resevoir cooling

I ran my resevoir outside my case and would like some suggestions on cooling the water down it's about 3.5 - 5 gallons. Don't say ice that's just a temporary solution. Since I have a 1/2 rad do you think it would help if I increased my lines to 1/2 instead of 3/8 ? Any additives that might work to cool it down.
Already have water wetter.

Unless you're willing to go to some type of phase change solution to chill your water, I would say leave it alone.

What are your ambient temperatures? I've found, since I use a 5 gallon bucket as a reservoir, that if I can keep ambient temps down, then my water temps stay down as well.

You have to remember that with a large reservoir, temps are slow to react though.... but as I've found, if your dumping warmed water into the top of the bucket and drawing cooler water from the bottom, you shouldn't have a problem.

Jeremy

You could take off the cover of the res and mount a case fan blowing into it (or your radiator exhaust). This would give a bit of the evaporative effect that makes bong's so efficient.
You would have the humidity increase in the room, and you would also have to keep an eye on the water level, but it would help the cooling out.

Having used an outside reservoir and radiator, best bet is a larger radiator and fan. I am using a 24 pass cooling coil from a walk-in cooler as my radiator, cooled by a 160mm AC Orion fan. Keeps temps about 3-4C above ambient. Loud as hell, though. Alpha's statement about keeping ambient down is accurate as well. Your idea of increasing your line size should help.

your using a similar setup as i am temporarily but my container is a rubbermaid 54qt tub, its like 2.5ftx3.5ftx1foot deep, i have it filled with 6gallons of tapwater, with some ajax and a little drop of dishsoap... and it cooles to ambient... stays there unless its really humid... when very dry, it cools like 1-2c under ambient... id say use that radiator, get a 1/2-3/8 adapter from your local hardware store....