I've tried the RedSea DIY CO2 on a 36 bow, and I'll warn you know you will get zero benefit out of it. After migrating it to a 20L, I realized it was wasted there too. The change in results going to pressurized was off the charts.
I currently use the little pump it came with to drain my tanks. I have non-CO2 plans for the bottle as well, but I still consider the whole thing a waste of $30.
Based on reading here, I've decided to stay away from paintball setups. I'd also recommend an extra check valve before the rig. I've learned not to trust those cheap builtin check valves.
Also be warned that those 6' sections of CO2 tubing on ebay aren't really CO2 quality. They're just cheap standard tubes and will break down in a month.
Brian_Cali77, don't you mean a Milwaukee rig? They're the only cheap (new) ones I've seen on ebay that have bubble counters. Aren't those $80 Aquateks paintball?
Eheim Pimp #513 (Classic 2217 and ECCO 2234)