so i got a wild hair to make one the other day, and attach it to a Marineland canister c-160. and the flow is unreal! its way to high. will drilling more holes help to reduce the flow? i was thinking yes but don't want to do something i can't undue.
the PVC is only 8" long (on a 29g) so would a longer bar also help to reduce the flow?
There's no build up of pressure in the filter housing/impeller from messing around with the flow, tattooed? Looks cool though, but I'd agree that either bigger holes or more holes will solve your problem.
Most impeller type pumps don't suffer from having the flow choked down as long as it is after the pump. Not much pressure is building up. Heck the pumps we use can barely lift water 6 feet. The only downside is the wasted electricity and excess heat from using a bigger pump than you need.