another loud drain. plastic gate valve?

[mark]

had a 33g QT tank and playing around did a Herbie with no overflow. Wouldn't recommend running permanent since overflow chambers are easy enough but could try a Herbie.

On the inside just do the 2 upturned 90°s, with one stub say a couple of inches below where you want your water level, second stub just a little above where you want the level. Gate valve on the line with the shorter stub, got a Herbie.