I use a peristaltic pump (fixed rate 120ml/min) connected to the Aquatronica. Right now it is set to come on for 1 minute, every 2 minutes. This provides a flow rate of 55ml/min. (120ml for the first minute, 0ml for the next minute) Flow is controlled by varying the time on/off by the second.

Here's the pump I use. This CDN company has been easy to work with and delivers promptly.

http://www.omega.ca/shop/pptsc.asp?r...100&Nav=grel07

http://www.canreef.com/vbulletin/sho...t=28436&page=8

I use a slightly smaller version of the same pump to push water through the Kalk reactor in the exact same way. For both pumps, I went to RP Electronics and purchased a holding box and power cord to wire them up with.

For you, the trick is to purchase the correct size of pump. Measure your current flow in ml/min, then purchase one that is exactly what you want (run it continuously)..or get a larger one and cycle it on/off for adjustable control.

I use the aqua lifter lift pump works great

http://www.oceanproaquatics.com/shop...oducts_id/1926