Join Date: Feb 2012
Location: Duncan, BC, Canada
1. Find a tall glass tube (tall glass vase maybe?) that is as tall as your tank water height (bottom glass to desired water height) and maybe 2-3" diameter.
2. sink it in the tank and put your pick-up tube (from the HOB) into it.
3. fill the tank until it fills up the new glass tube.
4. turn on the HOB.
5. Monitor the level in the tube. When thet tube gets half empty, top it up. If the glass proves too light, put heavy stuff in it.
As a bonus, the water level in your tank will be very stable as only the level in the tube (vase) fluctuates.