 Re: water flow ?
HOB's are nasty for gassing off CO2. They suck up the CO2 rich water, which wants to diffuse the CO2 upwards and gas off at the surface. Then the filter lays the water out on top of the tank, even splashing the surface if the water line is too low.
I run my tanks at 10-15gph/gal. For instance, my 20g runs an XP1 with a rio 180. I do this because of high density plants. Sparsely planted tanks don't need this flow rate nearly so much. It's all about eliminating dead space and mulm/detritus deposits.
-Philosophos |