Ohio Fish Rescue nitrate test

[Coryloach]

Although I'd never recommend one using filters as siphons, I use pre-filters to prevent detritus going into the intakes, that kind of flow described above in practice will sweep the bottom spotless...as long as there aren't big objects on the way as the return of the flow is along the bottom, doing a sweep movement.

The tank on my video is round, so the flow is set up differently but the aim is the same. With round tanks you need surface and vertical flow at the same time.

 

[twentyleagues]

Circular flow, or apologies, the more proper word is linear, is achieved when flow moves either back to front or short side to the opposite short side. So the flow reaches top to bottom making a full circle. If the flow is reaching two adjacent sides of the tank simultaneously, it is not circular, nor linear.
If you aim all outputs parallel to each other in the same direction, the flow will reach the opposite side of the glass along the surface then hit the opposite glass and slide down to the bottom, turning back and travelling along the bottom, to the intake(same side of outlets), achieving full circle and sweeping everything along its path, including moving all water around the tank. If you have circular flow in the tank, your surface will be moving plenty.

Oh I see what you are saying. No I have mine purposely aimed to minimize surface agitation in the 40b. I want that to be a mostly floating plants.