[fishgate]

Originally Posted by needmore-reef

Why not use an appropriately sized pump? Are use making use of a pump you already own?

This is an all new setup. I have the overflow rated at 300gph. Ideally, I'd like the return pump to be able to flow 300gph at the tank level. This means some amount higher than 300gph rating to get the proper flow into the tank. I will lose some pressure in the pipes, radius's and outlet not to mention losing something more as the pipes get growth inside them and as the pump ages. I think I will always need to have a ball valve to match the pump to the conditions and I don't see any way to have an "appropriately sized pump" unless I am ok with always running below the overflows rated capacity as I will always want my overflow to be at or greater than the return pumps flow capacity. So the next best solution is to get a pump rated higher and crank it down as needed. Which is what I am doing with my 700gph mag pump.