I don’t know if you noticed it in the pictures but I also incorporated a closed loop system. It is mostly to have a better way of plumbing the UV but it also offers a solution for getting better flow along the long front of the tank.
It starts out with two 1-1/2” low profile strainers that get plumbed together. I did two so that if one got covered, it would be unlikely that both would get covered. Then it continues to a ball valve, and then opens up from 1-1/2” to 2” plumbing and goes through an apex flow rate monitor and finally into the 120w lifegard pro-max UV sterilizer.
The recommended flow rate for algae for this UV is like 3800 gph so I switched my Abyzz a200 from being the return pump to the closed loop. From the pump it will go to a T where I can direct it to a drain (if I ever need to drain it) or to two 1” lines that go back to the tank with RFG’s. I’ll be covering the in tank plumbing with rock work to hide it as best as possible.