Hello so question for everyone. When selecting a proper pump for a UV sterilizer and taking into account head pressure do I really only need to calculate that from the return pump into the UV and not really worry about the back into the tank amount since technically I want to relay nail the amount going into the UV, right? So say from pump to UV is 2 ft and 1 90 degree turn = head pressure is 3ft? even though there would be 1 more 90 degree and another 3 ft into the tank.