Get rid of that hard pipe and get some 3/4" black flex tubing and 1x 90. Place a 90 on the return side of the UV. Take the tubing up and out of your cabinet. Get a 1000gph pump and tune it for about 250gph. It will take about 15 sec to fill a 1g milk container. Do this measurement out of your return nozzle in the display. My return is running at 1650gpg and I get 400gph. They lie when they rate them. I would guess that 1000gph full blast will yield you 250gph through 3/4" tubing and the UV. Your Axios is probably perfect.