So I have a question. I recently bought a house with a massive old inground pool in it. Size is around 38x20, based on my crude calculations should be around 110000-125000 liters ( 31000+ gallons).
Currently has an old ez-flo 1 speed pump and an old big sand filter.
So yesterday I yanked the old pump and put in a pentair superpump VS for more efficiency and automation of timings.
Question is about the filter. The sand filter is working OK I guess, but when doing cleaning the pressure raises fairly quick from the regular operating psi of 15 to 20 and eventually 25 rapidly. So I got lucky and got a brand new pentair clean-and-clear cc200sq/f cartridge filter. It's brand new in box and I got it for 160 bux! Which is a steal! But when I went to the pool store and they literally and I mean literally laughed at me! Saying it is so small of a pump (it's actually the biggest one of last generation of pumps which is discontinued now)... Saying I need a 460sq/f system which has 4 smaller filters instead of the one big tall one in mine!
Question is, are they just trying to get me to buy a bigger filter from them? Right now with the VS pump my psi in my sand filter is super low (near zero but obviously at least a couple PSIs) so wouldn't the cartridge be fine too? Are they saying it's too small for when I increase the speed for cleaning and the size isn't adequate to push enough water through and I would get psi problems? Or do they mean I would just have to yank the filter out and clean it much more often than a bigger system? Cause I'm OK with cleaning it. Even now I almost have to backwash daily or every other day as is.
I was so excited not to have to do backwashing since my pool has backwash hose buried and brought to the front of my house, so it's a hassle to go there, hook up a backwash hose to the exit, then pack it all up daily!
So what say you guys? Can I get away with the 200sq/f filter? I'll probably be running the pump at 600 or so rpm for about 14 hours a day (haven't done the gpm calculations to figure out the exact flow rates yet) so I can't really see psi issues with the filter...