Hi Jenn,

You asked the same question about the filter and pump a few days ago and are getting the same answer: It looks like your pump is WAY too big for your filter. A cart should NOT be blowing back into the pool unless it's damaged and the fastest way to damage it is use too big a pump. Improper cleaning, such as with a pressure washer can damage it as well. I'm not an expert on carts but they are basically big paper units. If you have a multivalve for your filter and tried to backwash it, that would have damaged the filter as well (If you have a multivalve, you'll know).

So, if the cart and pump are made by the same company (like Hayward) try calling the company and seeing if your models are compatible. If they are you STILL may have a damaged filter.

It's also possible that it's plumbed wrong, which is possible.

But I have a 20,000 gallon pool and I use a 1 hp filter.

Carl