What filter to buy

I currently have a doughboy silica 2 sand filter. When filling the pool( we had a new liner installed) the water was leaking from the backwash port on the filter. I looked it up and it might be the spider gasket. I called the local pool store to see if they had the part and he told me it could be numerous things and to just get a new filter. They have one a cartridge filter that comes with a 2 zone pump for 450 bucks. He said it would cover a 15 by 30 pool. I have a 15 by 24 52 inch pool. Does anyone have any recommendations on a filter that won't break the budget? 500 max.

Thanks

Tara

Sounds like a spider gasket, probably is. This pool store has just shown you that they don't deserve your trust. Have you opened the multi-port valve to inspect? Keep looking, you'll find the part you need.

Well it's not the spider gasket. We got a new one and lubed it up real well and it's still leaking bad. Strange thing is that it doesn't leak when it's put in the backwash position but leaks in every other position. Where is the multi port valve? I'm just getting frustrated and want to get this fixed already.

Is it possible that the valve roto was installed win the wring orientation? Maybe you could test by setting the handle in the opposite direction ( filter to backwash, backwash to filter)?

You installed the spider gasket IN the multiport valve. Unless your filter's tank is damaged, even replacing the entire multivalve is far cheaper than a whole new filter. BD is right: That pool store isn't to be trusted.
The only reason to replace a sand filter entirely is if the tank is damaged or it's too small for your pool or it's a model for which parts are no longer available. Otherwise, you can replace the insides, the multivalve, even the drain cap, without ever changing the main tank.

Wow! I just re-read my post from yesterday. I think my phone thinks it's smarter than me - probably is.
I meant to say: "... valve rotor was installed in the wrong ...". Yikes! Sorry.