Over the last pool season my Sta-rite S7D75 filter has been sending increasing amounts of DE back into my pool. Pretty obviously worn out filter grids. I've tried and failed to remove the manifold that holds the grids in so I called a maintenance guy to see if he would have better luck, and he did not. My possible solutions at this point seem to be to either cut the union that connects the manifold out and put in a new piece or to replace the filter altogether. Obviously the first option could be much cheaper, but I run the risk of my custom plumbing not working. I'm not super excited about doing this myself, and I'm worried about throwing more money into something that may not work out anyway. The pool maintenance guy was trying to sell me on a sand filter, and honestly it sounds a lot easier to maintain than this DE one. He's sending me a quote. I know from a cost perspective I'm looking at the difference between roughly $200 to try to replace the filters (with a lot of mystery variables) and probably $1k to get a new filter installed. Or maybe there's a middle road where I learn to be a plumber and order and install a filter on my own. My current plumbing experience is limited to capping a broken vacuum line. I'm kind of at a loss and could use a little experienced guidance. What would you do? What should I do?
Filter woes
- Thread starter CSteen
- Start date
I don't know what the inside of your filter looks like where you are having trouble. Add a picture?
All filter types have their pluses and minuses. Take a look here: Pool Filter Comparison - Trouble Free Pool
Honestly, working with PVC is not that hard. And if you screw up, usually pretty easy and cheap to cut it out and start over.
All filter types have their pluses and minuses. Take a look here: Pool Filter Comparison - Trouble Free Pool
Honestly, working with PVC is not that hard. And if you screw up, usually pretty easy and cheap to cut it out and start over.
I'll try to get an actual photo up later, but here's an illustration from the manual.
Oh man. What a horrible design. Honestly it seems like Sta-rite filters are the most poorly designed. I have seen bad things about the cartridge filters too.
This is an old swim-quip design, before sta-rite bought them out, and before pentair gobbled sta-rite up, the internal grid/manifold is classic 70's swim-quip, swim-quip made the hrp sand filters with all the bolts that held the two tank halves together.
It probably is not unscrewable by hand, your gonna be needing one, possibly two pairs of big channel lock pliers to unscrew it, if that doesnt seem to do the job (i would have that unscrewed in two minutes) then get a cable saw, position far enough below the collar and cut it off, then just couple it back together with a 2'' pvc coupler, you probably don't even need to use glue just sit the manifold and union with the exposed 2'' pipe below the collar and press it on.
the 2 wing nut's that hold the manifold assembly together may be corroded to the long bolts they connect to, but you'll just have to see how that ends up as you go along, if the bolts , nuts need replacing then replace them, those grids used to be available individually, but don't know if it is only sold as kit now or what, check into it,
It probably is not unscrewable by hand, your gonna be needing one, possibly two pairs of big channel lock pliers to unscrew it, if that doesnt seem to do the job (i would have that unscrewed in two minutes) then get a cable saw, position far enough below the collar and cut it off, then just couple it back together with a 2'' pvc coupler, you probably don't even need to use glue just sit the manifold and union with the exposed 2'' pipe below the collar and press it on.
the 2 wing nut's that hold the manifold assembly together may be corroded to the long bolts they connect to, but you'll just have to see how that ends up as you go along, if the bolts , nuts need replacing then replace them, those grids used to be available individually, but don't know if it is only sold as kit now or what, check into it,
Interesting idea to use the collar, @Realaxpooltech. I'll have to get a cable saw. I saw a full set of grids of Amazon for $155. I may give this a shot.
@Realaxpooltech I purchased two different couplings. If what you were referring to is like the one on the left, you think just slotting the pipes into the union is enough to keep it secure without gluing? Awesome if so. Would make removal easy easier in the future. 
After two years of trying I finally got this filter apart. I used a big pipe wrench to hold the top of the union and a strap wrench to turn the part that needed turning(clockwise). It was almost easy enough to make me mad. Almost every filter grid had tears near the top where they connect to the manifold. About to order a replacement set. Looks a bit like a poor design me. Regardless, should be swimming next week.
I
IAfter finally getting this thing out I noticed the manifold can separate if I apply a little pressure. Is this a concern since it will be held together with a wing nut when reassembled? If so should I try to glue it with some pvc glue, or am I better off dropping the 120 bucks for a new part?
So it looks like you were able to unscrew the union, so you don't need the 2'' pvc coupling, which also means you did not cut the pvc pipe below the collar with a cable/wire saw, correct?
As far as the separation in the manifold, glue it, wrap a couple zip ties around it, etc. The wing nuts will do there part also.
Resist the urge to over tighten the wing nuts, this can put to much pressure on the grid assembly, which can crush the grids over time as they compensate for being to tight. tighten just enough so grids stay in place.
As far as the separation in the manifold, glue it, wrap a couple zip ties around it, etc. The wing nuts will do there part also.
Resist the urge to over tighten the wing nuts, this can put to much pressure on the grid assembly, which can crush the grids over time as they compensate for being to tight. tighten just enough so grids stay in place.
@Realaxpooltech Thanks for the feedback. I'll add a little glue and not over-tighten those wing nuts. The bottoms of some of the grids had some broken plastic, which may have been a clue that they were overtightened before.
I reassembled the filter with the new grids. There's a pretty steady slow drip on one side of the filter housing (maybe a drop every five seconds or so). I'm also hearing an intermittent swishing sound from inside the filter, maybe every 20 or 30 seconds. Sounds sort of like a dishwasher, but not as constant. I flipped it on and left it, but the timer flipped it off (I need a new timer). It probably ran for at least an hour, but it may have been going for a few hors before the timer kicked it off. I've got it off now and I'm concerned about turning it back on. Any theories or thoughts?
I opened the filter again and took a look at things. The air bleed house had come off so I just stuck it back on again. Not really sure how that thing is supposed to be secured, but the pressure of inserting by hand seemed like it might be enough to hold it. I also noticed the o-ring on the filter housing is slightly slack around the base. There's probably 1/8 of an inch of gap for an inch or so when I pull the ring around the collar. Is there any danger running things like this while I wait a few days for a replacement ring?