Guess my filter... please.

[CarlD]

Yipes! Ted is the guy on DE.
I thought it wasn't a cartridge because you have a multi-valve on the side. They are not common on cartridges. Most of the junk (yes, it's junk) from the pool store shouldn't be used. If you can return it, do so. I'd keep the DE and the liquid pool shock, but ONLY if it's sodium hypochlorite. If it's "non-chlorine" get rid of it.

Phosphate remover is the latest junk chemistry the pool companies are pushing. If THAT is your problem you have far worse problems. I don't know anyone who has actually needed that stuff--PoolDoc MAY have, and Waste and Waterbear could as well...maybe.

Not sure what the "blast box" is but I'm guessing it's packets of Cal-hypo or Di-Chlor. If so, you can use those, too.

What is the horsepower on the pump? And how many gallons is the pool?

[waste]

That's quite an algae collection you had there

You want to rinse the o-ring and wipe down the sealing areas on the tank before lubing and reseating the o-ring. The lube should be either Teflon or silicon based (NEVER !!!! use petroleum based lubes on pool parts!!). When cleaning the o-ring or lubing it do not pull on it or stretch it! all you're looking to do is rub the lube on so that the ring doesn't dry rot and will allow the top to slide into place without pinching or tearing the ring.

Getting the clamp back on isn't overly difficult.

1) Lube the o-ring and seat it on the bottom part of the filter.

2) On the top there is a little tab, line that up with the slot on the bottom (where the multiport is) and lower the top onto the bottom as levelly as you can (it's not good to turn the top once it's touching the o-ring).

3) Your band has 2 spring loaded nut assemblies, you removed one nut, spring and the 2 washers to get the band off. Loosen the other nut ~ all the way and put the clamp back on (orient it so that you'll have easy access to both nuts). You should now be able to start the slevednut/ spring & washers assembly that you took off.

4) Tighten the nuts. Go back and forth between the 2 sides so that the 2 gaps in the band remain within ~ 1/8" of each other (we're trying to keep even pressure on the o-ring to insure a proper seal) Do this until the coils on both springs are touching then give each side ~ 1/2 turn further and you should be all set to go

It probably took me longer to type this than it will take you to lube the o-ring and get the filter back together

Keep us posted as to how you are coming along.