This forum is a great source of information! I've already spent a number of hours reading, and have ordered the K-2006 test kit based on advice here.

At the moment, however, I have a question about the filter on our pool.

We are running a 1500 gph pump that came with our Summer Escapes pool, with the original cheapo filter cartridge. After reading here, I was ready to order the Unicel c-4607 as a better-quality replacement. However, the specs of the Unicel cartridge describe 1 15/16" top and bottom openings, whereas the current cartridge has 1 3/4" openings. I think that may be the difference between the 'C' and 'A' cartridge varieties...?

It seems to me that if the Unicel cartridge really has a 1 15/16" opening, it may not fit snugly onto the connection inside the pump housing, allowing water to bypass the filter. Does anyone know for sure that this Unicel cartridge actually works on the 1 3/4" fittings?

I've looked at the Unicel replacement guide, and they mention a c-4306 filter with a 1 3/4" opening (it is further described as a replacement for a General Foam Plastics filter; and I think GenFoam used to be associated with the Summer Escapes pools ?).

All the posts I've read here describe the c-4607 as a replacement for both Intex and Summer Escapes cartridges, but I just have trouble imagining how something with a 1 15/16" opening will fit snugly enough in the pump housing we have.