Thanks Janet. I'll check the tabs and their ingredients.

I use tabs mostly because I'm not home for several days at a time, and my wife REALLY doesn't want to get into chemicals and maintenance other than the occasional skimming.

Last year I used tabs (usually three at a time), and supplemented or "shocked" with bleach when I needed to. This was all before getting deep into the forum and only testing with strips, so this year will be a big learning curve. Funny you mentioned late-season algae blooms, because that's EXACTLY what happened. I assumed it was due to the fact that the pool got more late season sun (it was shaded by trees for overhead mid-summer sun, but got the slanted late-summer stuff).

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A different question on more of an equipment line:

I have a Hayward 1.5 hp Power-flo matrix pump mated to a Hayward vari-flo XL valve (valve says 75 gpm max), on a swim pro sand filter (3.22 ft sq. effective filtration, filt. rate 25 gpm, 250lbs sand). Pump is basically new since the old one locked up and I just replaced it with the same specs. I remember finding out somewhere that my setup was most likely part of a kit. Pool is about an 18x30 oval 4' deep (give or take).

I'm wondering how they're matched up since I keep reading about oversized pumps and undersized filters being a problem, and I'm wary that I'm suffering from one of the effects of the dirt being pushed through the filter. I remember vacuuming thoroughly last year and the next day finding all the dirt back on the bottom of the pool.

Could this also be "bad" sand? Since I bought the pool with the house, I really don't have the history of it. Thanks all.