Hi Greg;

Your pump run time was fine -- given that you had a DE filter. However, because a DE filter will remove algal spores and early algal growth, it will tend to stall algae development longer if you run it 24/7. But, if you maintain an adequate chlorine levels, 8 hours of DE filter run time is plenty . . . with clear water. Just remember that whenever you're having problems, you need to switch to 24/7 run times.

You can not trust pool store testing, ESPECIALLY when it's based on strips. Strip based testing is NEVER trustworthy. Titration and color match testing may, or may not be trustworthy, depending on the store. But, since you don't know, you're right back at not being able to trust the stores!

Buy a cheap OTO/phenol red test kit from Walmart or wherever, but ALSO, if you can afford it, buy a K2006 FAS-DPD testing. Right now, to fix you up, we need to know your CYA (stabilizer) level.

Also, any time you are low on chlorine, and need to raise it quickly, just add plain unscented 6% bleach. Assuming a 25' round with 48" water depth at ~13,500 gallons, one gallon of 6% bleach will add about 4 ppm of chlorine to your pool.

The trichlor from Sams is perfectly fine -- your dealer is either ignorant or dishonest. The dichlor at Sams is also fine, and unlike most pool store dichlor is both very cheap (below wholesale) and un-diluted. But, we need to know your CYA level, before you go get a bunch of chlorine with stabilizer in it.

If you can, get a K2006, and test your CYA. You can use the Amazon order link in my signature, if you like. If you can't afford one (~$70 for the 3/4 oz size or ~$110 for the 2oz size) take your water samples to several different stores, and see if you can find a store that will test your CYA with something besides a test strip.

By the way, with bleach, a DE filter like you have, and our instructions, you should be able to clean up any algae problems in a week or less!