Gee, if some of that is what you're being taught at TFP, I need to read over there some. I'd just assumed they'd cloned the info here.

OK.

Volume 3.14 x 13.5 x 13.5 x 4 (actual water depth = 48"?) = 2290 cft
2290 x 7.48 gal / cft = 17,100 gallons.

Add 2 boxes per evening (slowly, to the skimmer, basket in place, pump running) till your pH is above 7.2. Don't worry about TA, CH now.

You can use bleach or dichlor to chlorinate, given your current readings. I assume "S=0" refers to stabilizer. (Is that the abbreviation they use there?)

Dichlor would add stabilizer, and you can get 50# cheap at Sams (or, probably, Costco). Look for "sodium dichloroisocyanurate" as the ingredient.

No more mixed up stuff. Save it. Once we know your filter is working, we can figure out how to use it safely in your pool.

Going over those abbreviations - you'd better repost with them spelled out. Does "TH" equal "Total hardness"?

How can you avoid heavy hauling?

Probably, you can't till things are adjusted. How old are your kids? A 3-year old can carry a box of borax -- maybe you need 3 kid (instead of a 20 mule) borax team? Once every thing is fixed up, you should be fine. The dichlor will be a pain till you get it there, but it should last most of the summer.

But, bad news: you've got the classic AG pump that's WAY too big for your filter. Send me the model numbers, and I'll try to figure out how bad it is, but there's no way matching a 19" filter with a 2 HP (no matter how they've played the HP ratings games) will work out. If this is not your first pool season, the odds are high that a lot (most?) of the sand has been blown out of your filter when you were backwashing.

You can *TEST* your filter by adding a couple of cups of DE to your skimmer with the pump on -- if you see the DE blow back into the pool via the returns, your filter needs work. I'd recommend going ahead and getting the smallest bag of DE you can, and doing the test. (Save the extra DE -- and you'll probably have a LOT -- to use for other things, later. Put it in a bucket, since the paper bag won't last, but the DE will.)

If your filter is not working well, you probably need to add sand AND reduce flow from your pump to
(19"/2/12"/ft) x (19"/2/12"/ft) x 3.14 => ~2 sft
2 sft x 15 gpm /sft = 30 gpm.
The 20+ GPM / sft rating used on AG pool sand filters is completely bogus. The 15 GPM/sft on IG pool filters is the upper end of what works well. On commercial pools, when I want fast clean up and clear water, I have always designed with 12GPM/sft. If I have multiple filters, so I can backwash independently every so often, I've gone as low as 10 GPM / sft.

My guess is, with a 2HP AG pump, you may be pushing 60 GPM, which is DOUBLE what works well. The problem is that (a) the high pressure and flow actually push the dirt through the filter and (b) the high flow blows your sand out during backwashing. If you supply your model number, I'll try to look and see if you can replace the impeller and diffuser with a 3/4 HP set, which will reduce your flow to a functional level.

Ben