I had NO stabilizer in my water at all, because we got the pool completed late in the season last year, and had no pump or filter, so all I added was enough chlorine (based on guidance I got here) to keep it from becoming a swamp. So this season I had to add it, to get the minimum required level.
The pool co I hired to open the pool for me (since I’ve never owned a pool ever, and the pump/filter needed to be run for the first time and checked etc) dumped a ton of chlorine in the pool to shock it, not realizing I had NO stabilizer in there. I didn’t know I needed it (I explained my confusion on that subject) and the pool store employees told me I shouldn’t add it till after I finish “shocking” it.
I added almost 8 lbs so far (there’s about 1.5 lbs left in the 8lb bag) but the pool math calculator says I need to add 136 oz, which is 8.5 lbs.
I have stopped adding it today to see how the numbers look later.
Did I miss what kind of filter you have? I'm still learning this forum but I checked your info page and skimmed through the thread...
I would guess you have a sand filter based on your description of events and observations.
What I would have done after taking your original measurements and pool water conditions follows. I use this routine to save chemicals and time. It works every year on my swamp reveal (mesh safety cover makes it worse). These are rough numbers based on my 30K vinyl pool which is close to yours in volume. I'm going by my previously calculated opening plan and your initial measurements, but not to your exact pool volume.
1) Manually and slowly vacuum the heavy Crud from the floor and lower sides to waste; try not to stir it up. Adjust water level to normal.
2) Shock at about 10-15 ppm liquid chlorine (LQ), run the filter 100%, skim the surface often, and continuously change out filter socks until the water is gray or blue looking. It will be cloudy but that's OK for now. Shock twice, about a day apart, to make sure you keep the level up and kill chloramines.as well as bacteria. It's slight overkill but it's cheap and harmless if dosed properly.
3) Backwash the filter as necessary to get rid of the majority of dead bio material.
4) Once the filter can be run for a few days without totally plugging up (usually takes me a couple days to reach this point) I'd take care of the balance issues in one shot. I'd add two ~13lb bags of baking soda, 1/3 bag per bucket of water at a time to get it mixed quickly. Slowly add 8lbs of CYA through the closest skimmer to the equipment. It will stay in your filter and slowly dissolve and distribute safely over the next few days. DO NOT BACKWASH for a few days. Add a daily maintenance dose of LQ if necessary to keep FC around 5ppm. Don't worry about PH yet. It will creep towards normal due to the baking soda addition, plus keeping it slightly low for now is beneficial.
5) After 3 days you can backwash the filter. The water should be clear enough to see the deep end if not nearly crystal clear. The floor will be dirty from dropout, that's OK. I wouldn't waste time vacuuming to waste again and I don't want to stir it up yet. I use a dummy pipe in place of my SWG during the above procedures until this point when I install my SWG. I didn't mention it above but during the 3 day CYA dissolving period I would test and add all the salt I need to reach 3500ppm within the first 2 days. Dump the salt around the sides then slowly brush it into the main drain to distribute. Run an automatic vacuum if you want. I have a cheaper Dolphin; I don't care if it succumbs to salt water or high chlorine level damage. It's been going fine for many years without any repairs.
6) You'll need to augment chlorine as the SWG is put into operation. It won't be able to build up from zero to your target FC level by itself unless it's a monster unit. I run mine for one day in "shock" mode while adding LQ in small doses. Then I run it at 40% during the hot season. The SWG will raise PH so your PH should be normal in no time. If you don't use a SWG then ignore all SWG advice and simply adjust PH up in step 5.
7) Your water should be pretty clear now, so CYA test will be more accurate (it will also be in range where the tester is more accurate). If you are using test strips, stop. Get the liquid turbidity test with the sight tube. Do not raise CYA as high as your last readings would suggest. Hopefully you just got a bad reading. 8lbs of CYA should have gotten you in the low range of good. I like to run about 50-60ppm early on as it will slowly go down over the season due to SWG operation and water replacement.
8) Test TA and add baking soda as necessary to get it around 80ppm. You'll need to add a small dose of BS about every month to maintain. A higher TA level can have negative effects on chemistry; there's no reason to run 120ppm or more as is often suggested by chemical and equipment literature.
9) I have a DE filter which traps that tiny dust-like dead bacteria whereas my old sand filter did not. So now instead of vacuuming the floor to waste (frequently) I vacuum the remaining Crud on the pool floor into the filter. Then I break it down and clean the grids once which lasts me the whole season. I only backwash and recharge the filter and vacuum to waste once each during startup, saving a lot of water.
It took 1 week and about 6 solid hours of work from removing the cover on a swamp to achieving crystal clear, balanced water this year.
