Green pool with clogged sand filter after 2 weeks out of town

[FormerBromineUser]

If you have time, you can slowly add the borax to skimmer, wait around 2 hours, and then retest PH. Add more borax as needed. You need to get that pH above 7 as soon as you can.

[jtran69]

Thursday night I added 2 gallons of bleach and 1 box of borax; PH was not quite 7.0 but more likely 6.9.
Then I added 4 more cups of borax.

Friday 11am, PH=7.2, FC=10.5.
Then I added 3 cups of borax and went to work.
Water is looking better now but seeing some black/gray dirt on the bottom -- another round of vac should remove them.

Friday night plan, please advise.

[FormerBromineUser]

Get your FC up to 25 ppm tonight. Retest 1 hour later to make sure you hit that target. If not, add more bleach. If you have time over the weekend, maintain FC at 25 by testing and adding bleach at least 3 times per day. Some people only recommend 3x/day but I think a 4th would only help if you have time. And no more Di-Chlor panicking!

[jtran69]

At 8pm, pH=7.6. I added 2 gallons of bleach.
At 9:30pm, FC=18. I added 1 gallon of bleach.
At 11:30pm, FC=25. Yes yes yes!

[SunnyOptimism]

You need an accurate CYA measurement in order to know where you are at so you can target your FC properly. Please do a dilution test - mix 1 part pool water with 1 part bottled or distilled water and then redo your CYA test as normal. Take the results of that test and multiply by 2 to get a correct CYA value.

[jtran69]

5:30pm, FC=15, pH=7.5. I added 1 gallon of bleach.
I have about 10 ml of R0013 left for one cya mea and will take it when FC is back to 25.

[SunnyOptimism]

You can get 2oz refills and even huge 16oz bottles on Amazon. I have a 2oz bottle that I'm about 1/3rd the way through (16oz is kind of crazy big for a residential pool user).

Good luck and I'll keep an eye out for your CYA result. My fear is that your CYA is crazy high and 25ppm FC may not be adequate for a shock level. Also, when your pool is clear, knowing that CYA exactly will help you target a proper FC keep the algae at bay. If it's really high, your pool may warrant some water draining to help get your CYA down...not fun to dump water but the alternative for an over-stabilized pool is to run at a higher FC level which means more bleach and more frequent bleach additions which can be costly too in the long run.

First things first, get the pool sparkly again, then worry about stabilizer....

[jtran69]

I've done a vac earlier and the water is looking really good now. My kids kept asking if the water is ready yet since its has been 90+ over the last 2 days.

[Watermom]

but the alternative for an over-stabilized pool is to run at a higher FC level which means more bleach and more frequent bleach additions which can be costly too in the long run.

Actually, pools with a higher CYA usually can get by with less frequent dosing with bleach. Some people deliberately keep their CYA on the high side for this very reason.