Pool still green

[boy named sue]

Greetings,

New problem, I’ve never had before. After 10 days of adding bleach (174 oz, 6%) everyday and one box of Borax everyday the pool is still green.
- In ground concrete pool, 24,000 gallons
- Mesh covered during winter, didn’t open pool last season
- Sand filter
- FC 0/0
- PH 6.8
- ALK 80
- TH 200
- CYA 0

No visable signs of algae

PH and FC go up to normal levels but don’t last 24 hours, won’t stabilize. I bought some CYA at Wal-Mart but don’t understand how to add. I’ve had the pool for many years but never had pH or CYA problems before. Thanks

[waterbear]

Just curious, what is your TC as tested with an OTO test (liquid turns yellow, usually found in cheapie 2 way drop based chlorine/ph testers). the results might give some enlightening info as to what is happening. I assume you are testing with strips since you gave a TA of 80 and that is one of the graduations on the strip and you also gave numbers for Total hardness which is what strips test for. Drop based kits test for calcium hardness which is a bit different.

[boy named sue]

Yes, you're right I did test with the strip yesterday. I have a 6 way hth drop type kit so here are my new numbers:
pH 7.8 (finally stablized, got 2" of rain last night, would that have inpact?)
CL .2 (I haven't added any since Friday night)
CYA 0 (I'm using the old sock method but haven't been able to raise)
TH 70 (I'm thinking this will correct itself when I get the CL up, right?)
ALK 100
Any help would be much apprecated, Thanks

[duraleigh]

Sue,

1. I'm puzzled about your pH. What have you been doing to move it? What do you mean "it won't stabilize"? What pH are you shooting for?

2. I'm gonna' suggest a big dose of Chlorine for your pool but not 'til we get a better idea of what's up with your pH.

3. Your other numbers are fine and we'll help with your CYA but I'd like that info on pH first.

4. As an aside, how have you handled CYA in the past?

[boy named sue]

1. I opened the pool 10 days ago and over that time added 7 boxes of Borax. pH would go up to 7.8 but drop right down to 6.8 (or lower) after 24 hours. I was also adding 174 oz, 6% bleach at the same time, CL also droped to about 0 after 24 hours. I was expecting pH to stablize around 7.6?
2. A big dose of chlorine sounds right, how much?
3. OK
4. The pool guy said to add CYA by gradually releasing it via an old gym sock placed in the skimmer. I did this but CYA number hasn't increased.

Thanks

[duraleigh]

1. Adding 28 lbs of Borax makes me think your pH was below 6.0 before you started. Did you test it?

2. Have you been chlorinating with pucks in years past? That would provide some answers.

3. If your pH would bounce up to 7.8 and then recede to 6.8, something else was going on. What was your Alk result when you first started.

4. Your Calcium (TH) went from 200 yesterday to 60 today....that's not really possible.

I'm guessing here so it would really be helpful if you post back accurate test results. That said, I would put in 6 gallons of 6% Clorox tomorrow night. That'll Shock your pool and start clearing out any organics. I would suggest the same the following evening because with no CYA (or very little) the Sun is going to burn up your Cl in the daytime.

The next AM, I would backwash the filter well and then add 7 lbs of CYA dirtectly into the skimmer. It'll take a few days, but that will get you up to around 35ppm or so. However much is left in the sock, you can dump it in the skimmer and include it in your 7lbs (remember, it's wet...you'll need to compensate)

From there on, I would test Cl each evening and add enough to bring you to 4-6ppm.

Assuming your pH stays at 7.8, I would like to see you take it down to 7.2 with muriatic acid. 1 quart should get you pretty close. Add, wait at least overnite, test again and add again if necessary.

You would help yourself (and us) if you would perform a complete set of tests each day:
CL
pH
Alk
CYA
(I assume you can't test for combined chloramines)

Your pool has had some puzzling issues. My best guess is innaccurate testing methods. Hopefully, this will put you on your way to a happy pool.

[boy named sue]

Thanks, Dave

Yes, in prior years I used liquid chlorine from the pool store and/or hth sock-it shock once a week and supplemented with pucks in the skimmer. I now understand the pucks aren't a good idea. pH unually needed to be adjusted only at the beginning of the season. Using strip testers ALK and CYA never appeared to be a problem. I guess I've just been lucky however algae has been a problem off and on over the years.

I added the first batch of 6 gallons chlorine last night. Will do full testing this evening and post results. Heavy rain here today in NJ. I may not have lost too much Cl to sunlight. Should I still add the second batch of 6 gallons?

[aylad]

You don't necessarily have to add 6 gallons the second time. You need to test and find out what your Cl is when it's time to add, and then add whatever amount will take you back up to shock level.

Janet

[boy named sue]

OK after adding 6 gallons of 6% bleach last night my new numbers are:

Cl 5 (tester only goes to 5, proably a little darker than a 5)
pH 7.5
ALK 100
TH 0 (tested this twice, zip nothing, is that normal?, it was 70 yesterday)
CYA 0

Based on prior advise from prior post, my plan is to add 6 more gallons tonight, and add 7 lbs of CYA to the skimmer tomorrow morning...

[boy named sue]

I've been trying to get the green color out of my pool. No visable aglae, just green. Based on a prior post I added big dose of Clorox (6 gls Sunday night, 6 gls Monday night, backwash this AM and 7 lbs of CYA). Numbers as of last night, before the additional 6 gls:
Cl 5
pH 7.5
ALK 100
TH 0 (tested at 70 on Sunday?)
CYA 0 (s/b higher tonight)

As of this AM the green color has not diminished at all. When can I expect improvement? I'm ready to flush and start over.