Need help-High Cya, calcium, and algae

[Turbo]

The pool is nearly full (3 or 4 inches to go) and I did some testing. Ph is 7.4, cl is 0, TA is 150 and CYA is 70 - 80, probably 80 (not sure about seeing the dot). If I understand correctly, I need to aerate if possible to get the TA down. I am going to start shocking and will look at the chart to see what I need. I was hoping CYA would have dropped further. I must have drained 3/4 of the pool.

I guess I will just run high cl for now. Any suggestions?

Greg

[duraleigh]

Hi, Greg,

For a plaster pool and CYA of 80, I'd put in enough Cl to get to 30ppm.

You'll surely get to breakpoint and clean up any "bugs" that may try to establish themselves.

If you have mustard algae, you can maintain that shock level for a few days, brush frequently and run your pump 24/7. Pooldoc advises that mustard algae takes high Cl and a lot of persistence.

After that "shock", you can let your Cl drop on down to 5-10ppm and keep it in that range the rest of the Summer.

[Turbo]

30 ppm sounds like a good plan. I put in 10.5 gallons of 6% bleach last night at about 12. At 7 this morning it was all gone. Maybe it left so quick because I tried to scrub a section of the wall with ascorbic acid when the pool was low but I didn't think there was that much that stayed in the pool. Maybe so. I guess that combined with the algae did it. I put more chlorine in this morning (4.2 gallons which is all I had). I will buy some more on the way home and get the ppm up to 30. When will the chlorine level stop dropping so much?

Should I try some ph minus to get my TA down or just hope my little bit of aeration does the trick? I am going to buy a jet that will shoot the water in the air hopefully to improve my aeration ability.

Greg

[duraleigh]

Hi, Greg,

I would focus on the Cl level for now. Your TA is not at all dangerously high and I would "fine tune" that issue later.

You still have a bunch of organics in that pool and chlorine is your answer. Get a bunch of it and keep bringing it up to 30ppm as much as three times a day if you can. It may take a few days, but your Chlorine will start to hold more and more. Your water will be crystal clear and then you can start to fine tune that Alk.

PS - I believe it was the algae that ate your chlorine...not the acid.

[Turbo]

I have no way of telling how high the CL is but I kept dumping in cl to keep it high for 3 days (before putting in 3.5 gallons each day of bleach it looked way darker than 5ppm). The water is clear and I put some 14 lbs. of dry acid in and have the TA down to 130ppm (put in 4 lbs. of borax to bring ph to 7.2). After the chlorine drops I will put in a little more and get it to about 100ppm.

Anyway, I noticed that the sides have a very light green granular looking growth over most of the pool and it won't scrub off. When I vacuum it looks like light green granular chlorine if that makes sense. Hopefully, it will decay and come off slowly. Any thoughts as to what this is and how I can remove it?

Greg