Am I doing the right thing?

[grangerhj]

I received Ben's kit a week ago and I think I am in heaven. I do have a few questions on making some adjustments. My Readings today:

8 am - 6:30 pm
FC 4.5 - 4.5
cc 0.5 - 0.5
TA 13 - 13
ph 7.5 - 7.6
cal 220
CYA 100
12,000 gallon fiberglass pool in sunny, hot south Louisiana
Mt water temp runs between 84-86 and I have a small fountain for aeration.
I have been battling high CYA- over 160 begining of May- which I have lowered to 100 as of today by periodic lowering of pool water(12 " at a time per manufacturer) and refilling. Last week I used Metal Out and Stain out to get rid of brown stain that has been on the bottom of my pool since I first opened this spring- stain is gone and of course the day that I used it my chlorine level went to O. I have been adding bleach 2-3 times a day since I stopped using pucks in May and switched to bleach .

This morning after the first reading I added a gallon of bleach. For the last week, as long as I kept my chlorine reading above a 7- I had no CC. But if it drops, the I get a .5 cc- never any higher. I have to add a lot of bleach each day- at least 2-3 gallons a day to keep readings of fc at 7. Here are my questions:
1. Should I shock first raising to 20-25ppm and then add muratic acid to lower PH or should I lower ph .4ppm and then try shocking?
2. Could there be any other reason for my chlorine levels not holding/

I thank you all in advance for any help you can give me. This site is a godsend. I even have made a believer out of my husband because my pool water is sparkling.

[CarlD]

You are making it more difficult than you need to.

You have a CYA of 100. That means your normal range for FC is 8 - 15 and your shock level is 25.

You have CC greater than 0, and greater than .5. Therefore you need to shock.

So shock to 25, and keep it there till CC is zero.

Thereafter keep your FC AT least at 8ppm.

That's all unless you drain and replace water to lower CYA.

[grangerhj]

I always seem to make things more difficult!!
Thank you- I will shock tonight. I will add muratic acid tomorrow if my ph continues to stay at 7.6

[CarlD]

. I will add muratic acid tomorrow if my ph continues to stay at 7.6

WHY????? 7.6 is FINE pH. You ARE making things more difficult. If it ain't broke..... In fact you listed Total Alkalinity as 13--that is WAY too low. If it's really 130, you are fine.

I don't see why you want to lower a pH of 7.6. LEAVE IT ALONE!!!!!

[grangerhj]

Sorry TA is 130 not 13. The reason I was going to lower ph was because I read on this site that if you have metal in your water that it stays in suspension better if you maintain a 7.2 ph. If you do not think it is necessary to lower a 7.6 ph believe me I wont lower it. Don't want to add anything that I do not need.

[CarlD]

Well, have you got metal in your water that you need to keep in suspension? (besides calcium--calcium's a metal)

[grangerhj]

I did get metal readings this spring when I took my well water to be tested by pool store. Since use well water to fill my pool, I have been adding metal magic every time I add water. The large brown stains on the side and bottom were clear when Vit C was applied so I have assumed that this meant that the stain was caused by metal and not algae. This is why I thought I should keep my ph at 7.2 Am I correct? ..... Or have I overthought something

[CarlD]

Maybe one of our metal-experts can help you--I'd only be guessing.

[mbar]

You only need to keep your ph at 7.2 if you are trying to lift the stain off, or are going to shock. If you have enough sequestering agent in the water, then it you won't get stain if your ph is 7.6. It is with a high ph and a high chlorine level that the metals fall out of suspension if there isn't some sequestering agent there to bind with the metals. As a precaution I always keep my ph no higher than 7.4, and if I have to shock I take it back to 7.0 - 7.2. So you are right - if you are going to shock, I would bring the ph back down to 7 or 7.2. If you have a sand or DE filter you can put a chlorine puck in the skimmer basket - even though you are battling high cya, it will still be a good idea if you are prone to stains. Just be sure if you add the tablet to your skimmer, you don't put the bleach in the skimmer too. Add it to the return jet stream. DO NOT put a puck in the skimmer if you have a cartridge filter. Hope this helps - ask any other questions you may have.