Ok, I'll switch to bleach. How do I lower TA? Muriatic acid? How much?
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Ok, I'll switch to bleach. How do I lower TA? Muriatic acid? How much?
Please read the following links. I think they will answer your questions.
Lowering Alkalinity Step-by-Step
Using Muriatic Acid Safely
A little more help needed, please.
Today @ 11am: FC=5.5, pH=8, CYA=55, TA=75, CH=450. FC has been holding steady @ 4-6 by adding 182oz. bleach daily.
I have been adding cyanuric to raise CYA to target of 80. Last addition was 4 lbs. on 6/28. Readings went from 35 on 6/27, 60 on 6/29, 70 on 7/2, 70 on 7/3, 60 on 7/4, 55 on 7/5.
Am I doing the test wrong? I know it shouldn't drop. I have not backwashed. Added about 3-4 inches of water that disappeared very quickly. Suspect I may have a leak near surface. I have also been adding muriatic acid & aerating to lower pH & CH. pH has been @ 7.3-7.6 but I ran out of muriatic & it went up to 7.8-8.
CH went from 500 on 6/28, 450 on 6/29, 400 on 7/1, 500 on 7/2, 450 on 7/3, 400 on 7/4, 450 on 7/5. I am using the 10ml. size test. It seems like the color starts to turn purple-ish at about 15 drops, but doesn't turn blue until 16-18 drops? Again, am I doing it wrong? I know I need to add more muriatic & cyanuric. What else do you recommend? I have set my targets at FC=5-10, pH=7.4-7.8 (after CH goes down), CYA=80-90, CH=200-400, TA=80. Are these reasonable targets?
Your target numbers look fine.
Don't run the CYA test so often. Also, after your addition of CYA on 6/27, your numbers all range from 55-70. This test is so subjective that you can't pinpoint an exact value, so getting these results doesn't necessarily mean you are losing CYA. They are all within the range. I wouldn't worry about it. Since it has been a week since you added CYA, go ahead and add more if your target is 80-90 but then don't run the test for a week or so. You're going to use up all your reagent if you test so frequently.
Run a CH, pH and TA reading on your fill water. (If you've already been asked to do this and have the results, post them. I didn't want to take the time to reread the whole thread.)
Use some more muriatic acid to lower the pH.
What all are you adding to the pool? (Ingredients, not just product names.)
Fill water results: Ch=125, TA=100, pH=8.0 (or above).
I am using 6% bleach, muriatic/Baume Hydrochloric acid 31.45%, HTH cyanuric acid 96%. Nothing else. I added 1 gal. muriatic & 4 lb. cyanuric last night.
OK. Keep working on the pH. Stick with bleach for your chlorine. And, don't retest your CYA for a week.
I have a question about CH. I have been trying to lower my CH from 500 since 6/27 by adding muriatic & aerating with fountain. CH went down to 400 but won't go any lower. TA went from 100 down to 50. I have added cyanuric periodically to raise my CYA to 75. I have used only bleach since 6/27. I use approx. 182 oz. 6% bleach/day to keep my FC about 5-7. pH has ranged from 7.1 (right after addition of muriatic) to 7.8. Pool is sparkling clean. Filter hardly ever needs backwashing now. Should I be worried about the high CH?
Aeration + muriatic lowers carbonate alkalinity; it has no effect on calcium levels.
As far as I know, the only two practical ways to lower CH (or TH) are by
(1) draining and refilling -- and this only works if your fill water is soft!
(2) lime softening to precipitate the calcium and then vacuum or filter it out.
You can see if lime softening will work for you, using the calcium bucket test:
http://www.poolforum.com/pf2/showthread.php?16992
If it was my pool and I had sparkling water, I probably wouldn't worry about CH of 400. That's not super high. In fact, the suggested level is 200-400. But, I would not use any cal-hypo and I would not let my TA and pH get high. Just my opinion.
(Note to others reading --- vinyl pools do not need calcium 200-400.)
Thanks.
I had come to the same conclusion- that 400 was not too high to worry about. My CYA is 75 & I'm using about 182 oz. of bleach a day, sometimes a bit more (364 oz.). I have been thinking of raising the CYA a bit higher (85-90) to hopefully use less bleach as you had suggested a while back, since my pool gets full sun all day.
What do you think?