One week ago my alkalinity was 200 so we put in muriatic acid. Well, we added it gradually over 2 days but didn't know to check the pH. So of course, we got extremely low pH and then lots of algae. We have shocked it over 3 nights and finally it looks like the algae is gone but the water is still really cloudy. This morning Free Chlorine is around 30, pH is 8.0 and alkalinity is 110. I know I need to lower pH but don't want the alkalinity to go below 100. I feel like it's a yo-yo effect going on. What should I do?
help with getting water cleared up
- Thread starter kymom73
- Start date
How are you testing the pool water?
pH testing is unreliable when the FC (free chlorine) is above 10 ppm. It will often read higher than it actually is.
Algae did not take hold because of low pH, it's because of inadequate chlorine levels. The necessary free chlorine level is determined by your CYA (stabilizer) concentration. Do you have a test kit capable of testing CYA? See Pool School - Test Kits Compared The TF-100 is the best available for the price with the K-2006 being a close second.
Check out ABCs of Pool Water Chemistry for some background on pool water chemistry and the basics of getting started. You can also check out the CYA/Chlorine chart and the SLAM procedure in my signature because that procedure is what your pool needs to get clear, not just shocking. Shocking with powder products can also raise your CYA, which can make the process more difficult. Liquid chlorine, aka bleach, is what is needed.
pH testing is unreliable when the FC (free chlorine) is above 10 ppm. It will often read higher than it actually is.
Algae did not take hold because of low pH, it's because of inadequate chlorine levels. The necessary free chlorine level is determined by your CYA (stabilizer) concentration. Do you have a test kit capable of testing CYA? See Pool School - Test Kits Compared The TF-100 is the best available for the price with the K-2006 being a close second.
Check out ABCs of Pool Water Chemistry for some background on pool water chemistry and the basics of getting started. You can also check out the CYA/Chlorine chart and the SLAM procedure in my signature because that procedure is what your pool needs to get clear, not just shocking. Shocking with powder products can also raise your CYA, which can make the process more difficult. Liquid chlorine, aka bleach, is what is needed.
You should tell us HOW you are testing and give us your CYA number. Any KNOWN reason your TA shouldn't go below 100? My PH is a lot happier in a vinyl pool with TA at 60 for instance. Keep filtering and backwashing to remove the dead algae. Have you passed the OCLT?
Tested with Taylor K-2005. I know my CYA is at least 100 because of using the trichlor which we have stopped using a couple months ago. We are going to be draining partially when we close in a week and that will take care of that. I don't want to drain and refill only to drain again in a week. I did use liquid for shocking. Pool calculator said to add 19 oz muriatic acid to bring pH down. Should I do this?
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I read everywhere TA should be 100 so that's what I thought. I did backwash twice, second time the water was clean and clear coming out. What is OCLT?
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I read everywhere TA should be 100 so that's what I thought. I did backwash twice, second time the water was clean and clear coming out. What is OCLT?
As was noted above, the pH test is inaccurate to the high side any time FC is above 10. I would hold off on the acid until you can see where you are, especially as the limit of chlorine with the K-2005 is 10ppm.
I would consider picking up the individual FAS-DPD chlorine test which will essentially turn your K-2005 into a K-2006.
What is your water temperature? We generally advise holding off closing until the water is below 60. The lower the better. Algae growth is retarded in cold water, so if you can close with cold clear water and open next year before the water gets above 60 it will make your life easier. While following this,late close/early open schedule means you will be maintaining a cold unswimable pool, it also means you generally won't have much algae to deal with when you open.
As to reading that TA should be above 100, there are hundreds of recommendations in the pool industry. Ours is based on the experience of tens of thousands of member pool owners. I would just caution you to pick a single source for pool maintence information and stick with it. Trying to mix TFP advice and that from other sites and pool stores is going to be frustrating at best and impossible at worst.
I would consider picking up the individual FAS-DPD chlorine test which will essentially turn your K-2005 into a K-2006.
What is your water temperature? We generally advise holding off closing until the water is below 60. The lower the better. Algae growth is retarded in cold water, so if you can close with cold clear water and open next year before the water gets above 60 it will make your life easier. While following this,late close/early open schedule means you will be maintaining a cold unswimable pool, it also means you generally won't have much algae to deal with when you open.
As to reading that TA should be above 100, there are hundreds of recommendations in the pool industry. Ours is based on the experience of tens of thousands of member pool owners. I would just caution you to pick a single source for pool maintence information and stick with it. Trying to mix TFP advice and that from other sites and pool stores is going to be frustrating at best and impossible at worst.
Welcome to the forum.
As mentioned, algae (& bacteria) growth is due to lack of sanitizer. Your FC levels have certainly gone below what is needed to sanitize the water.
With pH & Alkalinity, pH is king. Focus on getting pH into the 7.4-7.6 range, and that it remains stable. TA will find a happy place and the two will learn to play nice together. Do you have any water features that would aerate the water?
How did your TA get so high in the first place? Were you battling low pH?
A FC of 30ppm is very high unless you have a higher CYA level. A guess here is just not good enough.
Please have a read through Pool School, especially The ABC's of Pool Water Chemistry, Pool Chemistry, & How To SLAM (Shock Level, And Maintain).
We do not advocate dumping a random amount of anything into a pool here. TFPC is based on only adding what the pool needs based on accurate and frequent testing.
We can help if you are willing to be open minded to how simple pool care can really be.
Dom
I don't know how the TA got so high. PH came up and was perfect after I stopped using the trichlor tabs. Water was cloudy and TA was 210 so I thought it needed to be at 100 based on my test kit recommendations.
The recommended TA here at TFP is 80-100 ppm for a manually chlorinated pool. TA is one of the last things to worry about for pool chemistry. TA level simply determines your pool's ability to buffer pH changes, determines how fast your pH will rise with aeration. Simply maintaining proper pH will eventually settle your TA into a "happy place". The recommended levels are just that, recommendations. If you get low pH rise at 120 ppm, great. If you get low pH rise at 70 ppm, great. I'd only be concerned with adjusting TA if it dropped below 60 ppm.
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