Does Leslie's test the CYA? (2024)

Welcome to TFP!!!

Usually most pool stores will test CYA ... BUT ... that happens to be the parameter they are the WORST at getting right.

In general, we do not trust pool store testing at all.

The fact that they do not even list it on the sheet just confirms how little that particular store must understand pool chemistry.

They may not be any better. If you filled the pool and used poolmath to calculate How much stabilizer to add I wouldn’t worry to much about it since it is a small pool.

Assume you are correct and use that cya number on the chart and keep the proper amount of FC in the pool.

If you do go to that pool store ask how they test cya. If they actually use a test tube ideally they should go outside with there back to the sun to read for the dot at the bottom.

Curb71 said:

For the last week I've been cleaning the filter and running the pump 24/7. Every day or two I check the chemicals and it's always about 8.2pH and about .5ppm of chlorine. I add what the pool calc says to add and the next day or 2 it's right back to the same. Does this mean the CYA is off or something else? I understand the chlorine will naturally go down and I need to add more but is it normal for the pH to always go up? Should the chlorine be virtually gone within 24-48 hours?

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With the high TA, and the probably higher TA fill water you use to top off, pH is going to climb rapidly. Also, if you're reading 8.2, it could be 8.5 or 8.8. You don't know. You can't know -- that's as high as the tester reads. You may have been bringing it down .1 at a time and you just haven't gotten into range. Or you bought the weaker (yet full-priced) safe or low-fume muriatic acid so you aren't seeing the pH drop poolmath says you should be getting.

As for chlorine loss, a perfect pool with no swimmers is still going to lose about 2 FC per day. Low CYA or a lot of swimmers and a lot of sun and you could easily burn through 4 FC per day.

Richard320 said:

With the high TA, and the probably higher TA fill water you use to top off, pH is going to climb rapidly. Also, if you're reading 8.2, it could be 8.5 or 8.8. You don't know. You can't know -- that's as high as the tester reads. You may have been bringing it down .1 at a time and you just haven't gotten into range. Or you bought the weaker (yet full-priced) safe or low-fume muriatic acid so you aren't seeing the pH drop poolmath says you should be getting.

As for chlorine loss, a perfect pool with no swimmers is still going to lose about 2 FC per day. Low CYA or a lot of swimmers and a lot of sun and you could easily burn through 4 FC per day.

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I haven't added any water since I filled the pool. This is the testing kit I have. The color from the test looks identical to the 8.2 color so I assume unless it doesn't actually get more pink if it's higher, than it is actually 8.2, or pretty close. This is the pH down I use.

zea3 said:

pH is going to rise more easily with high TA. If the water from the return churns the surface of the pool it will make the pH rise. Lots of splashing will also make the pH rise. Just keep adding MA and you will get the pH to stabilize. What are you targeting as your FC level? You should be raising it up to 7 ppm and not let it drop below 5 ppm.

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7 ppm!!? Everything else I read said to raise it to 4. So that's what I've been doing and it seems a day or two later there's very little if any chlorine left. The water from the return DOES churn the surface. No splashing going on and not lots of people. I'll bump my goal for chlorine to 7 ppm.

For a pool with 40ppm of CYA and no SWG your target level is 5-7. You always want to shoot for the top of your target level, so when you get that 2ppm drop over the day you don't drop below your minimum of 3ppm. If you are shooting for 4ppm as your target then when you have that 2ppm drop you are below the safe minimum level and algae can get a foothold.
Non-SWCG Pools