Ongoing High CYA Readings

[foxwlww]

We are new to the forum and are very frustrated with the pool store at this point. Over the last three years, we have gotten into a severe issue with high chlorine demand and extremely high CYA levels. We were barely able to use the pool over the past two summers and have spent ridiculous amounts of money on chemicals to no avail. When we opened this year, we had purple residue on the walls of the pool and the under side of our winter cover. Based on prior recommendations, we drained the pool halfway. We dry vacuumed the purple residue from the pool walls with a shop vac and vacuumed out the purple debris in the pool to waste. We refilled with city water. After refilling, we are still getting CYA readings of around 100 ppm. Does that seem possible? And if so, does that mean we need to drain the pool halfway again before doing anything else? We are strongly considering switching to the BBB method this year.

 

[Azgirl71]

Welcome to TFP! What test are you using to test your water?

the only way to lower CYA is partial drains and refills.

 

[AimeeH]

First, welcome to TFP

Second, how are you testing the CYA? Getting your own quality test kit is a priority. There is a link in my signature to the test kit I would recommend.

 

[foxwlww]

Thanks, we are using an HTH 6 way liquid test kit with the cyanuric acid reagent test vials. We performed the test twice and achieved about the same reading both times. We drained the pool half way after opening and then refilled with city water and still have the high CYA reading.

 

[Saturn94]

First, welcome to TFP

Second, how are you testing the CYA? Getting your own quality test kit is a priority. There is a link in my signature to the test kit I would recommend.

+1

This is priority #1 IMO. Without it there's no hope of taking control of your pool.

 

[Azgirl71]

As previously mentioned. You should invest in a recommended test kit. Strips are not reliable. You can do another partial drain and refill. That is the only way to lower CYA.

 

[foxwlww]

Thanks. We did purchase the recommended test kit, it is on the way. However, we are not sing test strips, we have the liquid test kit that uses the cyanuric acid reagent, and we performed the test twice. It would appear that the only option is to do another partial drain and refill???

 

[Beens]

Yes. Keep doing your drain and refill cycle until you can break that 100 number. Once you are below 100 you can use pool math (the calculator on this site - link at top of page) to tell you exactly how much more you need to drain to lower to your final target CYA.

When the CYA tests as 100 or more it could be well over that. It's definitely not unheard of especially if you have been following the pool store methods for years. Make sure you do not add any more chlorine products that have CYA in them. Dichlor powder and the chlorine tablets both add CYA.

Right now, Liquid Chlorine (aka bleach) is your best friend. It will add the needed chlorine without any CYA.

*edit*

Here's the link for Pool Math. http://www.troublefreepool.com/calc.html

Until you can get below 100 it's pretty hard/impossible to know exactly what the CYA level is so keep on keepin' on with the partial drain/refills until you get there.

Moderators/Experts, would the diluted test be appropriate here and is anyone familiar enough with the HTH 6-way to know if that CYA test can be run with the diluted method?

 

[Divin Dave]

CYA can only be tested reliably up to 100. Its defintely possible for your CYA to be actually way above that, which is why after your 50% drain and refill, you still see CYA of 100.

Unfortunately, you've been pool stored and we see this same situation multiple times from different folks every single day.

Sadly, the only remedy you have is to do another drain and refill as many times as necessary in order to get your CYA to a manageable level.
Once you do that though, and armed with the knowledge of TFP which is based upon science and not sales pitch an bs like the pool store, you will never have to deal with this situation again. And you will find that maintaining a Troublefree and Algaefree pool is quite easy and inexpensive to boot.

Thanks. We did purchase the recommended test kit, it is on the way. However, we are not sing test strips, we have the liquid test kit that uses the cyanuric acid reagent, and we performed the test twice. It would appear that the only option is to do another partial drain and refill???

 

[AimeeH]

There are instructions in this thread http://www.troublefreepool.com/threads/24188-Extended-Test-Kit-Directions
For diluting a test for when CYA is over 90. That may help you get a clearer picture of where your CYA is.

 

[pooldv]

Yes, it is possible that your CYA is still over 100, we've seen plenty of people with CYA of 300 or 400.