rrgone Posted June 1, 2012 Report Share Posted June 1, 2012 Hi, About 2 weeks ago I went out to get the pool water ready for the summer. It's been hot here in S AZ but we haven't had a chance to use the pool yet. I kept chlorine tabs in the floating dispenser all winter. I took a sample and noted very high chlorine. pH was somewhat low and Alk was about 200. I took the floating chlorine dispenser out of pool and adjusted pH and Alk. They are pretty good now, 7.4 pH and about 140 Alk, but I need to go get some more muriatic acid to reduce Alk some more. But chlorine is still way high. It's been 2 weeks now and chlorine is still off scale above 5. I have a Leslie's DPD test kit, about 20Kgal inground pebble tec pool. I was sure that this sun would burn the chlorine out but it's as though chlorine is still being added. What is going on? Thanks. Quote Link to comment Share on other sites More sharing options...
chem geek Posted June 1, 2012 Report Share Posted June 1, 2012 Your Cyanuric Acid (CYA) level is probably very high which is significantly slowing down the rate of chlorine loss. Also, your chlorine level may be very high. If you get a FAS-DPD chlorine test (the K-2006 for the complete kit including CYA or the K-1515 for just the FAS-DPD chlorine test), you'll be able to know how high. In the meantime, you can try diluting the pool water with distilled or filtered water and using your DPD test for an estimate. If your CYA is very high, then as the FC level drops you risk getting algae in the pool. Get your CYA level measured and if it's substantially over 80 ppm, then I suggest a partial drain/refill to lower it. You actually don't want the FC to get too low if your CYA is very high. If the CYA were 200 ppm, then even 20 ppm FC would not be too high. Quote Link to comment Share on other sites More sharing options...
rrgone Posted June 1, 2012 Author Report Share Posted June 1, 2012 Thanks for reply. I will try to get CYA level tested today. How did it get so high do you think? I drained the pool year before last and put in fresh water. Is it just from using the Leslie's 3" stabilized tabs for two years that It got excessive? Water is too expensive down here to throw away every two years.... Quote Link to comment Share on other sites More sharing options...
PoolGuyNJ Posted June 2, 2012 Report Share Posted June 2, 2012 Tablets add CYA. The only way to get rid of it is via dilution since there are no reverse osmosis services by you that I know of. You will likely need to drain some of the the pool water and add fresh water. Scott Quote Link to comment Share on other sites More sharing options...
PaulR Posted June 2, 2012 Report Share Posted June 2, 2012 According to poolcalculator.com, in a 20K gallon pool, each 8-oz tab will add about FC 2.7 and CYA 1.7. Just to give you some idea. Of course the chlorine gets used up over time, but the CYA really doesn't. (I bought a bucket of Leslie's tabs when I moved in where I am now; I didn't realize it would be a lifetime supply!) --paulr Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.