CYA level and chlorine level and pool store recomendation

[Fishcrazy]

I appreciate the help. I have been using test strips to get some readings when I could not get to the pool store but I have come to think that I need my own test kit to stay on top of this. First off I am not so sure of these test strips and their precision and secondly Im not so sure of the pool store's precision either! Case in point. My strips would not test for CYA and the pool store test result of 60 is not the same as my recently acquired test kit result of CYA = 35. I ran the test twice to make sure that it was right. I look down through the top of the tube at the dot till it totally disappears? Or can you look at the dot through the side of the tube? I read it from the top. Is this black dot test the same one that comes in the kit? Im going to test it again to see if it is correct.

My pool is situated under some shade trees and only gets direct sun around noon for a couple of hours. I do have to keep after the leaves constantly because of this. Every day the skimmer will be full practacly to the point of cloging up the circulation system and then again during the day. I suppose that I will need to cover the pool if I have to leave for any period of time for fear that the leaves will choke off the circulation all together. Any suggestions would be welcome on this problem.

My pool seems to hold its chlorine well. I put a couple of pucks in the other day and the FC level went up to 5 ppm. It seems that when I have added chlorine in the past the level maintains itself for a week. It surprised me to see the FC up to 5 from the two pucks but I guess Im getting to a level of chlorine that is telling me that I need to test more frequently to figure out what level of addition I need to make in chlorine on a regular schedule to maintain the required amount of chlorine. The strange thing about the Best Guess table to me is that there is a higher level of FC required with a higher level of stabilizer. Im sure I dont understand the chemistry but it seems intuitive that if you add stabalizer to make the chlorine more effective then why does more stabalizer cause one to require more FC? I would think that more would require a lesser FC due to the stabilizer effect of protecting the chlorine from being burned off by the sun. Im not thinking about this right, am I?

Im off to check the CYA again and the test strip method for the other readings. Can you recommend a test kit that would complement the one I have or do I just have to end up with 2 CYA tests? Thanks for all the help!

[aylad]

You are right to question the accuracy of the test strips...around here we call them "guess strips" and don't rely on them at all, because they are neither accurate or precise. They are good for telling you if there IS chlorine or if there ISN'T chlorine (sometimes), but don't depend on them for regular maintenance testing.

Sounds like you're doing the CYA test correctly--you view the tube from the top, holding it at waist level, and put the solution (reagent mixed with pool water, shaken VERY well) in until you can't see the black dot. It doesn't surprise me that your test result is different from the pool store--and I would go with yours.

The test kit that we normally recommend is the K-2006, which can be found at the Amazon link in my sig (anything that is purchased through this link results in a small donation to PoolForum, too). If you already have a kit that uses drops to test for pH, TA, CH, and the reagent test for CYA, then you can just add the K-1515 at the same page, which is just the chlorine test that uses powder and a drop system, and is capable of measuring accurately up to 50 ppm, as well as measuring CC.

I'll let the chemists explain why the chlorine levels need to be higher with the CYA being higher, but the bottom line is that as your CYA rises, so must your baseline chlorine. And yes, you do need to test chlorine at least daily to make sure that you're maintaining the required level to keep the pool from going green on you. Remember that the pucks are adding stabilizer, so if you continue to use those, you'll need to test for CYA occasionally, too. Not everyday, but I would say at least weekly or so if you're using the pucks on a regular basis.

Janet