PH going up again!

[waterbear]

It is definitely testing error (or more likely, the normal variance from the precision of the test.) You numbers look like their are either from a strip reader or colorimeter. If they are from a strip readier they are just not to be trusted. If they are from a colorimeter such as the LmMotte Waterlink system they are in spec because, if my memory serves me correctly, the LaMotte UDV TA test has a precision of +10 ppm / - 20 ppm for a variance of 30 ppm. (The Taylor titration test, which does not use any fancy meters is actually ore precise with a precision of +/- 10 ppm!)

[Mr.Mooks]

Thanks Waterbear. Not sure what the test is but no strips are used. My water sample goes into about 6 if not more little clear vials with couloured lids on them. Then they are put 1 at a time into a little red box connected to a computer. After a few minutes they give me printed results. If I can get through this season this way I will purchase a taylor kit throughout the winter. With all the install and setup costs with the pool cash is tight. Thanks everyone for all your help. I will post test results ina few days after CYA have dissolved. Then again I will call on your guideance.

[waterbear]

Thanks Waterbear. Not sure what the test is but no strips are used. My water sample goes into about 6 if not more little clear vials with couloured lids on them. Then they are put 1 at a time into a little red box connected to a computer. After a few minutes they give me printed results.

Sounds like a LaMotte Waterlink Express. I know it well and am certified on it by LaMotte. It's good for pool stores since a whole batter of tests is done in 3 minutes BUT it does not have the precision of the Taylor kit and the type of variance you see in test results is common.

Bad new is the CYA and Calcium Hardness tests with this unit are even worse than the TA test with both of these being +10/-25 ppm! (This is a variance of 35 ppm which, for a CYA test is VERY significant!)

[Mr.Mooks]

Yes Waterbear I clicked on the link you provided and that is exactly the machine they use. Now without having a Taylor what do you suggest? Find a pool store that use a different method? Can I just walk in and ask them? If so what type of test should I be looking for? On the brighter side my CYA power is dissolving very well and with my own OTO kit the Ch seems to be holding better. But I do not have a test for my CYA so I am not sure what it is at currently. I do have strips but they never give me the same result twice.

[waterbear]

Yes Waterbear I clicked on the link you provided and that is exactly the machine they use. Now without having a Taylor what do you suggest? Find a pool store that use a different method? Can I just walk in and ask them? If so what type of test should I be looking for? On the brighter side my CYA power is dissolving very well and with my own OTO kit the Ch seems to be holding better. But I do not have a test for my CYA so I am not sure what it is at currently. I do have strips but they never give me the same result twice.

The water link is OK but just realize that the precision of the unit is less than a Taylor testing station (AND if the testing is not properly timed then the results can be off.) It is better than strips. AS to what kind of testing to look for I would say Taylor BUT many pool store employees are not really properly trained in water testing. You really should get your own kit. If you consider how much your pool and SWCG cost then the cost of a good test kit really isn't that much and, with what it will save you in chemicals and maintenance, will quickly pay for itself.