taylor 2006 kit or test strips?

[THE DUDE]

Just a ramble and well since i had time, I took my water and another tubs water for testing. I pretty much knew what mine read as i test every few days with my 2006, log it and actually the day before and right after coming back from these tests. Not even close. Both tubs read the same ph 6.8, alk 40 and 0 FC from their test. I hit the other tub with 4 oz of liquid 12.5% the night before.

My tub was at 1.5 FC, 80 alky and 7.6 ph  with my 2006

other tub was at 2 FC , 50 Alky and 7.4 ph. with my 2006. I raised the ta and ph a few weeks ago since it was at 40 and 7.0 and brought it to 50 and 7.4.

They don't test for CYA but  do a TDS  and I don't believe it either. On the other tub, they said someone must have just changed the water because it was 400 and mine was 800.  Nope.

I asked what they use exactly and they said test strips and their computer. Kinda weird as it took them a while and they came back and apologized for the time it took because they had computer issues. On a test strip, I have my ph does look around 7.0 -6.8 area but the 2006 kit read 7.6-7.7 and takes 1 drop of acid to match the it to 7.4.  I told them I use the 2006 and wanted to double check readings. They suggested I have bad or old reagents.

I was surprised they both came out basically the same on both store tests and that's what prompted me to actually asked how they came up the results. Its a free test, i get it to a point, but i would rather give up a couple bucks for a test that's accurate. I'm not trying to knock them, they are supposed to be the experts and do more testing than i do,but I'm a little disappointed as if i would add what they wanted me to I believe  I would have thrown off the water balance.

 

 

[waterbear]

Pool stores need fast tests and the software they use is set up to maximize product sales. Strip readers still depend on strips which, while they will produce results that are repeatable on multiple tests on the same sample (precise results), don't necessarily produce results that are close to the true value (accurate  results). Several of the tests on strips are time dependent and if not read at the right moment will produce off results. Personally, I have found that strips tend to read low on pH and if you look at the precision for alkalinity is it often +/- 40 ppm which is useless for balancing water and the hardness test is for total hardness, not calcium hardness (a limitation of what can be tested by strips) and once again, a useless test for water balancing, ,IMHO.

1 hour ago, THE DUDE said:

They don't test for CYA but  do a TDS

Not testing for CYA is not surprising. That way they can continue to sell you dichlor even thought the tub is overstabilized. It is a fact that the higher the CYA the higher you need to run FC to achieve the same level of sanitation and oxidation. This has been known since the 1960s but has been suppressed by the industry, especially companies that produce stabilized chlorine, since it would cut into their bottom line.

As far as TDS, it's a bogus measurement to explain why there is a sanitation breakdown because of 'old water' instead of blaming it on high CYA. IF TDS actually was a problem then every salt pool or spa would not work and would have major problems from the moment the salt is added.

Interesting fact, the 'cure' for high TDS is exactly the same as for high CYA, a partial or complete drain and refill.