- Aug 19, 2018
- 930
- Pool Size
- 23000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45
For many, many years I used a LaMotte test kit to check my chemistry. Uses a slide color comparator for FC, CC and pH. Tablets dissolved in the appropriate amount of pool water. Was running low on some of the less frequently used tabs, so made the jump to the TFP test kit.
They generally agreed well on most of the tests. And I love the better accuracy for FC/CC in the TFP kit. Plus the stirrer is fun to use. But, two items are an issue:
CYA - the LaMotte disappearing dot test consistently reads about 15 points below the TFP. I like having a CYA of 40 more than I like 55. Might take a sample to the pool store to settle the matter, but thought I would solicit opinions here, first.
PH - the increments in the TFP test of .3 is just bad. I have to guess whether it is closer to 7.2 or 7.5? The LaMotte does it in increments of .2 and is easier to interpolate to in between values. At least they seem to be in general agreement with each other, even if the margin of error is there. While I have a seasons worth of LaMotte tabs left, is it valid to come up with my own number of drops per ml of water brew to continue to use the Lamott comparator? Haven't measured yet, but it appears to need about twice the water, so may need twice the drops for use. Does the test scale properly?
(yeah, I got the meter too. And it is wonky like many others report...)
They generally agreed well on most of the tests. And I love the better accuracy for FC/CC in the TFP kit. Plus the stirrer is fun to use. But, two items are an issue:
CYA - the LaMotte disappearing dot test consistently reads about 15 points below the TFP. I like having a CYA of 40 more than I like 55. Might take a sample to the pool store to settle the matter, but thought I would solicit opinions here, first.
PH - the increments in the TFP test of .3 is just bad. I have to guess whether it is closer to 7.2 or 7.5? The LaMotte does it in increments of .2 and is easier to interpolate to in between values. At least they seem to be in general agreement with each other, even if the margin of error is there. While I have a seasons worth of LaMotte tabs left, is it valid to come up with my own number of drops per ml of water brew to continue to use the Lamott comparator? Haven't measured yet, but it appears to need about twice the water, so may need twice the drops for use. Does the test scale properly?
(yeah, I got the meter too. And it is wonky like many others report...)