My CH vales vs Leslie's.

[Cajun]

Since doing the bbb method I have only gone to Leslie's for DE or pucks for when I'm out of town. When I go I always bring a sample of water just to see their numbers. They have always been inline with my readings.

My neighbors pool is not the same. I started helping with their pool around May and I have always found their CH to be 550-650 range. I have got all other ranges inline for them but this one. I told them to have Leslie's sample the water for a 2nd opinion. They took water to them twice about a month appart and got 200 and 250 for their CH. I'm kind of at a loss here. I'm wondering if I'm doing something wrong. Sometimes I think maybe I hit the fade point and the test is invalid others I'm not sure. But the sample will turn blue (not sure if that's normal if I hit the fade point or not). I am using a speedstir and have even tried adding few drops of R-0012 1st.

Any thoughts here?

 

[ping]

Try adding 90% of the expected amount of R-0012 before adding R-0010 or R-0011L. This will help with the fading end point and the test should turn blue and avoid the purple color. If the CH is 200 add 18 drops of R-0012 then continue the test as normal. If the CH is 550 you will need 50 drops of R-0012.

I'm not sure which one of you is wrong, but it is clear that someone is not getting the correct number. To save reagents you can test with 10ml of water instead of 25ml. Follow these instructions for that, extended-test-kit-directions-t25081.html. These instructions say to add a few drops of R-0012 first, but by using 90% of the total amount you need seems to help more with the fading end point.

 

[257WbyMag]

Are you using a Speed Stir during the CH test?

 

[Cajun]

Are you using a Speed Stir during the CH test?

Yes.

 

[Bama Rambler]

Re: My CH vaules vs Leslie's.

Even with the SpeedStir you need to let the sample mix for several seconds between drops. If you're dropping them pretty rapidly, it's easy to go over pretty far before it changes color. That's most likely not the case here.