Doing alkalinity test with smaller water sample - How to know correct multiplication factor to arrive at accurate ppm reading?

[Icicle278]

To preface... I have the Poolmaster 22260 test kit. I have never been able to get a color change when following the alkalinity test kit instructions, which by my measurement uses a 15ml water sample. Even after 20+ drops, nothing would ever happen. Taking the advice of TFP community via an earlier thread, I tested using a 10ml sample instead. Now, I need to test my assumptions on the correct calculation here. Using the 15ml sample, I am directed to multiply number of drops by 10 to determine the ppm. With the modified 10ml water sample, am I correct to multiply the number of drops by 15 to determine the ppm? By that math I calculated approximately 180 ppm from 12 drops. If that is correct, then I'm confused why the color didnt change with 18 drops using the standard 15ml sample.

 

[Bperry]

To preface... I have the Poolmaster 22260 test kit. I have never been able to get a color change when following the alkalinity test kit instructions, which by my measurement uses a 15ml water sample. Even after 20+ drops, nothing would ever happen. Taking the advice of TFP community via an earlier thread, I tested using a 10ml sample instead. Now, I need to test my assumptions on the correct calculation here. Using the 15ml sample, I am directed to multiply number of drops by 10 to determine the ppm. With the modified 10ml water sample, am I correct to multiply the number of drops by 15 to determine the ppm? By that math I calculated approximately 180 ppm from 12 drops. If that is correct, then I'm confused why the color didnt change with 18 drops using the standard 15ml sample.

Usually when scaling drop style tests, you also need to alter the drops of reagent and dye used, not just the water sample. (At least on the Taylor kits). Is that what you’re doing? TFP doesn’t recommend anything other than Taylor kits so I’m not familiar with Poolmaster. Here’s a bump for you in case someone else is familiar.

 

[mknauss]

The vial used for that kit is marked for the level you are to use for the water sample. Then the instructions clearly show how to perform the test.

Are you modifying the test procedure?

 

[Icicle278]

I was attempting to follow the same logic as was recommended by the TFP community for scaling down the Taylor tests using smaller water samples. The instructions for the poolmaster test kit do not touch upon how to perform tests using smaller water samples.

 

[mknauss]

With the reagents used in the Poolmaster, not sure if that would work.

 

[Icicle278]

With the reagents used in the Poolmaster, not sure if that would work.

Any thoughts as to why the Poolmaster reagents would behave differently than the Taylor? They appear to be similar and highly rated kits and seem to involve essentially the same procedures just using different sized water samples and perhaps slightly different colors for the reagents.

 

[Bperry]

Any thoughts as to why the Poolmaster reagents would behave differently than the Taylor? They appear to be similar and highly rated kits and seem to involve essentially the same procedures just using different sized water samples and perhaps slightly different colors for the reagents.

They may not behave differently, as the Taylor kits require more than just changing the water sample size. Since we don’t know what reagents poolmaster uses and in what quantity, we can to ow for sure. Have you tried investing in a TF-100? It’s really worth it. I have a rainbow kit still sitting around I haven’t touched in a long time.

 

[mknauss]

Any thoughts as to why the Poolmaster reagents would behave differently than the Taylor? They appear to be similar and highly rated kits and seem to involve essentially the same procedures just using different sized water samples and perhaps slightly different colors for the reagents.

Ask them.

 

[magiteck]

Any thoughts as to why the Poolmaster reagents would behave differently than the Taylor? They appear to be similar and highly rated kits and seem to involve essentially the same procedures just using different sized water samples and perhaps slightly different colors for the reagents.

Ask them.

Contact Us – Poolmaster

Customer Service
For Consumers: 1-800-854-1492
For Dealers: 1-800-854-1776
Phone: 916-567-9800
Fax: 916-567-9880

Hours of Operation
Monday – Friday
8:00 am – 4:30 pm (PST)

 

[Icicle278]

They may not behave differently, as the Taylor kits require more than just changing the water sample size. Since we don’t know what reagents poolmaster uses and in what quantity, we can to ow for sure. Have you tried investing in a TF-100? It’s really worth it. I have a rainbow kit still sitting around I haven’t touched in a long time.

I dont think the TF-100 kit is still offered. Seems like Taylor offers the K-2005 / 2006 these days

 

[mknauss]

TFTestkits.net is whom offers the TF100 -- TFTestkits.net

 

[Icicle278]

Got it, makes more sense now. Thanks for the link!

Before I go upgrading test kits (as I don't think a subpar test kit is really the problem here) I will try to get feedback from PoolMaster as to what else might be involved in adjusting my water sample size for the Alkalinity test.

 

[magiteck]

Got it, makes more sense now. Thanks for the link!

Before I go upgrading test kits (as I don't think a subpar test kit is really the problem here) I will try to get feedback from PoolMaster as to what else might be involved in adjusting my water sample size for the Alkalinity test.

Keep in mind, even the Poolmaster “deluxe kit” doesn’t include a CYA test, which is one of the most important levels.

It also doesn’t include an FAS-DPD chlorine test, so you’re unable to accurately test for higher levels of FC.

So even if you determine you are satisfied with the other components of your test kit, you should look into adding a Taylor K-1515 for chlorine and a Taylor K-1721 for CYA.

By the time you do that though you’d come out ahead value-wise by just getting the TF-100 (or Taylor K-2006C) — and then you’d have all the tests that the experts here can accurately give advice on.

Test Kits Compared

 

[Icicle278]

Thank you for the recommendation, and you are likely right that there is value in having the all-in-one test kit. Perhaps this is just pure luck, but I was able to get through all of last summer with pretty stable weekly chemical readings once the pool was up and running with the SWG, without needing to measure CYA or FC. Might be flawed thinking to expect that trend to carry over year to year though.

 

[Bperry]

Thank you for the recommendation, and you are likely right that there is value in having the all-in-one test kit. Perhaps this is just pure luck, but I was able to get through all of last summer with pretty stable weekly chemical readings once the pool was up and running with the SWG, without needing to measure CYA or FC. Might be flawed thinking to expect that trend to carry over year to year though.

If you aren’t testing chlorine or CYA, almost a guarantee you’re going to have a surprise on your hands.