Setting a Benchmark for Salt Test - Quantities of Mix

[smallpooldad]

Yesterday I posted a question on the accuracy of Aquachek pool strips, versus pool unit and the Taylor salt kit.

Thinking about this overnight I came to realize there might be a way of confirming the accuracy of the strips and Taylor salt kit but I do not know how to this. However I think I understand the principal but not what quantities are involved and this is where I need help.

For a given amount of water and a given amount of salt mixed together it should be possible to create a test solution that gives say 3500 ppm of salt, against this base liquid I could then use my test strips and Taylor kit to see if they are functioning correctly.

By my calculation 2.22 gallons of water which has a starting pH of 7.8 and an alkalinity of 80 (with no calcium, CyA or borax), added to 1 oz of salt should register 3500 ppm, but I am not sure if this is correct.

Or perhaps better still is there a test solution one could purchase?

Help would be appreciated.

Aloha.

 

[duraleigh]

Deep End, please.

 

[JasonLion]

The problem with this approach is that you probably can't measure 1 oz of salt accurately enough to be useful without a laboratory scale, and that is just one of your sources of error. There are a number of possible sources of error in making up the reference solution, which add up to imprecise results fairly quickly.

Also, I calculate that 1 oz of salt in 2.2 gallons of distilled water gives a salt level of 3,400.

Goldline sells a salt calibration solution, GLX-CAL-SOL, which goes for $12-$15.

 

[smallpooldad]

JasonLion,

Thank you once again for your reply and information.

As luck would have it I have a friend who has lab scales, but I agree that a purchased solution would be far better.

Aloha.

 

[Guest]

If you want to test the accuracy you should do it against a properly calibated meter such as the Goldline or MyronL salt meters... I have done so and am very satisfied with the precision of the Aquachek salt titrators. The Taylor chromate/silver nitrates titration can be very accurate if done properly but it is one of the more difficult titrantions to DO properly. It has a precision of +/- 200 ppm, btw. The Aquachek strips have a variable precision which depends on the acutal salt concentration. At higher levels of salt they are less precise but at higher levels of salt the errors becomes less critical.

 

[smallpooldad]

Waterbear,

Thank you for your reply. My own observations completely validate what you have written. The AquaChek Strip is accurate to within 200 ppm, as is the Taylor kit. But as you mentioned it needs more time to do properly although now that I know that it should be done slowly I prefer it. You are also correct in that the AutoPilot Digital Salt reading needs to be set manually from the AquaChek or Taylor reading, even their tech support stated this to me.

Than you for your help.

Aloha.