Autopilot Salt ppm Calibration

[nupoolsoon]

Maybe I should post under my old thread, but they sometimes do not get picked up again.

When we had our SWG calibrated the salt was at 3400ppm. I just tested our salt this morning and it is still at 3400ppm..good thing I guess (Ph was at 7.5 and CL at 3.0). Although to be honest with you, we have not run the SWG all that much b/c for some reason, when we got back from vacation and I added more bleach to shock the pool, the CL levels remained steady at 6.0 for almost two weeks. I couldn't do that all summer long. Guess that shows how much "stuff" the landscapers were getting in the pool while working. The chlorine was just eating the organics up.

However, I really would like to get the salt levels down...the pool water is VERY salty (tasting). I know you are not supposed to drink the pool water...LOL.

How can I get my salt levels down yet still have the SWG add the needed chlorine? What would happen if I changed the calibration down to 3000ppm?

Thx.

 

[JasonLion]

If you want to lower your salt level you need to replace water. To lower salt from 3400 to 3000 requires replacing about 12% of your water.

Re-calibrating the SWG won't change the salt level, it will only change the salt level the SWG thinks there is.

The AutoPilot SWGs work with salt between 2500 and 3500, so lowering the salt level down to 3000 should be fine.

 

[smallpooldad]

We also have the Pool Pilot (Digital), SC-60, 10,000 gal at pH of 7.5, Calcium at 425, Alk at 80, CyA at 32, av temp 84, FC at 5, power setting 2.

Asked a question on the Poolforum site of Sean, the representative from AutoPilot, as to how much salt is the optimum as it states between 2500 and 3500. He stated 3500 is optimal as this keeps the unit cooler and the it will then last longer.

So we raised the pH to 3600, and noticed no difference in the taste of the water. Although we can taste the salt at both 3000 and 3600. It might be that you have better taste buds than us or that the calibration was not done correctly. The best way to know the true calibration is to do it yourself with a Taylor Industries SodiumChloride (salt water) test kit, number K-1766 (rather expensive at around $25), there may be other good drop test kits but I am not aware of them, others may wish to comment.

If the calibration was done by a pool store, or pool person there is a good chance it is incorrect, mine was that is why I purchased the kit.

If you did it yourself with a good test kit and not strips, then my apologies for this response, you obviously have better taste buds than us.

Here is a link about taste buds:

http://www.bbc.co.uk/science/humanbody/ ... ment.shtml

I think we are on the low end, it must be all that hot Indian, Korean a Thai food we eat.

But the unit is great, is it not? The service I have recieved from them has been excellent.

Aloha.

 

[JasonLion]

The AquaChek salt test strips are a better choice than the Taylor kit. The Taylor salt test kit is tricky to do right. Too many people seem to have problems with it for me to recommend it. The AquaChek strips are actually a reverse titration, a much better approach than the usual test strips.

The ability to taste low salt levels varies rather widely from person to person.

 

[smallpooldad]

JasonLion,

Thank you for you help.

I'm sure you are right but I am confused why do people find the Taylor test kit difficult to use, it simply changes color quickly in one drop?

Why is reverse titration better than the Taylor test, again I'm sure you are right, but could you explain why? What method is Taylor using and why is reverse titration better?

Why are most basic test strips not considered to be accurate yet this is, or is this incorrect?

If I purchase the test strips how long should I leave them in the water, its about 86 F in the pool and the air outside 80 F, not sure if that makes any difference.

Needless to say I am looking for a little education here.

Thank you in anticipation,

Aloha.

 

[JasonLion]

Standard test strips have a pad with embedded chemicals which react to produce a color which must be compared to a color standard. The amount of water taken up by the pad and the reaction time are both difficult to control and most people are not that good at color comparisons. At best the standard test strips have low precision, but often enough they are totally wrong.

The AquaChek salt test strip uses capillary action to draw a controlled amount of water into the reaction area. An indicator at the top changes color when the test is complete. This approach solves the two most common problems with standard test strips, and so is far more reliable than the usual test strip design and capable of reasonable precision. As long as the strips have been kept dry they are quite good.

The Taylor salt test can give incorrect results if drops are added too quickly or there is insufficient mixing of the sample as drops are added. If done properly the Taylor test has better precision than the AquaChek strips.

 

[smallpooldad]

Jason Lion,

Thank you for a great,clear, and polite answer.

Had to pick up my daughter who is home in Hawaii for the holidays and working a part-time job. On the way I stopped at the pool store and bought the Aquachek strips.

Just tried them out and if I am reading them correctly they do agree with the Taylor kit. The white part matches Taylor, there are a couple of bars above that are partially white but not fully, the sides are brown, so I did not count them.

My conclusion is that I prefer the Taylor kit, it seems I must be testing correctly, but for a "quick and dirty" the test strips are fine. Using both gets you a second opinion and as with any proposed medical procedure that is always good; so I learnt something new. In the future to make sure my reading is correct I will compare both.

As regards the increased taste of salt, my wife says she can notice the difference between 3000 and 3500, but as this is the only piece of my little world that I control 3500 ppm is what it will be. Victory at last, albeit a silent one, a very silent one.

Aloha.