Aquarite salt readings keep falling although salt level is correct.

[Jocko]

I am having problems with both my Hayward AquaRite 940 Chlorinators which are 2 years 4 months old. From the installation of these chlorinators I have needed to clean them every 2 months or so. However for the last 6 months the cleaning frequency has increased regularly, so much so that for the last 3 months or so I need to clean them weekly because the salt readings drop by 100 ppm every day or every other day. I clean the cells thoroughly but after cleaning the readings are the same as my digital tester but fall from 3,200 to 2,700 in around 7 days so the process begins again. This is now unacceptable and very inconvenient.
I have adjusted the output from 50% all the way up to 100% but the same problem exists, all that happens is that the readings fall quicker with a higher output setting. I had Astral Pool Clorinators previously and they gave me no problems, the cells lasted 6&7 years before replacing. I do hope you can help? Thank You.

 

[Texas Splash]

Welcome to TFP! When a cell begins to show signs of inconsistant readings, two things come to mind. Either an old/bad cell, or the cell is compromised from poor water chemistry. You seem to be an experienced SWG owner, but we'd like to rule out water chemistry before assuming your fairly new cell is bad. So let's start with some questions for you:

- How you are testing the water? Which test kit?
- Can you post a full set of water test results?
- Have you been finding scale on the cell plates?

 

[Mdragger88]

Cleaning the cells with acid reduces their life as it removes the coating that helps produce the chlorine. It is likely yours may be depleted at this point due to the frequent cleaning.
It is recommended to keep your csi neutral to slightly negative to prevent the need to clean them with acid at all.

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.

www.google.com

Their rated life span is around 8k hours @100% output.
How large is your pool & what run time & % do you normally run them on?

 

[kellyfair]

I wish SWCG manufacturers did a better job of explaining troubleshooting, without immediately resorting to “time to clean cell.” Although that would mean lower sales on replacement… ok, never mind.

I think over the multiple years I owned the Intex set up, I cleaned the cell twice.

 

[Jocko]

Welcome to TFP! When a cell begins to show signs of inconsistant readings, two things come to mind. Either an old/bad cell, or the cell is compromised from poor water chemistry. You seem to be an experienced SWG owner, but we'd like to rule out water chemistry before assuming your fairly new cell is bad. So let's start with some questions for you:

- How you are testing the water? Which test kit?
- Can you post a full set of water test results?
- Have you been finding scale on the cell plates?

Unfortunately in Thailand where I live we do not have any Pool Specialists to take water for full testing and we have a limited avaialbility of test product to purchase, we don't have Amazon etc. So to answer your questions'
Testing the Water - Test Kit (3) - I use a Poolrite test kit from Australia, a digital water tester & test strips.
Full set of results n/a as detailed above. From my own testing; Ph is always on the high side and needs acid to reduce averaging 7.8 Alkalinity 160mg/l. Free Chlorine always low from Day 1 around 0.5 Total Chlorine 1 Hardness not sure maybe 1,000
The water is hard here and with high calcium levels, flakes are eveident on the floor of the pool from the water inlets.
Scale on plates - Yes, the plates are difficult to see so I use an old plastic ruler cut to size to clean between the slats, the sides have more build up than the centre, then rinse out removing some flakes. Unfortunately due to the poor design of the Hayward cells, (a white casing instead of transparent and a curve which prevents you from accessing one of the 3 sections, to fully clean you have no choice than to use a mild acid rinse 4:1 When the cell is inserted active frothing takes place for maybe 3 to 5 minutes, even though I am cleaning them roughly every 7-10 days this happens every time.

Hope this helps answer your questions, look forward to hearing from you again.

 

[Jocko]

Cleaning the cells with acid reduces their life as it removes the coating that helps produce the chlorine. It is likely yours may be depleted at this point due to the frequent cleaning.
It is recommended to keep your csi neutral to slightly negative to prevent the need to clean them with acid at all.

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.

www.google.com

Their rated life span is around 8k hours @100% output.
How large is your pool & what run time & % do you normally run them on?

Please see previous post, the design of the Aquarite does not allow you to access all areas of the plates so with the problem I have, there is no choice than to use acid. As also mentioned calcium flakes are visible on the floor of the pool between vacuuming sessions. I will check out your point about 'CSI' thanks.
Re your questions pool size is 19m x 9m capacity is 300,000 litres, (80,000 US gallons). I have 2 Hayward Pumps, run time is 2 x 4 hours each Oct-April, 2 x 5 hours each May-Sep (the hottest months). Currently running on 70%, have tried on 100% but salt readings fall quicker the higher % setting, so at 100% they will fall from 3,200 to 2,700 in 7 days max. At 70% 10 days max.
Hope this helps. Look forward to hearing from you again.

 

[Mdragger88]

Csi takes into account many variables not just calcium hardness so you will need to try to adjust your other parameters. Use
PoolMath to calculate csi & adjust the different parameters to see their effect on csi.

Calcium Hardness - Further Reading

www.troublefreepool.com

You also may consider adding borates after doing what you can to reduce ch & csi

Borates - Why and How

Borates - Why and How Why Adding borates can improve your experience with your pool, but is completely optional. If you do plan to use borates, wait until everything else is settled down before adding borates, especially TA and PH. The only situations where we specifically recommend using...

www.troublefreepool.com

You have a very large pool - it is recommended to have a cell rated for at least 2x’s your pool’s volume so you don’t need to run it as much and the cells won’t burn through their 8-10k hr lifespan as quickly.
Not sure what is available to you but 60k rated cells would serve you a little better provided you can get the scaling in check. Pentair & circupool make these.
Pentair also makes a commercial set up for multiple cells

SWG Multiple Cells - Further Reading

www.troublefreepool.com