High CYA and high salt ppm

[reggiehammond]

Thanks! (and hello from Hillsborough, neighbor!) We just finished exchanging 6000 gallons, and now CYA is measuring around 90. The SWG is reporting around 3000ppm instant salt and 4000 ppm average salt. I'll need to read the manual to figure out what that means. One thing I'm curious about is that sometimes it says the current is 0.0A, and sometimes it's non-zero. We measured alkalinity, calcium, and ph within expected ranges after the exchange. Hoping we're on a road to recovery and will have this balanced out fairly soon.

SWCG runs opposite polarity to fight potential for scale - that's why you see positive and negative numbers. It also does not run continuously, which is why it can read as basically off, voltage-wise.

I wish I had gotten to your thread sooner - your CYA is too high for how long you had low FC. You likely need to SLAM, but that's borderline impossible at 90 CYA.

An Overnight Chlorine Loss Test with SWCG off would be a good next move.

 

[JonasBailer]

So we replaced about 6000 gal. of the 17k pool and CYA is now measuring around 60. Our combined and free chlorine are still very low - about .6ppm each. Everything else seems to be in normal range though (pH, alk, hardness). I have the SWG running at 75% to see if that helps.

 

[PoolStored]

So we replaced about 6000 gal. of the 17k pool and CYA is now measuring around 60. Our combined and free chlorine are still very low - about .6ppm each. Everything else seems to be in normal range though (pH, alk, hardness). I have the SWG running at 75% to see if that helps.

Awesome!

You should use liquid chlorine to raise FC and SWCG to maintain it. SWCG not really good at raising.

Remember to follow these recommendations! Link-->FC/CYA Levels

I would also suggest that you perform an Overnight Chlorine Loss Test. Will tell you if you have algae brewing. Better to catch it sooner! Link-->Overnight Chlorine Loss Test

 

[reggiehammond]

So we replaced about 6000 gal. of the 17k pool and CYA is now measuring around 60. Our combined and free chlorine are still very low - about .6ppm each. Everything else seems to be in normal range though (pH, alk, hardness). I have the SWG running at 75% to see if that helps.

SWCG are useless against algae and they're not good methods of trying to raise chlorine levels from 0. They are fantastic at maintaining, especially with no algae present.

Before you do much more - OCLT and a likely SLAM are in your future. You can't have chlorine that low, for that long, without algae being present. Sorry your pool company got you in this bad spot - but it's ultra common.