Calcium Hardness

[ndillon2]

I tested with a drop kit and strips
FC is currently zero as the SWG has been clogged, not producing. I bypassed it yesterday and supplemented with bleach. I will continue until the cell is replaced
PH = 7.5 I have been maintaining at that level with approx 1/2 gal acid per day
TA = 80 been fairly steady for last couple of months
cya = 70 (adjusted 3 weeks ago from 40
CH = 1000 (test strip test)
temp = 80-84

I have had this problem for two years, constantly battling the SWG clogging abut every two days. I also have the scale ring around the perimeter on the tile. Assistance appreciated.

[chem geek]

If your Calcium Hardness (CH) were truly only 1000, then with a TA of 80, CYA of 70 and pH of 7.5 (and assuming 3000 ppm salt), your saturation index is only +0.14 which isn't high enough to produce the kind of scaling you are seeing. However, maybe your test strip is not able to measure super-high CH levels. However, you'd probably not see scaling unless your CH was closer to 2000 ppm or more. That would explain your situation.

Do you know the CH level of your fill water? Can you measure that separately and let us know? It would be better if you had a more accurate drop-based test for measuring the CH level especially since it is so high (i.e. a Taylor K-2006 test kit or Leslie's Chlorine FAS-DPD Service Test Kit or for just the CH test, the Taylor K-1770 here where you can use the 10 ml sample so each drop will be 25 ppm). As for what to do, that will depend on your fill water so let's get those results first.

Richard

[ndillon2]

Fill water CH is 200 (test strip)

I tested everything today as follows:
CL = 1
PH = 7.6
CYA = 50 (added stabilizer to bring up to 80)
TA = 80
CH = 1000 (test strip)
CH = 460 (pool store test).

The pool store recommended AllClear Stain and Scale for the hardness
I cleaned the salt cell yesterday and this morning it was fully clogged with scale. Flakes continue to come out of the return lines and congreagte on the step just below the return.

Is it possible that scale has built up on the walls and as it breaks up and is sucked through the filter it then clogs the salt cell?

[waterbear]

There are NO test strips that I know of that measure calcium hardness. They measure TOTAL hardness (magnesium and calcium)!

[ndillon2]

You are correct. My strips test Total HArdness (1000+), while the pool store tested Calcium Hardness (460). Thank you for pointing that out. At least I feel A bit better about the results being so different.