Cleaning Cell Every Few Weeks

[ssmith579]

I have a Pentair SWG and it works great except I have to clean the calcium off it every two to three weeks. I can tell because the pressure in my filter goes up over 20 because the cell is so clogged. The hardness in the pool is off the scale, stopped adding drops around 700. Anyone else have this issue or know how to keep it from building up so fast?

Thanks,
Steve

 

[Christian]

It sounds to me like you need to lower the CH which can only be done with water replacement or reverse osmosis treatment. What is the CH of your fill water?

 

[bobodaclown]

If you use the pool calculator you can check your CSI. You want to run it in a negative number to avoid scaling. The link is http://www.poolcalculator.com/

You may have to run you PH around 7.3 or so to get a negative CSI. It will really depend on your test numbers.
You'll need the following to calculate Calcite Saturation Index - requires pH, TA, CH, CYA, Temp, uses Borate, Salt

 

[y_not]

bobodaclown has you covered!!

The only thing I would add, is to take a look at the SWG recommendations in pool school.
Very high CYA, in relation to our bleach chlorinated pools is recommended for SWG chlorinated pools. Helps the cell to not have to work so hard, as well as the pure hypochlorous acid that it produces has more effective killing power than other forms of stabilized or liquid chlorine. SO you can maintain a much lower FC level.

pool-school/water_balance_saltwater_generator

Also see the 2nd chart here, for SWGs.
pool-school/chlorine_cya_chart_shock

 

[ssmith579]

Thanks all. I'm renting the house so not about to change out 65% of the water. The CYA in the pool is around 150 and CH is around 750. We have very hard water around here and the owners of the house didn't know how to take care of the pool. They just threw in bunches of chlorine tabs and didn't even use the SWG. I do need to bring the Ph down and hopefully that will help.

 

[Christian]

Unfortunately if you don't get the chemistry in line you are sitting on a ticking bomb that is going to just be a mess. With a CYA of 150 it's only a matter of time until the pool turns into a swamp.

 

[bobodaclown]

I wouldn't use any stabilized chlorine in your pool any more. It's winter, so your pool is cooling down, that may buy you some time from the algae that may grow. With a CYA over 100 it will cause problems. Over the winter your CYA may come down. What's your water temperature? Also where part of the country are you in? You're in a tough spot. High CH and high CYA the easiest is to replace water, but since it's winter and with cool water your chance to get a algae bloom is less. Maybe in the spring when the water is warming up, recheck they CYA and CH.
Keep some chlorine either liquid or the SWCG but when the water cools your chlorine demand will go down.