SWGs are great for maintaining chlorine, but they do not produce it fast enough to keep up with the chlorine demand a shock process requires. Also since your CYA is very low, most of your chlorine produced is burning off at an accelerated rate.
Chlor-bright is dichlor with CYA added. You can use that for now since your CYA is very low. For pools with SWG 60-70ppm is the recommended CYA level.
As far as draining and refilling your pool goes, unless you plan to have softer water delivered to refill the pool, we need to know how much calcium is in your tap water and how much is in your pool before you drain and refill. If you have not used a lot of calcium hypochlorite (such as power powder plus) which increases the calcium in your pool, draining and filling with tap water may not make a whole lot of difference, and I don't want to see you waste your money and time.
It is possible to manage a pool with higher calcium levels if you are diligent. By lowering your TA to around 70 and your pH to around 7.2 and keeping them there you can keep the calcium in solution so it doesn't deposit scale on your pool surfaces. There is a point where calcium is unmanageable and water replacement is required, but we won't know if that applies to you until we see how high your calcium is.
Should your calcium be at the unmanageable stage, you can see if there is a reverse osmosis service for pools available in your area. They can process your existing water and drop the calcium levels significantly. Otherwise your other choice is to drain and refill. If you choose to do this be sure and test the calcium of the replacement water first unless you have softer water trucked in for your refill.
Your cell is in a micro-environment inside the SWG housing. Since SWGs tend to drive pH up and you already have suspected high calcium levels, the micro-environment inside the SWG is a breeding ground for scale. Lower the pH and the TA and that should help with the scale on your cell.
Please go to the user control panel button underneath the TFP logo and add your pool's information to your signature. We need to know the pool volume in gallons, pool type (in ground, above ground), finish (plaster, or vinyl liner), pump brand and size, filter brand and type. It will help us remember specifics about your pool when we make recommendations.
