Hi CD;

Sorry about the question about clarity -- didn't mean to ask that. Just when someone tells us the water is balanced, without numbers, we've learned it usually isn't.

OK, you've got some hard fill water. If those numbers are correct (remember, I don't trust the Rainbow kit -- it may be OK, but I don't know) AND if the AquaRite is working properly, you shouldn't be picking up scale. Let's do this:

1. Chlorinate manually for now. An easy way to do it is with undiluted dichlor
==> Sams Club "PoolBrand" 24lb box of dichlor shock - EXCELLENT price, if available. Otherwise
==> Kem-Tek Dichlor 22 lbs @ Amazon
(Almost all other locally available brands are diluted or mixed with goo.)

2. Raise your CYA to the recommended 80 ppm (if you use dichlor, you'll do both)

3. Clean your SWCG cell, per Hayward's AquaRite manual, pgs 8 & 9 (page order screwed up!):
Servicing and Cleaning the Aqua Rite cell
Turn off power to the Aqua Rite before removing the electrolytic cell. Once removed, look inside the cell and inspect for scale formation (light colored crusty or flaky deposits) on the plates and for any debris which has passed through the filter and caught on the plates. If no deposits are visible, reinstall. If deposits are seen, use a high pressure garden hose and try to flush the scale off. If this is not successful, use a plastic or wood
tool (do not use metal as this will scratch the coating off the plates) and scrape deposits off of plates. Note that a buildup on the cell indicates that there is an unusually high calcium level in the pool (old pool water is usually the cause). If this is not corrected,
you may to have to periodically clean the cell. The simplest way to avoid this is to bring the pool chemistry to the recommended levels as specified.

Mild Acid Washing: Use only in severe cases where flushing and scraping will not remove the majority of deposits. To acid wash, turn off power to Aqua Rite. Remove cell from piping. In a clean plastic container, mix a 4:1 solution of water to muriatic acid (one gallon of water to one quart of muriatic acid). ALWAYS ADD ACID TO WATER - NEVER ADD WATER TO ACID. Be sure to wear rubber gloves and appropriate eye protection. The level of the solution in the container should just reach the top of the cell so that the wire harness compartment is NOT submerged. It may be helpful to coil the wiring before immersing the cell. The cell should soak for a few minutes and then rinse with a high pressure garden hose. If any deposits are still visible, repeat soaking and
rinsing. Replace cell and inspect again periodically.
4. Lower your alkalinity to 60 - 80 ppm (fine for vinyl pool): Lowering your Alkalinity Step by Step

5. Once your CYA> 75 ppm, your pool is algae free, and your TA < 80 ppm, turn your SWCG back on.

6. Re-inspect after a week, for scale. If there's no scale, simply continue, and maintain these conditions. Shock with bleach, when you need chlorine but no CYA; shock with dichlor, when your CYA is drifting down.

7. Maintain pH with muriatic acid (lowers) and 20 Mule Team Borax (raises). Do NOT use baking soda or washing soda (pH UP)

If this fails, we'll have to get fancy. But if this works, it's cheap and stable, and won't create other issues to watch out for.