OK. I just had to run some calculations.

1. Adjust your pH down to 6.8. See http://pool9.net/muriatic/

2. Use borax to bring it back up to 7.0 http://pool9.net/borax/ Start with 1/2 box doses.

3. Do NOT use baking soda ('Alkalinity Increaser', sodium hydrogen carbonate, "Balance Pak 100") or washing soda ('PH Up', sodium carbonate, "Balance Pak 200").

4. Continue to aerate your pool.


Once your carbonate alkalinity = 60 ppm, you should be able to soften submerged scale if you keep the pH around 7.0 - 7.2.

With respect to your heater corroding, pH values and salt levels are the 2 factors to watch. If your pH is 7.0 or above, it's fine. Do you have a salt system?

With respect to your heater scaling . . . it's almost certainly already happening. Lowering the pH and carbonate alkalinity will help soften and strip the scale.