This is my first post and its something that has been bothering me for the past year. I have a 18k gallon salt water in ground pool. the old pool was regular gunite and had been painted by previous owner. I've been getting these white nodules around the pool where the tile meets the pebble. 3 months ago i did a partial drain and using a 50/50 mix of muratic acid and water dissolved/scrubbed the away. looked great but now they are coming back. i think it may be calcium being pulled out of gunite there at the border? Should this border be sealed? pool looks great and this is the only area where these nodules appear. there is NO scaling anywhere in the pool or the salt cell (hayward 40K)
Any help would be great.
hardness 300 or so, depends on who you ask
I use 8oz of metal out every month, seems to help but not enough