Yes...we did have scaling in the spa previously, which was a PAIN. I'm glad to hear that a negative CSI will work.
You bring up a good point. I'm guessing the spa probably isn't vinyl. Our pool is vinyl but the spa is probably fiberglass or something of a hard shell similar to what boats are made out of. I have no idea about gel coat. I inherited the pool and spa when I got married. My husband was a bachelor living here for 10+ yrs before I met him and he bought the house for the pool and then purchased a spa to complete the "bachelor pad."
I will keep the CSI number for pools in the back of my head; especially since our native water seems to have both high TA and high CH. Speaking of which - I am currently aerating the pool in an attempt to avoid scaling. I found our TA had drifted upwards recently and the Calculator indicated we were at risk of scaling (I don't recall what our number was, exactly. I have NO desire to scrape scale from pool walls, so we are at the tail end of an acid/aeration cycle.
I ran the numbers to see about adding 50ppm of borates to the pool to help with all this. Calculator told me I needed something like 76 boxes of Borax! What?! That's crazy volume.
Anyway - thank you so much for all the help these last few days.
Molly
You bring up a good point. I'm guessing the spa probably isn't vinyl. Our pool is vinyl but the spa is probably fiberglass or something of a hard shell similar to what boats are made out of. I have no idea about gel coat. I inherited the pool and spa when I got married. My husband was a bachelor living here for 10+ yrs before I met him and he bought the house for the pool and then purchased a spa to complete the "bachelor pad."
I will keep the CSI number for pools in the back of my head; especially since our native water seems to have both high TA and high CH. Speaking of which - I am currently aerating the pool in an attempt to avoid scaling. I found our TA had drifted upwards recently and the Calculator indicated we were at risk of scaling (I don't recall what our number was, exactly. I have NO desire to scrape scale from pool walls, so we are at the tail end of an acid/aeration cycle.
I ran the numbers to see about adding 50ppm of borates to the pool to help with all this. Calculator told me I needed something like 76 boxes of Borax! What?! That's crazy volume.
Anyway - thank you so much for all the help these last few days.
Molly