The ideal salt level is between 2500-3000 ppm (parts per million) for this model - the optimal level is 3000ppm. For a round pool with your dimensions of 15 feet across and 48" deep, with the water at 80% capacity (it's not filled to the top right?) = 3736 gallons. So the amount of salt you need to add initially to get to 3000ppm is 95 lbs of salt. When low salt is detected (Code 91) you are supposed to add 20 lbs of salt (what the manual says). Here is a link to the manual that I found : (see page 133) https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiQxM-mmNHNAhVH52MKHRkCDe4QFggjMAE&url=http%3A%2F%2Fslink.intexdevelopment.com%2Fproifv%2Fproifv_dl_loadblob%3FEMTKEY%3D15617&usg=AFQjCNEp2w45MYXqkkb9Edb-Qi5XJ6-03A&sig2=vgHWvP
Answers & Comments
The ideal salt level is between 2500-3000 ppm (parts per million) for this model - the optimal level is 3000ppm.
For a round pool with your dimensions of 15 feet across and 48" deep, with the water at 80% capacity (it's not filled to the top right?) = 3736 gallons. So the amount of salt you need to add initially to get to 3000ppm is 95 lbs of salt.
When low salt is detected (Code 91) you are supposed to add 20 lbs of salt (what the manual says).
Here is a link to the manual that I found : (see page 133)
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiQxM-mmNHNAhVH52MKHRkCDe4QFggjMAE&url=http%3A%2F%2Fslink.intexdevelopment.com%2Fproifv%2Fproifv_dl_loadblob%3FEMTKEY%3D15617&usg=AFQjCNEp2w45MYXqkkb9Edb-Qi5XJ6-03A&sig2=vgHWvP