Hey Giancarlo I am in the same boat, i used to use RSCP but recently ran out and didn't want to continue to use due to the higher Alk that it was mixing at (mine was mixing at >10dkh at 1.026 spg) although i do like the salt a lot and used it for several years.
I tried going back to IO reef crystals but decided to not use anymore because of difficulty in mixing completely and some residue left over in the bucket (of which i got none with RSCP).
After seeing the Aquacraft thread on marine salt testing and taking a look at their params (1.026 / 77F: Ca 445 ppm, KH 9.25-9.50, Mg 1340 ppm) I've decided to give their salt a try, I think they are worth looking into.
I was also looking at Aquavitro which i have heard works well from some buddies. Here are their params according to website:
Calcium: target 422 mg/L, range 400 to 443 mg/L
Magnesium: target 1336 mg/L, range 1269 to 1403 mg/L
Strontium: target 8.4 mg/L, range 8.0 to 8.8 mg/L
Alkalinity and pH values vary widely over the Earth's oceans. salinityâ„¢ will be within the following ranges:
pH: 8.4 to 8.6
Alkalinity: 3.2 to 3.8 meq/L
Wondering what other issues you had with RSCP?