I finished my first box of the Fritz Rpm a week ago. Really good stuff.
Mixed to:
1.025 sg
Cal = 440
alk = 8.5 dkh
Mag = 1400
Reef loved it.
Lol,
But... Just went back to regular instant ocean and dose up if needed. Just can't beat the price and I really can't tell one salt mix from the others in my reefs health.
The RPM is a great mix if you like those #'s and is crystal clear and ready to go in 20 min. :)
The only complaints that I've seen on the RPM is that if you mix it up and let it stand over night that it clouds up with precipt. but I always left my mixing pumps on overnight for the next days water change. So I can not confirm if it precipts. if you were to store it.
If I see any decline in my reef from going back to IO (Then I'll be using the RPM from now on) but I'd be really surprised if there's any difference.
If you don't want to dose up, then I highly recommend the RPM. :)
Regards, GoVols