I agree. That's why I would suggest a two part. I dose my tank daily in the am, now my tank is sps and clams only so I have a higher demand. And if your balances are in check, dosing equal parts on a daily basis will help you stay off the rollercoaster. In his case he may only need dose 10-15ml a day. That would something he would have to determine for himself.
With a softie tank he may not to dose at all if he dose weekly water changes with a good quality reef salt. If he uses IO then he may have to dose. I agree he doesn't need a high ca and his alk levels need to stay up. But if he can maintain NSW levels he shouldn't have any problems.

sorry I have to talk in lamens terms, Don't speak in scientific lingo to well.
Sticking to basics and good tank maintance will keep you out of trouble every time. Well 99% of the time