I am prepared to buy a RO/DI but know nothing about them so am going to have to start doing some research. It seems like a much safer idea.
here is a comparison of synthetic salt make ups: http://reefcentral.com/forums/showthread.php?t=1714505
if you have a lot of corraline algae and keep sps, alkalinity levels can easily drop 1 or more points per day. In addition to your water change schedule you will also need to dose sodium bicarbonate additions daily to offset your tanks usage and slowly raise levels up to recommended levels. The less fluctuation of all your water parameters the more success you will have with sps.
I just bought some RC for the first time, but no way do I want my Alk at 13 going in. Can anyone confirm this number for me. I currently have been using Coralife and have been happy with it.
To the OP: Check your mag levels, you will have a hard time keeping Cal and Alk stable unless your mag is where it should be. I agree with what was said above. Make your own water and mix your own salt. Over time it will pay for itself and avoid the hassle/need to go to a LFS.
Hey guys.. not to side track, but back to RC and alk for a second. I have tested RC salt at 14-16dhk. I mentioned this a while back in a thread, but it seems to work out. I've never tried anything besides RC. I dont supplement either. If I feed and neglect my biweekly water change my tanks not nearly as happy. I do actively tumble my 50gallonbags every once in a while. I also like to keep it dry. This can change results. Good buy on the rodi! Its quite easy to setup and maintain. I would never sell it.
I can give you 10 gal of reef water if you want to take the drive to Northbrook. I can also lend you some alk liquid if you need it.