Water changes is the best brand to use. If you don't want to do that, I have always liked the Seachem brand. I have found all of their products to be very stable, low precip., and good at maintaining levels for certain periods of time. I try not to dose that often though. I do about 40-50% water changes once a week.
PS: I couldn't really comment on any other brands because I have never used them. Years and years ago someone recommended Seachem and I have used that brand ever since.
Are you feeding a lot?
You can check out Seachem Reef Advantage Calcium. That is the brand that I have used for a LONGGGGGGGGGGGGGGGGGGGGGGGGGGGGG time, LOL. Works extremely well in all of my tanks and tide pool systems.
Calcium isn't necessarily something that you replace with water changes, you do water changes to remove harmful waste buildup as well as replenish trace elements that are used up in the water column.
Tropic Marin "reef pro" I think it is has a lot of calcium in it. If you truely want to add calcium to your tank, research how to dose with "Kalkwasser." It's nothing more then calcium hydroxide. Follow the directions carefully and drip the solution into the tank over the course of the day.
Originally Posted by jman72 http:///forum/post/2594954
I'm not adding only calcium. I'm also adding iodine and a compound that contains soome other trace elements.
What is your current Iodine level?
Make sure you test what you dose and only dose elements that you test.
Alkalinity is consumed far faster than calcium so make sure you test your alkalinity.