Calcium and Alkalinity
 

Best suppliments for dosing/maintaining calcium, alk, and magnesium levels? Kent tech cb, Brightwell Reef Code A and B, mag suppliments???

All of the commercial two-parts seem fine for calcium and alkalinity, although they might differ in cost. I've used the Kent and ESV magnesium supplements, and they are fine. The SeaChem is mostly magnesium sulfate, so it's not worth getting it, in my opinion. There are DIY recipes that will work, and will save some money, as well.

Personally, I'd stay away from Brightwell, since there seems to be a great deal of high-pressure marketing associated with their products, and at least at one point, it was difficult to get them to publish the ingredients.

A heck of a lot of us simply mix our own from calcium chloride, sodium carbonate/bicarbonate, and magnesium chloride/sulfate. Have you read Randy Holmes Farley's article on DIY two-part dosing? His recipes are pretty much the gold standard of 2-part dosing, and folks like Bulk Reef Supply have made quite a business of supplying the ingredients in convenient packaged proportions.

DIY
http://www.reefkeeping.com/issues/2006-02/rhf/

Although this may seem like an elementary question, do you reefers that supplement also do regular water changes? If so, how often and why?

Something like 10-20% a month should be fine. There are a lot of problems that water changes can prevent:

http://reefkeeping.com/issues/2005-10/rhf/index.php

The DIY 2-part all add NaCl (table salt) over time because the primary ingredients are calcium chloride and sodium bicarbonate. Water changes and dilution are the key to keeping the ionic balance and salinity in the reasonable zone.

I also like the BRS 2 part. It is pretty cost effective and has good instructions and videos to help mix correctly.

Can you explain why table salt is added. I have been using the DIY 2 part for a couple years, but only when needed to supplement the calcium reactor.

How would you know if you needed to add table salt?

What he was saying is the process of dosing adds salt over time. Regular water changes balances that out.

I dose BRS 2 part -- if I lived somewhere that had snow I would buy the dow flake like in Randy's article. Might have to go by home depot next time I am in the mountains =)

Calcium chloride is CaCl₂. Sodium carbonate is Na₂CO₃ The corals consume the calcium and the carbonate, leaving 2 NaCl for each molecule of calcium carbonate created. Those are the two primary ingredients in the DIY, so that effect dominates the ionic shift.