calcium reactor
 

what's the best media to put in a calcium reactor?

The ARM coarse media was recommended to me.

There doesnt seem to be many options for media choice. All of the retailers in Canada tend to sell ARM and ARM only. So there is course and fine. If you have a downflow style you might want to use course as fine tends to compact and restrict flow more as it dissolves. If you have an upflow style you can use either.

This is also an economical choice over fine ARM media and only costs about half as much:

Caribsea Florida Crushed Coral Substrate - 15 lbs
http://www.jlaquatics.com/product/cs...-+15+lbs..html

Edit: Not meaning to hijack but I'd love to hear about some other options.

what about dolomite? anyone use that?

I'm using ARM Fine on a upflow with no problems.

Not using dolomite as my Mg is fairly steady but read mix 1:10 with the Ca media.

ZeoMag / dolomite threads

I used to use the ARM fine and it worked like a charm. Only took a pH of about 7.4 to melt it. Then I switched to a Schuran reactor and had to use the coarser media, actually it was Schuran korallenbitz or something like that, anyways, it needed a really low pH of about 6.5 to melt it. I found it really difficult to keep the tank pH steady and went through CO2 like crazy. Not sure what the coarser ARM stuff requires to melt it though.