Sorry to barge in uninvited but I came upon this thread while searching for some info to give a friend.
I just want to make sure there is no confusion as to what's going on with your ca and alk numbers and I apologize if I'm re-stating something thats been covered here or otherwise obvious.
A better term for a calcium reactor is "calcium carbonate/carbon dioxide reactors" as it uses carbon dioxide to release calcium
and alkalinity in a balanced ratio. This means that for every 20ppm calcium increase your get from your calcium reactor you will see about a 1mEq/L (2.8 dKH) increase in alkalinity.
When you see your alk go up by .3 your Ca would only increase by bout 6.6ppm which might be beyond the resolution, or error, of our hobbiest test kits.
If you want to go from 375 to 420ppm Ca with a Ca reactor you would also expect a 2.25mEq/L raise in Alk.
I believe this is why its recommended to get your levels to where you want them,
or at least balanced, then use the reactor to maintain them.
This info was taken from
this article.
Btw, love the 65g setup! I'm running a 65 and it looks no where near that nice under the tank. You fit everything in there very well!
