Questions before I buy a calcium reactor.

[andresont]

This is nice unit ! Reverse flow, Ph probe port, pump included and flow meter! could use for bio-Denitrator too. I like it.
I think this is good for 120 the only thing if you keep a lot of SPS then you will need to fill up media more friquently.
Yes you would need to know you PH for sure, for more issues like hair alge likes lower PH and overall system control.
With Calc reactors you PH tends to be on the lower side so Kalk reactor is a big help also for Phosfates control.
look at www.oceanaquaitcs.com in ladner. they used to sell their own but not as nice as the one on your link.