I think the Geo reactors are the best and easiest to run. I have a 612 on my 115gal and will be installing (today or tomm) a 618 on my 214gal. Good luck. You are off to a good start.
Premium Aquatics is the only place Geo sells the 612 reactor to, if you have that one. The other sizes are avail at other places. I also use about 10-15% of ZeoMag in the media with 80-85% being another Ca media of your choice.
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