Just Do It! I've been running my CaRx for a little over 2 months now and I'm loving the stability. I was a little worried about the complexity of setup and tuning but once I set it up and got it running it was pretty easy. Many think a CaRx is only for big tank (as I did) but after running it on my 40b, I find it works just as well on smaller tanks. Just need to turn down the effluent flow and/or keep the ph a little higher. I was dosing for the past year and this is sooooo much better! If you are on the fence about running a CaRx, I say go for it!