The Tunze was a good choice. I actually bought the CPR SR3 for my BC29 and returned it after three weeks. Perhaps it was something I was doing wrong- I won't deny that, even though I did speak with CPR's tech support person several times. It always seemed difficult to dial-in the flow of bubbles accurately, and the skimmate was always pale and watery even just before water changes. It was a bit noisy. I think the thing that bothered me most was I could look at this skimmer sideways, and my tank would FILL with microbubbles. It happened when I'd top the tank off, empty the cup, etc etc. The bubbles would subside for a while, and then return. The SR3 fit well with no mods and took up most of the middle chamber. I did give it three weeks and was never that happy with it.
I bought a Tunze after that, and there was a huge difference. It installs with some really powerful magnets- watch your fingers. There were never any microbubbles in the tank. Ever. It was so quiet I had to check to see if it was really running. Dialing it in is very sensitive, but once you hit the right point, it is consistent. The skimmate has become tea-colored and thicker. It's considerably smaller than the SR3, and I have about a 4X4" section left in the middle chamber now. In order to get the cup in and out, you do have to make a very small mod to the tank with a dremmel or something. It is minimal but well worth it- you'll see what I mean. Good luck!
