What is on that top rock on the left pile? Just to the left of the outlet..

ok. just don't get gobies :wink:

they are a bunch of zoo's that came with the rock.

Thats a nice bonus..

the rock is a couple of years old, it starteed out as quite a small patch, and has grown nicely

I have yet to get something that interesting on my live rock. Though yesterday I found out I had a feather duster on one.. So that is a cool find.

Most gobies would be fine, imo, just not an engineer goby. Man, those guys are on a mission to dig under EVERYTHING :eek: When we had an E Gobie, we place large pieces of rock on the bare bottom, added the sandbed, then placed the rest of the rock on the half-buried rock. E gobie had lots of places to tunnel and the rock structure was sound.

Currently have a spotted gobie of some kind in our 42 where rock has been placed on the sandbed. It had burrowed under one particular rock with no ill effects to the entire rock structure.

If you find your getting to much direct flow from the single return, you could always split the return with a "T" fitting or better yet, add a SQWD wavemaker to your return line-then you will have two lines for flow. One of which you could blast at the rockwork and the second into the the open H2O space :mrgreen:
cheers, Rich