To link, or not to link....

[Pisces]

I'm thinking about setting up a 25-30gal tank as a coral tank. I have a 130gal fish only with lots of live rock.....but I have some fish (and starfish) that are not reef safe.

I was wondering if it would be best to keep the tanks completely separate.....or have them run off the same sump?

I probably won't do this right away because I need lights first....but I wanted to get my plan started early.

TIA!