250l reef with canister filter only... A bad idea?

Hi all

I have a quick question. How feasible would a 250l setup be with only a
Fluval 404, a couple of small powerheads and lots of live rock? Is all the
other paraphernalia such as skimmers absolutely necessary? Essentially all
I want is a couple of small fish, and some of the easier to keep inverts. I
have seen a couple of nice setups like this. If it's a bad idea I'd rather
not and stick to my malawis....

Thanks
Simon