I plan on making it all petricola

They will be purchased as babies.
I think perhaps the poster above was thinking about young fish without regard to adult size. I'd say 20 10cm adult in a 90cm tank is not a good idea. So, six max in a 30" tank. Less if you take into account that to get the most out of these fish they like dithers.feesh wrote:How many adults comfortably will fit?