Fish only tank.... Need rock?

[paddyob]

Originally Posted by sphelps

Nope not needed. Lots of commercial fish only displays use ornaments and zero actual rock. You'll just need some sort of bio-filter.

Many use a sump system and all the rock is hidden.

[sphelps]

Originally Posted by paddyob

Many use a sump system and all the rock is hidden.

Perhaps but that would be unusual, typically the sump would house a bio media like ceramic or plastic bio-balls since it's more effective and takes up less space.