surface area for growing adequate bacterial culture to handle the waste products of your fishes. you could get less depending on how pourous the rock is.
The more you have the better natural filtration your tank will have, if you have a good Protein Skimmer you could go with less or some other means of filtration, do you have a deep sand bed for biological filtration?
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
