CUC size determined by what?

[PSU21Reef]

I currently have a 54 gallon corner with a small CUC. I am downgrading to a 28 gallon LED. I'm going to have it pretty full with live rock and wanted to know if the size of my CUC should be determined by the tank size, amount of livestock, or by the amount of live rock in the tank? Thanks.

[Octoshark]

As far as algae growth and buying herbivore CUC's you would want to look at surface area as more surface area means more area for algae to cover. If you have a lot of livestock and feeding tends to be messy, then you may want to take that into consideration when determining your carnivore/omnivore CUC size.