If you break the flow up, you can have much more.
If your choosing to just go with a powerhead, get a kind where the flow is broken up more out of the powerhead, like a koralia nano. Powerheads that have a small jet stream style flow, like the rio's, are not as good IME.
Goal is to not have any area the seahorse can't swim through, and not have a current that will blast the seahorse into the rocks. If the current it to strong they will be less active.
JME
