I believe the need for brackish water has something to do with molting properly. How long have you been able to keep them in a freshwater setup?
There are a number of brackish algae eaters that could go in a tank that size. MTS and amano shrimp come to mind. One of best algae eaters in the hobby - the florida flagfish - can also be kept in brackish.
There are a number of brackish algae eaters that could go in a tank that size. MTS and amano shrimp come to mind. One of best algae eaters in the hobby - the florida flagfish - can also be kept in brackish.