Are there alternatives to a refugium?
This depends on what function you are looking to get out of your refugium. If you are simply looking for a refuge for copepods, amphipods and other such organisms to help feed your main tank, unfortunately there really isn’t with the exception of purchasing the packaged bottle or bag of copepods some places offer. But that can get fairly expensive to keep adding bottles of them to your tank a few times per month (or more). If you are looking for a natural way to help reduce nitrates and phosphates, you could try using something called an Algae Turf Scrubber (ATS). Basically an ATS uses a medium to grow algae on while water is sprayed, dumped or trickled over it above the water surface. The algae growing on the medium is then harvested a few times a month (or as often as necessary) to help with nutrient export, similar to the way you will need to harvest the algae out of the refugium to allow room for the algae to keep growing.
