As a place for phos-ban and or fuge? I did this on my 29G with good success years ago for carbon. Is this an OK place to put phosban and/or make a mini-fuge as well? I basically chunk everything except the pump and casing for the filter media, replace the media with some mesh to help contain things inside. I don't run a sump, but wanted to try out phosban on this tank instead of the carbon I used last time. Would that be more beneficial than a roughly 1 Gallon refugium? I also did that on my 55G to so-so success. It seemed the macro algae would find a way to slip back into the tank and grow faster there than in the hob filter, lol.
Upsides/downsides, or does this really require a media reactor?
Upsides/downsides, or does this really require a media reactor?

