Refugiums are pretty neat. Just another place to grow more plants :spoton: . To me the mud would be annoying to change out. I understand the philosophy to the system. However, I never believed in the whole "I go a month
+ without changing water" . It's against my religion! I do grow plants in my sump "Refugium". There is a crypt, Anubias and some mosses growing under an LED.
My Refugium is the fish tank itself. Half the sump is for removing gunk. The other half supports biological filtration. About every 3-5 months I rinse
1 filter in my sump, rotating between 2 different sponges (that's this guys equivalent to reaching in his sump, pulling his plants, and scooping out a bunch of organic mud. Wonder how much that stuff cost - :scratch
. My prefilter (to his "sock" ) I rinse about once every 2 weeks....maybe....
The best modification I've made to my 30 gallon sump is the hook up of a water changing system. You may want to consider this with a large tank build. It's hooked directly to my water system with a drain that leads outside. I flip it on for about 2 hours every week changing out about 15-20% water every week.
I hardly get any algae's in my 140. Nitrates are at 0.