I'm attempting to create a salt marsh in a 190 gallon tank. The salt marsh I'm modeling is one that could be found on the coastal barrier islands of Georgia or slightly further south, with bank vegetation dominated by Spartina spp., Salicornia spp., and Batis spp.. Animals consist of mud fiddlers, mud crabs, ribbed mussels, periwinkle snails, killifish and various and sundry polychaetes and non-flying hexapoda. All animals are species that normally are found together, predator-prey relationships between mud crabs and the fiddlers and predation on the periwinkle snails are somewhat in equilibrium (watching populations to see if one is getting dominated, so far so good).
The substrate used is largely the natural mud substrate found in the salt marshes. Very fine clay particles suspend themselves in the water column and this makes water quality maintenance difficult. What I've resorted to is a secondary tank that operates something like a sump, with a phased system that does not operate continuously. Basically the sump pumps water into it (resulting in a low tide in the marsh tank), and then lets the water settle for about 2 hours so the fine particles come out. Then it begins to cycle water through a system with physical filters and biological filters. After a few more hours the water is cycled back into the marsh tank. Tidal cycles are replicated against tide tables for southern Georgia. The biological filter consists primarily of various macro algae and live sand, but even with the settling time, the fine clay particles sometimes get in and wreak havoc on this portion of the filtration.
Any ideas on how to solve the fine clay problem? It seems like I have to replace the biological filtration portion every month due to clay sedimentation, and if I try to physically filter it, the filters get clogged extremely quickly.
P.S.- First time poster, aquarium novice
edit: missed the '1' on the tank gallon size