I've posted pretty much this same question here
, but thought it'd be worth posting a separate thread.
I'm going to attempt converting my Evolve 8 into a mud tank, but I'm torn between going the MTS route versus a straight up "dump in some dirt, cap it & go" method. I'm wondering if I can use rinsed Miracle-Gro combined with a bit of clay as my bottom layer, with 1mm clear Silica as a cap? (Planning to use a steep front-to-back grade with the bottom layer used only in the rear half of the tank - it will most likely be ~1-2inches of soil layer with ~1inch Silica layer in the rear section)
All my research indicates this is a viable idea, but I'm wondering if I can use clay found in a local lake? My family has a camp on Lake Spofford in NH, and ever since I was a kid I've been digging up big globs of clay from the lake bed. The stuff is greenish, very dense with very fine granules, and seems to be quite uniform in composition.
My worries include potential hitchhikers - critters & bacteria especially. Is this a legitimate fear or am I overthinking?
My other main concern is that I don't know what the chemical composition of the clay is and as far as I'm concerned it's a total crap-shoot as to whether it'll provide any benefit to the tank. Does anyone have any experience using "wild clay"?
EDIT: Third concern is that it's very silty, and when dried becomes powdery - might this just gunk up my tank?