I just made 3 small "plates" of it. It is still curing, so I don't really have alot of feedback to provide. All I used was cement and crushed oyster shells...no real exact ratio, but probably close to 2:5 (cement to shells). Water runs straight through it

It feels light and "airy" (is that really a word?)
This week I will put the MMLR plates into my toilet tanks to finish the kuring process (different from "curing"...not a typo). I shoul dhave it kured in 2 to 3 weeks in the toilet


...then it will spend a few days in some plain water to test if it is now tank ready.
If anyone will be interested in the results, please PM me or bump this message again in a months time. I hope to have my results then.