Rib cage in construction process:
After a frustrating afternoon with the hydrolic cement I switched plans and used black UV resistant pond foam to hold it all together. (that and about 50 zip-ties) I have been researching rock walls and pvc structures over on RC for the last few months and am confidant that the foam is good to go in the tank.
I will coat the foam in epoxy resign and stick argonite to it. The consensous on RC is the the black pond foam doesn't need to be epoxied but I am going to do it anyway to be safe and make it sticky to be able to completely hide the foam with aragonite.