I am planning to do a 3d background for a 125 gallon tank. Can I use the foam and cut out my rocks then paint it with krylon and then use some type of clear coat or glaze with sand on top to give it texture? And if so what would you suggest for the coating? Thanks
I found that the best way (to me) is to use styrofoam cut out the way you want. I use Latex Drylok and color it with quikcrete cement color. Heat the styrofoam with a heat gun or blow dryer which will give it a more solid texture. I engrave my rock with a grill lighter to give it character. Use GE silicone #1 to stick it to the glass. Use plenty of it to prevent boyuancy but try to keep it from coming out the edges because your Drylok wont quite stick to the silicone real well. If you have gaps between the rocks, use Great Stuff foam to fill them in. Mix your drylok and paint it up. About three coats. NO ISSUES WITH pH, curing, etc. Holds up really well. Done about 5 tanks this waywith no issues.