cut cardboard to the size of cave you want.
arch and brace it,then tape it to a big piece of cardboard.
start using silicone between each rock.
work your way up side by side.
silicone everywhere a rock touches a rock for strength.
let dry and remove cardboard.
i used large river rock because thats whats in my tank.
next one i will use gravel and do it the same way.
i will post finished,in tank, pics when its dry.
i might trim some silicone off when its dry.
arch and brace it,then tape it to a big piece of cardboard.
start using silicone between each rock.
work your way up side by side.
silicone everywhere a rock touches a rock for strength.
let dry and remove cardboard.
i used large river rock because thats whats in my tank.
next one i will use gravel and do it the same way.
i will post finished,in tank, pics when its dry.
i might trim some silicone off when its dry.