You don't need it if all four sides of the tank making contact with the plywood. You will need it if only the bottom piece of the tank is making contact. I don't use one on my big cube b/c all 4 sides are making contact to the plywood.
You don't need it if all four sides of the tank making contact with the plywood. You will need it if only the bottom piece of the tank is making contact. I don't use one on my big cube b/c all 4 sides are making contact to the plywood.
Reefing is just like cooking, all the ingredients have to be just right , except you don't have to bring the water to a BOIL...