Hey all so my ATI sunpower is arriving tomorrow and I want to get over the tank tomorrow or Tuesday. I know when hanging the light you have to know wether there's a joist or drywall. That's the issue, I believe there's no joist over the tank and my home is older so therefore is believe its plaster. I want to mount it from the ceiling not the wall... so what are my options if there's no joist or drywall? Can't mount it?