I have a 60cm X 23cm floating shelf with 6 X 4mm x 50mm screws with rawl plugs. The shelf is rated at holding 25kg. I also installed 4 L-shaped brackets underneath, each with 3 X 4mm X 50mm screws and rawl plugs. Each of these brackets are rated at holding 20kg.
The shelf is on a brick wall, with a 20kg fish tank on it now, but I'm thinking of upgrading the fish tank to a tank that would probably be weighing double this. Would this be strong enough or would it be best to strengthen some more?