charlie sells ceramic in bulk. are you using canister filters or a sump? i have 2 fluval 405 loaded with pure ceramics on my 150 for bio as well as 2 double sponge ac110s. just an example.
One or two can work depending on what's in the tank. The more rock, driftwood, substrate, and other various hard surfaces in the tank the more bb in the tank and the smaller the demand for bio media in your filter. The sponges in your canister will also have bb.