ro or ro/di

[fishface]

ok, i just looked aquasafe up on ebay.ca and there's a few of them, aqua home, aqua aquarium, aqua maximus and aqua safe. some have tanks, some not, some look like you can buy right away, others you have to bid. PITA or what?

so what's the diff? also, can someone tell me do i need ro/di or is ro good enough?

thanks