I thought you were doing beds.... Two per pot ain't a bad idea in case one clogs but you would need a really good pump to run 9 octas. They need a minimum psi to ensure all ports are delivering the same volume. That pump seems too good to be true, I don't think 42watts is gonna deliver the psi you need. Sure it's 1585 gph but as soon as back pressure is put on it I bet it drops massively. It's like comparing an air pump that pumps up your air mattress with cigarette lighter power to an air compressor. The mattress pump will blow up your floatie faster but couldn't put air into a car tire. Ya dig?