Morning, Just about to put an order in at aquaessentials and under there co2 section i noticed they have disposable Co2 options: The Tetra Optimat and the TMC Aquagrow Co2 Kits. Both relatively cheap. Did a quick google search and on Oliver Knotts website he seems so use the Tetra Optimat on his nano set up and it looks really good. Did a quick post search on here and the main thought on these are they suck? Do they? My Set up: 16ltr glass fishtank, 11w light, Colombo flora base subsrate and use TPN+ as my fert. I am planting some crypts, pogostemon helferi and maybe some marsilea. So fairly low tech. Is Co2 essential in this set up or can i save some money and avoid it?