After a very unsuccessful attempt over a year ago and having more free time on my hands, I find myself fascinated with the vibrant colours and intrigued by the keeping of both coral and marine animals. I’m in the middle of planning (saving for) a mixed reef system. I currently have a 660mm x 510mm x 330mm optiwhite tank housing tropic fish which I’m wanting to convert to marine by drilling the rear and adding a sump. So adding the total water volume together I’ll be looking at around 25/30 gal? (If I’m incorrect please let me down gently) The hope is for a bare bottom tank hosting a pair of designer clowns with a mix of soft and lps coral. Whilst the sump is added for extra water volume and a place to hide ugly equipment I’d ideally like to keep the utility bills as low as possible. Meaning is there a way of running a tank naturally with the help of marine pure blocks chaeto etc things that don’t need to be replenished monthly? All help will be greatly appreciated along with suggestions on equipment and stocking. I currently have 2 heaters and a radion xr30 gen 3 pro which has been overkill for the tropical tank.