I'm going to hijack this because it is a similar question and I have been reading a lot about carbon dosing. How do you know if you should start implementing in my case probably vinegar. I am still battling with cyano and I know that vodka especially can cause a cyano bloom. The reason I ask is the tank is about 4 months old now and I have been doing the same water change schedule since after the cycle(pretty large water changes) like I said earlier I take everything out of the sump and rinse it out. The rubble gets swished in the water coming out. The rest of the sump gets rinsed with ro waste water and then the inside wiped with towel to get all the slime out. I like my sump clean. For the past 3 1/2 months after a water change nitrates are almost undectable. Yesterday day I changed out 28 or so out of 67 gallons it was split up Tuesday night (siphoned sand bed) and Wednesday morning did the sump. After that tested nitrates and I was at about 5ppm. Before the water change I was up to 10ppm so the water change did drop them by half like it was supposed too. So as the tank matures more do I need to start thinking about carbon dosing. Even though I am still fighting the cyano with the increased flow, lowering phosphates and weekly dosing of microbacter7. I have read about vodka and microbacter7 combo. I know that 5ppm Is still pretty low but say next month before water change I'm at 20 and change less for whatever reason then my baseline nitrates are higher.