Eight months ago I set up my very first blackwater aquarium for my half moon Betta, and in this update I’m going through what’s genuinely been great, what’s been not so good, and what I’d change if I started again. I cover how the tank has matured over time—tannin levels, water conditions, and the overall stability you can get when you let it behave like its own little ecosystem. I also talk about fish behaviour, because my Betta is absolutely more “Betta” in here: more foraging, more hunting, and just generally interacting with the leaf litter in a way I never saw in a standard planted setup. I also show you my maintenance routine: how I prep botanicals (yes, I boil them), why that mulm layer is actually important, and why I still remove some of it to avoid the substrate going anaerobic. Then we get into the big reality check—filtration takes a battering in blackwater. I give an 8-month update on the Oase EcoFlow internal filter, including how grubby the media and impeller get and why that matters for flow and upkeep. Finally, I break down the key trade-offs: plants don’t really thrive in this kind of low nutrient/low light environment, cycling can be trickier at lower pH, and fish choice is massive if you actually want to see your livestock. If you’re thinking about starting a blackwater Betta tank, this is the stuff I’d want you to know before you dive in.