Beginner Freshwater Aquarium
I have a newly set up 35-litre tank measuring 44cmLx42cmHx27cmW (roughly 9 US gallons, I think - 17.3"x16.5x10.62 inches). The filter has "bio-balls", then a bag of carbon wrapped in filter material, then "bio-rings". I have a 50W heater and a small airstone in there as well.
I have been...