drop checker co2 covered with algae in freshwater aquascape, dirty aquarium

co2 drop checker test aquarium tank algae green dirty decoration aqua aquatic environment inside aquascaping equipment glass water aquascape plant bba compsopogon black beard brush audocinella rhodophyta riasa staghorn oedogonium freshwater problem growth natural tropical nature fish boraras brigittae underwater animal floral surface bad design ecosystem infection messy trouble biology covered starting