Sponge filters are relatively easy to maintain. The key is simply to remember to perform the maintenance regularly. The best way to clean a sponge is to perform a water change and save some of the water that was just removed. Submerge the sponge in the used aquarium water, then gently squeeze and release the sponge several times to dislodge Temperature: Betta fish require a stable water temperature between 76°F and 82°F (24°C to 28°C) to maintain good health. Use a reliable aquarium heater to maintain consistent water temperature. Contaminants: Heavy metals, pesticides, and other contaminants may be present in tap water, which can harm betta fish. The Best Betta Fish Tank. Best filtration, best light, perfect size and with everything you need to get started. It was made for Bettas! Buy On Petco Buy on Amazon. Let’s start off the list with the very best of the bunch. The Fluval Spec V has everything you need. Let’s start off with the size of the aquarium. The Penn Plax Betta Fish Tank Aquarium is a strong plastic nano tank with rounded edges. This tank holds 1.5 gallons of water. This kit includes a clear plastic hood with built-in LED light, an internal filter, and a black raised base. The filter can be placed in different parts of the tank based on your preference. Bettas need an aquarium with a filter that is at least three gallons. Before they arrive, set up their new home. How many fish you have will affect the minimum size of the aquarium. The tank should be at least two feet in diameter for a betta. Bettas can live in smaller aquariums, but it is best to have a larger tank for them. Ammonia and nitrites should be at zero, and nitrates should be less than 20 ppm. Bettas need clean water with a pH of between 6.5-7.5 and a dGH and dKH of 3-15. For the self-cleaning tank to have a healthy ecology and function properly, you’ll need the water hardness to remain above 6 dKH and 7 dGH. Therefore, you need to choose the right tank size to mimic their natural habitat. The minimum size tank size for betta fish is 2.5 gallons. However, the recommended size is at least 5 gallons because betta fish need more swimming space. In addition, you’ll need this space to add plants that can act as a filter. A gentle filter, I find, is pretty much vital in any tank, whether it's 1.5 gallons or 20. Without one, you'll have to do water changes of much higher volume and far more often, and not only is it annoying for you, it can be more stressful for your betta to constantly have to be acclimated to new water. This allows betta fish to breathe gaseous air from the surface of the water. You will often see betta fish going to the surface to open their mouths and breathe fresh air. Most other fish can only absorb oxygen out of the water, but labyrinth fish like bettas can also absorb it out of the air. This is why betta fish really don’t need a Lee’s Premium Under Gravel Filter. Lee’s 40/55 Premium Under Gravel Filter is a top-notch choice for anyone keeping betta in a larger aquarium – 40 gallons or larger. They’re made of extremely high-quality plastic – built for durability and prevention of splitting and cracking – and last a long time. LqER.