This low profile, 3D printed lid was mainly designed to help keep cat paws out of the aquarium. It has a snug, secure fit. The air / feeding holes are conveniently located. The center voided area allows for maximum LED light transfer. Lastly, the holes are large enough to accommodate plant stems / cuttings such as Pothos that will root within the water and provide extra biological filtration for your Betta fish.
Besides weekly water changes, plants are the safest and most effective way of eliminating the nitrates from the water. Plants feed on the very same nutrients as algae. Plants remove nitrates and phosphates from the water leaving less for the algae to consume.