I have 4 red eyed treefrogs that are currently living quite happily in an a tank with a central water dish (and three living plants + 2 fake ones) but i wanted to upgrade to a larger water resource my idea was to bury a large container in the substrate so the water was level with the ground, than add gravel (so the frogs could sit in it) and a filter.Please!! Notify me about any flaws in my idea or give any of your Ideas because im open to suggestions

Thanks