I only have 4 fancy guppies, 2 mystery snails, 3 ghost shrimp, 2 tetras, and 1 chinese butterfly loach. I have 12 baby guppies which are about 1 week old. My tank is 29 gallons, and its been running for 4 weeks. I only feed my fish every other day and the babies get liquid fry food 3 times a day.