Hi! We started a new 20 gallon tank 9 weeks ago using some water from a previous betta tank. After 2 weeks, the tank was cycled (0 ammonia, 0 nitrites, 5-10 nitrates). Next, we added 3 guppies, 2 gold panda mollies, and 5 cherry barbs. About 10 days later, the water turned cloudy and green...