Hey guys, just had a question. My 3 platys used to swim at the middle/top of my tank, but recently, about 4-5 days ago, they started hanging out at the bottom of my tank, hiding in the plants. Is this a sign of something wrong? My parameters are 0 ammonia, 0 nitrite, and 10-20 nitrates. They also used to feed like crazy, always going for food at the top of the tank, but now they seem to just feed on the bottom, after the food sinks. I have been leaving the light on for 8-10 hours, but there are some floating plants and what not.