IDK what is going on, I've tested my water and all stats are withing normal range, but to be on the safe side I did a 25% water change. Now I have at least 2 females giving birth so IDK if that is why all of my fish are crowding into the corners of my tank? Usually when I do a water change they love it and come springing to life but not this time, IDK why all of my fish are at the bottom, I did find a stink bug floating in the water and have since removed it and done a 25% water change, as of right now there are only 4 out of 15 fish swimming around the whole tank as usual...someone please tell me what is going on, I really don't want to lose my fish! The tank is 60 gallons and has been set up for quite some time btw