I woke up this morning to quite the scare. Two of my lemon tetras were wedged in between the sponge of the sponge filter and the glass. I thought for sure they were dead, so I grabbed my net and moved the sponge. To my surprise they both swam out as if nothing had happened, which was a huge relief. I went to class and when I came back, another tetra was wedged the same way the first two were. This one also swam out once I moved the sponge. All of the fish are fine and swimming around like they usually do. I tested my water to make sure everything is fine and I have 0 nitrite, 0 ammonia, and 10 nitrates. The pH hasn't changed from 6.8 and the temperature is still 77 degrees. I just finished feeding them and all of them aggressivly ate the food like they usually do. Not sure why they wedged themselves the way they did, but I am praying that it doesn't happen again while I am away at work for the rest of the day.