I just pulled a bunch of hornwort out of my tank to put it in another and I was able to get a good look at everyone. I noticed one of my tetras is looking not good compared to the rest. It looks like his tail is almost gone and he's having a hard time swimming, there is a sponge on the HOB intake so they can't get stuck. I've had them for 7 months now. Only thing in the tank is harlequin rasboras, three types of snails (bladder, rams and trumpets) and I added 5 neo cherries about a week ago and planning on adding another 5 or 10 soon. Ammonia and nitrites 0 and nitrates stay steady around 10. I do weekly wc of around 25%, temp is a constant 78°.