I just wanted something a little bigger than the Serpae tetras. I will of course keep my common pleco, he is probably my favorite because I have had him for so long. I had about 9 neons a while ago, then, about 3 weeks ago, I added 10 more, bringing my total up to 19. Everything was fine for about a week or so, and then little by little, I noticed them disappearing. Now there are about 7 which is the same number for about 2 weeks. I checked everywhere, and I didn't see any except one which I scooped out. I checked my water and everything was fine.