Hello there again! I'm wondering if my fish are suffering from possible stress, and if so, from what? After the death of the 7th neon tetra (now there's 6 remaining), they've been hiding in their little spot since then. What I've noticed is that ALL of them had their colours fading and their heads had this golden/green colour, as well as minimal appetite. It could possibly be velvet, though I wasn't inclinded to assume it since I thought it would also appear on its body, which it hasn't. I have checked the water quality and apart from the nitrates, at 60 PPM, both ammonia and nitrites are at 0 PPM. So I deduced that water wasn't the problem, and that it's likely that there's too few neon tetras in the tank?