I went to say hi to my little buddy lastnight and noticed a strange, rather large, clear... thing. It looks like a giant scale. Also, this light discoloured patch on his head is very new. He had just eaten there so his belly is a bit pudgy. Is this something to be worried about? no ammonia, no nitrite, nitrate can't possibly be high since I did a gravel vac/water change less than a week ago. water is fairly neutral, dipping into slightly acidic. If you need any info just ask...