My bumblebee gobies have lost their brilliant yellow color over the last couple weeks since I bought them and one of them is now see-through (ie clear) where its yellow bands used to be and I'm not sure why.
They are the freshwater tolerant variety and I am keeping them in a freshwater tank. They get fed live blackworms every other day and eat them with vigor. I do 30% water changes once a week. I had 0ppm on ammonia, nitrites, and nitrates with a pH of 7.4 before my last water change. I have a slow current in the tank so they don't get agitated and so the sand doesn't get kicked up. The water is filtered through activated carbon and a strip of the Poly-Filter chemical filter. The temp is at 78F.
Does anyone have any ideas on what is going wrong? I know there is much debate on whether or not they need brackish water. Will this help their coloring? I bought them as freshwater and they were brilliantly yellow. I have heard of many other people keeping them in strictly freshwater and having them thrive.
Thanks in advanced.