lionhead goldfish

Question
Hi Chris, I have had my tank set up for over 2 1/2 years, it is a 40 gallon, I have 1 lionhead, 1 black moor, 1 oranda and 1 fantail fancy goldfish.  I just noticed that Zepplin (lionhead) had a couple of black spots on his/her head. Good appetite, swimming fine, all other fish are finek ph/ammonia levels are fine, I do a partial water change weekly and clean the gravel. I do a full cleaning once a month.  I have not had this problem before, Is this normal for pigment to change or do I possibly have a problem?

Answer
Hi Karen;

Goldfish do change colors over most of their lives so it could simply be new color developing.

Black on fish can be from ammonia burns too so check the ammonia levels more often, especially a couple of days after cleaning, just to be sure they aren't "spiking". Ammonia is essentially fish waste. Goldfish are very messy guys so ammonia can be a chronic problem in their tanks when everything seems to "look" okay otherwise. Your fish have probably grown and become messier over time too. Test for ammonia every day for a while to see how it is going. Keep up with weekly 25% water changes and gravel vacuuming and avoid overfeeding to help keep ammonia from ever being a problem.

If by a monthly "full cleaning" you mean draining the tank and cleaning filters and everything, it really isn't a good idea to do that. It kills too much of the beneficial bacteria that actually consumes fish waste, so ammonia will rise for a few days after that until the system stabilizes again. Just the weekly changes and vacuuming should be enough. If your tank gets dirty in spite of weekly cleaning, cut back on food. You could even do partial changes twice a week to keep it under control.

At Your Service;
Chris Robbins