I read several posts on this "red bump on head" that were several years old.
I have had a regular goldfish for about 3 years. He looked lonely, so I went to WalMart and bought an algae eater and another regular goldfish. Two days ago, overnight, this red bump appeared on the large regular goldfish.
I admit the tank was dirty, about a week. I don't have filters or pumps hooked up, I just change the water in the 5 galllon tank once a week. Never had a problem before.
I first suspected and injury, since nothing else had changed. Then read several forums about bacteria, wens, dirty water, etc. I had been putting a dime sized tablet of "algae food" everyday for the algae eater....so the water was extra dirty.
I saw a post about a picture and here is mine: goldfish MooPig
The bump is definitely under the skin right between the eyes. He is very healthy, active and eats a pinch of fish food twice a day. In all respects he is ok, except for this "red bump".
Help ! I don't want to douse the tank with ( light gravel bottom and some glass beads) chemicals unless I have a better idea of what this is. I hope it is just a Wen...
Thanx and MooPig thanx you too.