Yellow Spot on Tailfin?

[turtlephobic]

Hello! Today while I was taking picture of my fish, I noticed on his tail he had this dull yellowish spot on it. I can't tell you how long its been there since I just noticed it. Other than the spot, he's acting like his normal grumpy self. Is this just part of his coloring or something else?



Sorry if the picture is too big.

Housing
What size is your tank? 10 Gallons.
What temperature is your tank? Around ~77 degrees F.
Does your tank have a filter? Yes.
Does your tank have an air stone or other type of aeration? No.
Is your tank heated? Yes.
What tank mates does your betta fish live with? He's alone.

Food
What type of food do you feed your betta fish? Omega One Betta Buffet. (I can't get him to eat pellets to save my life.) Omega One Freeze Dried Blood Worms as a treat once a week.
How often do you feed your betta fish? Once a day, normally around 3:00 - 4:00 o'clock.

Maintenance
How often do you perform a water change? Weekly.
What percentage of the water do you change when you perform a water change? 10%.
What type of additives do you add to the water when you perform a water change? I used to add Top Fin Water Conditioner, but it recently expired so I haven't done a water change lately. I can't get a new one until Wednesday.
About a week ago I had a Algae Bloom, so I went out and bought a tank scraper (Rinsed several times before using) and Tetra Algae Control. I put Eridan in a temporary home while I cleaned the decorations and the tank walls.
Water Parameters:
Have you tested your water? If so, what are the following parameters? n/a

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? Yellowish spot on the bottom left side of his tail fin.
How has your betta fish's behavior changed? It hasn't.
When did you start noticing the symptoms? Just about ten minutes ago.
Have you started treating your fish? If so, how? No.
Does your fish have any history of being ill? No.
How old is your fish (approximately)? I got him on July 30th of this year, so about 4 months give or take?

Thanks for the help! :D

[Pataflafla]

It could very well be his natural coloring.

When you can get a water conditioner, up the weekly changes just a little bit to see if it's something to do with water quality or not.

[EvilVOG]

keep an eye on it. Velvet will show like gold sparkles on your fish.

[Pataflafla]

Originally Posted by EvilVOG

keep an eye on it. Velvet will show like gold sparkles on your fish.

I don't think it's velvet. Velvet looks like a finer gold sprinkling (Almost like ick).

Most bettas do have gold/yellow iridescence that shows in certain lights however, so it could be that.

Do keep an eye on it, but it's most likely nothing to worry about since behavior hasn't changed at all.