Spot on top fin of my emerald catfish

Question
Hi Chris,
I purchased an emerald catfish about 2 months ago, to put in with my spotted catfish.  It is just the two of them in my 3 gal. tank.  Just this week, I noticed a small white spot on the bottom tip of the emerald's top fin.  Its hard to see if its puffy, or whether it is just a pigmentation of the fin; however, I don't recall it being there - or being so prominent - until now.  I am guessing it is some sort of disease....maybe ick?  Is there anything else it could be?  Its not a speckle, like some of the pictures I see of ick, but more like one white spot, perhaps the size of 3 pinheads together.  Should I treat the tank with something?  I have an Eclipse 3 tank, with biofilter and hood/light, but no heater.  The water remains about 81 degrees during the day when the tank light is on.  Thank you for any assistance you can provide.  :)

Answer
Hi Linda;

It's probably a wart or scar tissue from an injury or something. As long as it stays small I wouldn't worry about it. If it gets bigger or spreads make extra water changes to help boost your fishes' immunity and help healing. All tanks need a 25% change at least once a week anyway, but two or three times a week would help. Use medication as a last resort. If it gets reddish or looks cottony or fuzzy, that's the time to use antibiotics or antifungals.

If the tank temperature drops more than 3 degrees when the light is off, you might consider adding a heater. It will keep the temperature more consistent. Fluctuations are common in small tanks but they can be dangerous. Parasites such as ich like to attack at times like that.

At Your Service;
Chris Robbins