Fin Rot already?

[Miko Hayashi]

I got a new betta fish. Actually, I have two. They're in separate tanks. My female veiltail Natasha has a nice looking tail and fins. She's doing fine. My male deltatail Tom is having problems. It's weird! His bottom fin is curling slightly and he already has a small tear on his tail fin.

This is his housing specs and such.

Housing
What size is your tank? 3 gal
What temperature is your tank? 80F
Does your tank have a filter? No
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? None

Food
What type of food do you feed your betta fish? BettaMin Tropical Medley fish flakes
How often do you feed your betta fish? A couple of flakes about 3 days a week.

Maintenance
How often do you perform a water change? once a week
What percentage of the water do you change when you perform a water change? 25%
What type of additives do you add to the water when you perform a water change? Just a simple tap water conditioner (API Tap Water Conditioner)

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? Small tear in tail. Bottom fin edges are starting to curl.
How has your betta fish's behavior changed? No. As spastic as ever and blowing bubble nests!
When did you start noticing the symptoms? About a week ago.
Have you started treating your fish? If so, how? Started using a little bit of Maracyn II. Less than 1/8th a teaspoon.
Does your fish have any history of being ill? No
How old is your fish (approximately)? I can only guess about 6 months.

The odd thing is Tom and Natasha have the same kind of water with the tap conditioner and I've had Natasha longer. Her tail is perfectly fine and her behavior hasn't changed.

[shellieca]

Do you have hard water? My VT's have some curl on their fins & I've been told it can be from hard water which I have. As for the tear, could be a decoration, plant, the filter. Can you post a pick? I don't usually worry too much about minor tears but I do keep a close eye on them to make sure they don't get worse or turn into fin rot.

[Miko Hayashi]

I don't have a very good camera but it's a minor tear. I do have hard water. I live on an aquifer and we don't have filtered water so it always has a lot of minerals in it.

[shellieca]

Make sure there's nothing in your tank causing the damage. As for the curl, I'd blame your water & there's not much you can do unless you soften your water. I wouldn't try to adjust it as that can cause problems in itself.

[Miko Hayashi]

I'm keeping an eye on it!

[Viva]

The fish could have fin rot from being in a dirty cup for too long at the store too. I always like to treat my new, long-finned fish with some aquarium salt when I first get them just in case their is some fin rot starting.

[Miko Hayashi]

I should have added aquarium salt before I put him in the tank.

[callistra]

He probably came in with a slight infection, however you're not doing enough water changes. A lot of people will tell you not to even bother trying to cycle something this small, but you can try. You will always need twice weekly 50% with siphon or turkey baster, but while it's cycling you should be testing daily for ammonia and nitrite and doing an extra 50% change any time you see either show up: http://www.bettafish.com/showthread.php?t=47838

He should be getting two small meals a day, at least a couple at a time and one fast day a week. However, flakes are low quality and they muck up the water quickly. You should look for a pellet whose first two or three ingredients are whole fish and not fish meal or wheat.

Maracyn II will also toast your cycle so whenever you're doing with that you'll have to do a full water change and start over.

[Miko Hayashi]

I should look into a different kind of tap water conditioner. What would you guys recommend?

[LittleBlueFishlets]

Your water conditioner (API Tap Water Conditioner) is fine. You need to do more frequent water changes, though. You are only changing 25% per week, and you have no filter. It's likely that the ammonia and waste levels are high in your tank.

The water change recommendation for a 3 gallon tank with no filter is one 100% and one 50% water change every week. That said, if you have live plants, the recommendation would change since they would utilize the ammonia as fertilizer. Here is the water change recommendation thread: http://www.bettafish.com/showthread.php?t=115758

It's not necessary to add aquarium salt. Bettas are sensitive to salt. Using it for long periods of time can harm their kidneys. I would try keeping him in clean water, without added salt, and seeing if the fins heal.

Also, I agree with Callistra's food recommendation. Look at the ingredients on the food container. The first several ingredients should be fish proteins. If they aren't, consider getting a higher quality food. The two more frequently recommended foods on this forum are New Life Spectrum (NLS) pellets and Omega One Betta Buffet pellets.