Fin Rot Overnight?

[arix]

Hi everyone. I have a betta who I've owned for a few months now. I had been keeping him in a 2 gallon tank and he was thriving. However, I wanted to give him a bit of an upgrade so I moved him to a 10 gallon tank with a filter and heater. I had had a different betta in it previously but did a probably 90% water change before putting in little Shogo. The previous betta had never had any problems and he was in the tank for over a month. He had been in the tank about 4 days and I'm noticing a rapid problem with his fins. I attached some photos though the last 3 he didn't exactly want to cooperate with me taking pictures. He was in a small container for those three because I really wanted to get him out of the tank, as the issue appeared to get a lot worse from when I saw him before my morning class.

I guess what I want to know is, is this fin rot? Should I not put him back in the 10 gallon tank? What could have caused this etc.. I feel so bad for my little guy ): I was worried to put him into a new tank because he was doing so well in the old one.

Housing
What size is your tank? 10 Gallon
What temperature is your tank? 79 degrees
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? One Ghost Shrimp.

Food
What type of food do you feed your betta fish? TetraBetta or Aqueon Betta food.
How often do you feed your betta fish? 2 tetra betta pellets a day or a pinch of the aqueon pellets (they're pretty small)

Maintenance
How often do you perform a water change? 10% 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?

Water Parameters:
Have you tested your water? If so, what are the following parameters?
Have not, will go out and buy a kit if necessary.

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

Symptoms and Treatment
How has your betta fish's appearance changed? Tail seems frayed (almost like a crowntail)
How has your betta fish's behavior changed? Hasn't really changed.
When did you start noticing the symptoms? Yesterday I noticed a small rip in the fins and this morning is was worse, after my classes it seemed even worse.
Have you started treating your fish? If so, how? I have moved him to a 1 gallon tank with the reccomendation of 1 tsp of aquarium salt.
Does your fish have any history of being ill? No history of illness
How old is your fish (approximately)? I've owned him for several months (not sure how long..)

[Oldfishlady]

I can't tell by the pic if its rot or not, however, most likely the cause is the filter and/or the use of the Long delicate fins to swim in a larger space- Once the fin tattered-this caused an opening in the tissue and a secondary infection-then the added stress-both can compromise the immune response.

Some, not all, Long fin male Betta-can have problems with filters and/or space-somewhat like the flag in the wind effect.

I would go ahead and do a fresh/dechlorinated water and tannins with improved nutrition treatment for 7-10 days in a smaller unfiltered tank or QT and see that help any. Or just move him back to his 2gal-provided that he doesn't have behavior changes along with the tattered fins. If he is otherwise acting his normal self-keeping the water clean and adding tannin-along with good nutrition-his fins should heal up and start regrowing within the week-more or less...

[arix]

Thanks for the reply. I'm definitely going to keep him in a smaller tank while he heals up. Would you not recommend putting him back in the 10 gallon after he has healed? If I did I would probably remove the filter and just do 20% water changes weekly instead of 10%..

I'll try to post another picture (With better detail of his fin) when the bubbles have cleared in the tank.

[arix]

A few more pictures:
The first is of how his fins looked about 3 days ago and the second is how they look now (hopefully a better picture than the last few, tricked him into thinking he was getting more pellets today)

[callistra]

Cycling a new tank can take up to two months.. several weekly water changes will be needed during cycling or fin rot almost always surely happens: http://www.bettafish.com/showthread.php?t=47838 Even when fully cycled 25% weekly minimum with siphon will be needed.

The filter can just be prefiltered so that it can't catch his fins: http://www.amazon.com/s/ref=nb_sb_no...ords=prefilter It may also need a sponge baffle on the outflow if you feel the current is too strong for him.