Help! Lethargic Betta, Serious Fin Damage,

Hello,
Could you guys help me figure out what's wrong with Speck, my betta? I'm really scared about her.

Last week, I noticed she was having trouble swimming, she was having trouble keeping her tail up when she swam, and was resting more than usual. On Wednesday, I decided to fast her, and on thursday i left for a trip. I had a friend feed her a little bit on Sunday. I got back Monday, and Speck had a big chunk out of her tail, a piece out of her anal fin, and still couldn't swim normally!


Housing
What size is your tank?5g
What temperature is your tank? 78F
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? none

Food
What type of food do you feed your betta fish? NLS and freeze dried (soaked)
How often do you feed your betta fish? 2X a day.

Maintenance
How often do you perform a water change? 1X a day.
What percentage of the water do you change when you perform a water change? 50%
What type of additives do you add to the water when you perform a water change? dechlorinator and I started adding Seachem Stressgaurd yesterday.

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia: 0
Nitrite: 0
Nitrate: It was 10.0 yesterday (I was on a trip this weekend)
pH: 8.3
Hardness:
alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? Big chunk out of her tail, piece missing from anal fin and small piece out of pectoral fin. The tip of one of her ventral fins are red. Also, (not sure if this has anything to do with it) the top of her caudal peduncle has no color, I thought it was just coloration but maybe it's an infection or something. I have a picture.

How has your betta fish's behavior changed? Difficulty swimming, she has to rest a lot. Maybe heavy breathing I'm not completely sure though. She's still wants food and tries to "dance" but she sinks.

When did you start noticing the symptoms? Before I left, she was having trouble trouble swimming, (sinking) I left for a trip on Thursday and returned yesterday and she had a big chunk out of her tail. She also has a tattered pectoral fin which has a bit of red in it, red tip on her ventral fin, two small chunks out of her anal fin.
Have you started treating your fish? If so, how? Daily W/C (should I increase to 2X a day?), turned off her light and a 1/4 cap of Seachem Stressgaurd daily.
Does your fish have any history of being ill? no
How old is your fish (approximately)? I bought her as a baby over 2 months ago.

So, I'm not sure if it's tail biting and if it's finrot it's the scariest case I've ever had! Does anyone know and what should I do?? Thanks 

Hi fiddlefish,

Just a thought i've had while reading your thread, if she is having trouble swimming and keeps sinking, is she able to reach the surface to breathe ok?  If not you may need to think about providing a perch or something so she can rest near the surface.(I don't know your tank layout so forgive me if you have this covered!)

I really hope you can treat her and she gets well, losing a betta is soul destroying as they are such beautiful little characters.

Best wishes,

FC76

Hi fiddlefish,

Just a thought i've had while reading your thread, if she is having trouble swimming and keeps sinking, is she able to reach the surface to breathe ok?  If not you may need to think about providing a perch or something so she can rest near the surface.(I don't know your tank layout so forgive me if you have this covered!)

I really hope you can treat her and she gets well, losing a betta is soul destroying as they are such beautiful little characters.

Best wishes,

FC76

Hi!
Don't worry, she is getting to the surface quite easily, thank goodness. She also has a floating log that she loves.
And yes, losing a betta is horrible, I've already lost 3 in the past year and am not ready to lose another.

                               

Okay 
I'm asking for help with this on some other forums maybe they'll know what type of meds I need. We'll see... Hope she gets better. She still has a will to live (and for food).

A shop that sells fish should also sell antibiotics for fish. I know that Americans talk about gram positive and gram negative bacteria and the need to get the right kind of antibiotic; I have heard of Maracyn 1 and Maracyn 2 in the USA but I have no idea which one is for gram negative or positive I'm afraid.