Please I need help with Molly

[fbm224]

Hello,

I hope you can help me today I found one of my molly (1year old) with red and white injuries, only on its left side. Previously I had noticed a small injure on my white molly but it's still small. All photos I took today, as you can see the other side is fine.

Ammonia 0
Nitrites 20
Nitrates 0
Temp 80.5
PH 7.8

20 gallon high
setup over 2 months
Aquaclear 50

6 molly (3 are 1 year old, the rest is a few months old)
2 swordfish
9 Cardinals
2 rummy nose
15 approx red cherry shrimp

Weekly water changes approx 2 gallons.
last water change 6 days ago
most recent fish have been there 1 month (8 cardinals and 2 rummy nose)

Nothing new, except 1 week without DIY CO2

In the morning I feed flakes and recently started some pellets, and in the evening some gel food.

Thank you !

Edit: It's a planted tank.

 

[aquandrew]

looks like a bacterial infection. brought on by poor water quality. sorry to say but 20 gallons isn't nearly enough for all those fish and 2 gallon water change is barely anything. to heal this you are going to need to do daily water changes of at least 5 gallons until it heals. do you have your nitrates and nitrites mixed up? nitrites should be zero

 

[fbm224]

looks like a bacterial infection. brought on by poor water quality. sorry to say but 20 gallons isn't nearly enough for all those fish and 2 gallon water change is barely anything. to heal this you are going to need to do daily water changes of at least 5 gallons until it heals. do you have your nitrates and nitrites mixed up? nitrites should be zero

Yes I mixed them up, nitrate is 20, nitrite is 0.

Is there anything else I can do besides the larger water changes?

Thank you,

 

[Platiesareawesome]

Yes I mixed them up, nitrate is 20, nitrite is 0.

Is there anything else I can do besides the larger water changes?

Thank you,

Welcome to AA!

I have to agree, your tank looks pretty overstocked to me. If I were you, I would be doing 50% (10 gallon water changes) weekly regardless of the bacterial infection because your tank is so heavily stocked. 5 gallons daily is fine, like aquandrew said until the infection goes away, I think. (Although, I know just about nothing about how to treat bacterial infections! ) You may want to look into re-homing some of those fish. (I know how it feels, I had overstocked my 10 gallon tank with 3 balloon mollies and I had to give them back to the pet store, and I still miss them! )

 

[fbm224]

Thank you Platiesareawesome,

I have just made the second water change, and she looks a little better today, less red and more animated.

I'll think hard on how to reduce the stock, to be honest when I bough the cardinals I expected a high death rate due to a bad past experience, I expected 4 or 6 to survive, but all of them did .