Angelfish bruise-like thing on head

[YunoGasai212121]

I have an angelfish her name is yuno and she has this bruise like mark on both sides of her head that seems to get darker when she’s stressed and lighter when she’s eating and not stressed. It changes color within seconds. It doesn’t look like it’s a stripe or like it should be there. There is two other angelfish in the tank male and unknown who have been picking on her but even when my angelfish were separated she had to spot. She also has a little trouble swimming where the filters current and leans to the left a little but she swims normal at the bottom of the tank and when she eats. If anyone knows what the bruise like thing is it would be greatly helpful.

The tank should be really clean since it’s new. I put in 5G old water because my brother said something about bacteria. I let it cycle threw for like 5 days.

Tank info:
Tank size: 29G (it’s a new tank)
Tank temp:79F
Fish symptoms: blue/black bruise thing on head behind the eyes on both sides that fades/darkens instantly. also leans to the left while swimming.
Water changes: haven’t changed the water yet because it’s brand new and they went in 6 days ago.
Chemical additives:none
Tank inhabitants: 2 other angelfish the same size that have been with her for 5 months.
Plants: plastic plants
No exposer to chemicals

 

[Colin_T]

Can you please clarify how long the tank and filter have been set up for and how long have you had the fish for?

My understanding is this is your second tank that was set up 6 days ago and you had 2 other angelfish for 5 months that were presumably in another tank?

----------------------
Can you check the water quality for ammonia, nitrite & pH and post the results here?

----------------------
Did you move the old filter from the other tank onto the new tank?
If no, then you will not have any beneficial filter bacteria in the filter to keep the water clean and you will have to monitor ammonia and nitrite levels closely for the next month or so. You should also reduce feeding to once every 2 days and do a 75% water change and gravel clean the substrate each day or any day there is an ammonia or nitrite reading.

If you still have the old tank running with a power filter, you can take half the filter media from the old filter and put it in the new filter and that should give you an established filter with the good bacteria that will keep your water clean and free of ammonia and nitrite. But you will still need to monitor these levels for a few weeks to ensure the filter materials are working.

There is more information about filters and filter bacteria at the following link.
http://www.fishforums.net/threads/cycling-your-new-fresh-water-tank-read-this-first.421488/

----------------------
Depending on how long the fish has had the black mark for, and how long it has been leaning to one side will determine the possible cause. If the fish has had the black mark for months or since you got it, then the mark is probably colouration. Fish have night colouration, which is usually darker than day time colouration. Stress colours are similar to night colours and the fish are usually darker.

If the black spot appeared recently, in the last few days, then it could be a bruise from rough handling, or chemical burns, possibly from chlorine/ chloramine in the water, or ammonia, nitrite or nitrate in the water.

The fish leaning to one side could be brain damage or just too much water movement for the fish. If the fish regularly sits on a funny angle and has done so since for months, then it was probably damaged when young or has a genetic defect that causes it to sit on a funny angle.

If the fish only does it when swimming into a strong current (like that from a filter) then it is probably the water movement and the fish is struggling to swim against the current.

If the problem is brain damage or a genetic defect there is nothing you can do and I wouldn't worry about it. If it's caused by too much water movement then put something in the way of the filter outlet or redirect the outlet so there is less water movement and more quiet calm areas for the fish.

----------------------
If the other 2 angelfish are picking on the third angelfish, then the 2 bullies could be a pair (male & female) and are trying to drive the third fish out of their territory. Monitor them over the next few months and if it gets worse, move the third fish into a different tank.

 

[YunoGasai212121]

Thank you for your reply.
The filter should probably have good bacteria in it because I took my dads 29G filter from his tank that’s been set up for a while and put it in my filter.
Also what is a nitrite?

 

[Colin_T]

Anything (fish food, fish waste, dead plants & dead fish) that breaks down in water releases ammonia. This is eaten by beneficial filter bacteria and converted into nitrite. There are different bacteria in the filter that eat nitrite and convert it into nitrate. You do water changes to dilute the nitrates and remove them from the tank.

Basically bacteria eat ammonia and convert it into nitrite, and more bacteria convert nitrite into nitrate. This is referred to as the filtration cycle or the nitrite cycle.

 

[YunoGasai212121]

Oh okay thanks. I’m noticing that I think one of her fins that helps her swim in the from is torn and not working as well and that might be why she’s swimming side ways cause the other ones working better. Is that going to be a problem?

 

[Colin_T]

a damaged pectoral fin won't cause the fish to swim on a funny angle.