Zebra Danio Washed Out Colour And Over-active/aggressive

[ZoddyZod]

Hello,

Not sure if this is an emergency, but I've just noticed that one of my 11 zebra danios has changed colour. The usual colour appears to have washed out slightly and now the normally silver/white areas are a faint pinkish colour. He is also much more active than normal and appears to be harrasing the rest of them.

I am a week into a first cycle, readings are

Amonia (dont know, just off to buy some more testers)
Nitrite 0
Nitrate 40

Did a 20 % water change yesterday.

 

[ZoddyZod]

Scrap that, he's more of a yellow colour. I've just read elsewhere that this may be 'display' colours and the spawing is quite aggresive with the species.

Several others have changed colour now as well. Getting rather fiesty in there!

can anyone confirm?

 

[WILDER]

Not good cycling with fish as it takes it toll on them.
It burns there skin and gills.

Buy an ammonia test kit in liquid form.

How many gallons is the tank.
Do you only have danio's in the tank.
If so increase aeration and add some salt.

 

[ZoddyZod]

Not good cycling with fish as it takes it toll on them.
It burns there skin and gills.

Buy an ammonia test kit in liquid form.

How many gallons is the tank.
Do you only have danio's in the tank.
If so increase aeration and add some salt.

It's around 27 Imp gallons.

Only the Danios in there

Aeration is very good (use a Fluval U3)

Pretty sure it was a mating display. The slighty fatter fish (females) have not changed colour and the smaller males are doing all the chasing. Has settled down a bit now.

 

[WILDER]

Get a jug and fill the jug would tank water.
Add two tablespoons of salt and stir well to the salt disolved. Add the water back to the tank.
Salt helps fish in a cycling tank.
Don't add anymore fish till the tanks cycled.