Unhealthy pterophllyum....

[AnC]

Hi. I have a couple of angelfish in my tank and it the last two days their fins started to change its color to a color like crimson. Now, they are not very active. They always hide and usually they go to the surface of the water to get oxygen from the air. I think that my aquarium has enough oxygen. What can I do? Help please...

 

[Apocalypse_Gold]

You may have enough oxygen but too much ammonia, high ph, etc. I don't know what test kits are a vailable in Turkey, but see what you can find. In the mean time do several partial water changes.