Brown water in tank

[Sloth]

Hey everyone,
I've had my axolotls for about a year now and the water has pretty much always had a brown tint to it. I have a 40 gallon tank with only 2 axolotls in it and the ammonia and nitrate levels are always pretty low. There isn't usually a lot of **** on the bottom of the tank and no driftwood in there either.
The Axolotls don't seem to mind, both look healthy and eat fine just looking to make the tank prettier. Sometimes water changes help and sometimes they make the tank more brown which really does confuse me so I'm not really sure what to do.
Any ideas?

Thanks

 

[Donna001]

Hi there.
Would you be able to post some pictures of your tank?

 

[Blackbun]

Hello Sloth, is the brown after clear (suggesting dissolved chemicals) or cloudy (suggesting particulates such as brown unicellular algae)? Agree with Donna, an image would be most helpful.