Condy anonome turning brown

How come i have 0 nitrates and my anemone is turning brown? :-/

 

idk, but your nem is turning brown because it is getting healthy..

what color was it when you bought it??? white???

 

I'm guessing you have 0 detectable nitrates, because you couldn't have much living in your tank if you really have 0 nitrates... 0 nitrates just means your nitrate is low enough it can't be detected by your kit, or it is being consumed as soon as it's produced. (Actually, I should really say inorganic nitrogen, not nitrate, but nitrate is probably the most available form so, yada, yada, yada...).

Anyway, so, I guess really the natural color of an anemone is the color when it's bleached. The color you see however, is also influenced by the color of pigmentation, such as fluorescent protein, or is the color of the zooxanthellae. Both are products of a healthy anemone. There really isn't ubiquitous pigmentation in a condy, so, this is mostly the zoox. So, assuming it isn't bleached, the color of the nem, will be based mostly on the color of the zoox and the color saturation will be based on the density of that zoox within the tissue. In a non-bleached coral/anemone, the density of zoox in the tissue, assuming no change in light level, is directly related to the available nutrients, but IIRC experiments suggest it tends to be mostly N not P limited. So, for a condy, N -> zoox growth -> browner nem.

It seems that a condy can be pretty white, with just a hint of brown and still be healthy (not bleached). Being bleached indicates it is unhealthy and there's a ongoing expulsion of zoox that will lead to death if not reversed.
So, Going from bleached -> brown = good
Going from very light brown -> darker brown probably good, may not be necessary for survival, but ensures the nem should have sufficient nutrition to deal with stressors.
Going from darker brown -> darker brown is either acceptable, or bad. If the nem can handle the zoox byproducts, it's fine, however, if it looses control of the zoox, the byproducts can become a stressor and lead to health issues such as bleaching.
This seems to be pretty much why people say to keep nitrates low. The nitrates themselves aren't particularly toxic, but the fueled zoox growth could be.

anyways, sorry if that was superflous.... I think assuming brown = good is probably fine 90% of the time, I just wanted to point out there are exceptions if nutrients availability is too high.