30 gal tank, two freshwater iridescent sharks (only), nitrates ~20 nitrates ~.5 PH 7.2. Last water change about a week ago.
Fish are about 6 years old. They've been doing good lately, no fin rot. Active and eating regularly.
I noticed that one of them has been getting lighter (less black colored). Usually that happens when they have some immediate stress like panic from being cleaned. The last couple years they have been more curious than worried when I clean them and they don't panic or even mind the process.
I was not too worried but I noticed today that the lighter guy was spending some time sleeping on the bottom. They had a couple years where they did that a lot, but the last year they've been up 24/7.
When I fed them he woke up and came to eat but I see that his body looks reddish brown all the way around the gills/main area and also along his body towards his tail. He may also be losing weight although that's hard to judge. He has certainly been eating well... they are always ready to eat.
I don't know if the reddish-brown is just his internals showing through because he's become so "clear" in his body or if he's got some strange illness I am not familiar with.
Thoughts?
Fish are about 6 years old. They've been doing good lately, no fin rot. Active and eating regularly.
I noticed that one of them has been getting lighter (less black colored). Usually that happens when they have some immediate stress like panic from being cleaned. The last couple years they have been more curious than worried when I clean them and they don't panic or even mind the process.
I was not too worried but I noticed today that the lighter guy was spending some time sleeping on the bottom. They had a couple years where they did that a lot, but the last year they've been up 24/7.
When I fed them he woke up and came to eat but I see that his body looks reddish brown all the way around the gills/main area and also along his body towards his tail. He may also be losing weight although that's hard to judge. He has certainly been eating well... they are always ready to eat.
I don't know if the reddish-brown is just his internals showing through because he's become so "clear" in his body or if he's got some strange illness I am not familiar with.
Thoughts?