I have had bettas for several years now and have never had a problem (except one of them got constipated) but I just got a new betta and his bubble nests are orange. I thought at first it may have been a problem with the water, but I've changed his tank 3 times and each time he makes a nest it has orange bubbles. I've googled TONS of different things trying to find out what's wrong but can't seem to find anything. There is nothing visibly wrong with him, he swims and eats fine. Any ideas as to what might be wrong?