My betta is sick. I'm not sure if it is velvet or ich. What's the difference? How do it treat it? I'm making daily partial water changes in case it's because of bad water quality. It's in about 15 liters of water. Another little question: Can methylene blue be purple?? I had checked a couple of pharmacies but all methylene blue i'm getting is purple. Only aquarium medecines are blue(and more expensive). Is that normal? Thanks 