Hello fishlore. I tested my parameters right now and I discovered a nitrite spike. Im thinking it may be a 1.5 but it could also be in between 2.0 and 5.0. Its hard to tell. My ammonia is at 0 and nitrates are at 15. I have one danio beginning to act weird. Its gasping slightly but still swimming around. However, its beginning to stray from the group. The others are normal. Im about to do a 50% water change. Is this a good course of action? Should I keep this up everyday until the nitrites lower? And will this be really stressful to my danios? I obviously want to save as many as I can. I do not have another tank but I can grab a clean tupperware if it comes to that. Thank you!