I have been overrun in my tank with algae even on my live anacharis, so I bought a thing of API algaefix to help me get in under control. Dosed it according to label directions a few days ago. That first night a few hours after I dosed it my fish were lethargic and no one wanted to eat. (I had also bought some seachem Purigen and stuck it in the filter, then i read that it was for 100 gal and this is a 20 gal tank so i took it back out. Not sure if that is relevant?). The next day everyone seemed a little better and by yesterday everyone seemed back to normal. Tonight one of my loaches can’t swim and seems to be having seizures, I’m probably going to have to euthanize him as his body is bent weird behind his head and Im so upset watching him suffer. Could the algaefix have caused this?? I forgot to test water parameters tonight but I will in the am. All the other fish seem just fine.