The last of my original fish from my first aquarium I started last July is now dying. It was a 40 litre tank. On this forum I learned that I'd been given much misinformation by my LFS and elsewhere online about water changes. I'd only been changing about 20% every 2-3 weeks. I've been told here that m fish are most likely dieing from the effects of an ammonia spikes. From the pics, would people agree? Have since started a bigger 90 litre tank. Would people agree that a weekly water change of 50% is best. Or more like 20% weekly? Thanks.