So my fish Peri died. And like often when a fish dies, the ammonia in my tank spiked. It is currently at .25-.50 pmm. This is a hard water African cichlid tank, and I just did a water change. I currently have one penguin 350 running on it, and 9 2-3 inch peacock. It is 3 months old. How should I get the ammonia down?