Hello! I’ve recently cycled a 16 gallon tank and I’ve had an established 5 gallon tank for a few years now, last Saturday I did a water change which is usual about every other week or so and both of those tanks spiked up with ammonia right after and I’m just wondering why, in my 5 gallon tank I had a pea puffer but I had to remove it due to the spikes and it not doing well at all, I think it might die, I have a 29 gallon tank too but that seems to be going fine. Does anyone have any ideas on maybe why I’m having ammonia spikes?