+1. Ammonia is poison so will harm any so called hardy fish it's like us breathing toxic air, you may be able to survive but it will shorten your life and lead to health issues later on.
Not teaching my wife and kids how to look after the tank or what to do in an emergency.
I was working late one night and when I got home heard a disturbing bubbling sound. The aqua stone had come off the end of my co2 injection system and was happily bubbling away. I lost half my fish to co2...
And here is her fellow furry. 35 kg of 8 year old black lab that she basicly is in charge of because he is so soppy. The cat is 3kg so that's a massive size difference.
I have come across somthing called "pre filter sponges" online.
They sound like a good idea.
Anyone have experience with these?
https://www.aquariumcoop.com/blogs/aquarium/pre-filter-sponge
Lots of advice here to never use filter media belonging to someone else.
I beg to differ as I have donated lots of mature filter media over the years to help with cycling a newbies tank.