Thanks for the help guys!
I’ll get the sponge soaking ASAP, and I might put a bag of cycled media in the tank to help out. Doesn’t rlly matter too much where the bacteria is if there’s water flowing past it, right?
I’m probably going to go with a simpler and more handy solution than the pat mini; I found a cheap air pump I can hang above my tank, that is easily powered by a regular phone charger. Comes with air stone, so will use to quieten the filter.
https://www.ebay.com.au/i/133235983143?chn=ps&norover=1&mkevt=1&mkrid=705-139619-5960-0&mkcid=2&itemid=133235983143&targetid=677698376112&device=m&mktype=pla&googleloc=9071445&poi=&campaignid=7418917127&mkgroupid=84562536687&rlsatarget=aud-693796249881:pla-677698376112&abcId=1139436&merchantid=7364522&gclid=Cj0KCQiA89zvBRDoARIsAOIePbC4pTWIYe7sEHPWYsEMM9ZJLAsOweAJreSSQ7N7RmO-FK414LmFWIsaAhfKEALw_wcB
It is said to be very very quiet.
With luck, I should have my new fish before the new year, and in the display tank during Jan.
Cheers all!