No filter - what to do?

Hello everyone :happy:
Been a while since I last posted on here - always a treat to pop back & check out all the cool photo's & good advice!

My filter recently stopped working, and as a result I've been without any filtration for a couple of months now. Although initially the water quality worsened somewhat, it seems to have 'levelled out' & if anything both Colin (my Axie) & the tank seem to be in better shape...
These are only casual observations - his gills seem more 'fluffy' and he's a bit more active. The water smells good to (very scientific! lol) by which I mean I've noticed it smells far less pond-like & sharp... if that makes any sense at all? I'm wondering if I failed to clean out my old filters sponge frequently enough in the past & this had a negative impact on the water quality. I do check the chemistry with a dip-test (think it's Tetra or something) - not the most thorough way I know - but I try to keep an eye on that to make sure Colin doesn't suffer.

I'm cleaning his tank out with an aqua-vac once every 2 weeks & and removing a couple of lunchbox-sized pales of water, & adding clean (dechlorinated).
What are other peoples thoughts on a tank without a filter? And how often should I be changing water/cleaning?

P.S. I've added an air stone, which I have on a couple of hours every day to help the water circulate.

Beneficial bacteria grows on the substrate, and whatever else is in the tank, so while a filter does keep the tank looking cleaner as long as you keep up with the water changes I don't see a problem with keeping a tank filterless. The airstone is a good idea, becuase you don't want stagnant water.

I don't use a filter in my axolotl tank either, unless you count the sponge filter. I think my axolotl seems healthier without it.

I only have one axolotl in a 30 gallon tank, I do water changes every 2 weeks. I take out 5 gallons of water, and then add enough to top it back up (accounting for evaporation).

It is possible to maintain an axolotl without a filter. The airstone has more benefit than just to circulate the water. It also helps keep the oxygen level up, which is good both for the axolotl and for the beneficial bacteria that are doing the filtration. You might want to run it all the time, or as much as you can.

The amount of water that you are changing out sounds rather small. Have you tested the nitrate? It could be creeping upward.

Thanks for the replies

Good to know that others maintain a healthy tank set-up without a filter to!
I will keep an eye on nitrate levels & start changing a greater volume of water - thanks for the tips.