I don't know how big your tank is Stephan, but a 25% water change for me is about 40l. So in 10l buckets that's 4 out, 4 in. And takes a bit longer than half an hour. Problem is that I can't start it unless I know I'm going to be able to finish, as taking time to wash my hands is usually long enough for all help to break loose! Cleaning the filter is one of the more time consuming jobs. There was actually mud in there last time!
I've stopped injecting CO2 and no longer turn on the extra led lights, so the plants don't grow so quickly any more. The down side is that I've got more of an algae issue, but it can mostly be easily removed. I have enough bottom feeders to stir up the gravel just enough that I don't seem to get a noticeable build up of milk. And the tank ispretty heavily planted - even more so as the cryptocorynes have taken over with the lack of 'gardening'! Last time I changed the light tubes, I put in one with a lot more yellow / green in the spectrum. I will be using those for both tubes going forward as the extra light means that my limnophilia has gone beautifully bushy, and stopped getting leggy so quickly.
I also don't feed the fish as much as I used to. Before they got 2 meals a day. Now they get one meal most (but not every) days. I will get to a point where I find the ideal routine, but I'm not there yet as it's difficult to establish a routine that specific with my little monster. Other reason for not doing anything fish related is that monster is just started to learn how to open cupboards and I don't want her to realise that there are cupboards under the fish tank. I know it won't work forever, but I want to put off having to child proof the fish tank as long as possible. Not sure how to do that with push catches.