I agree with the above, a once per week 50% water change for adult fish like oscars in that size tank is a bit wimpy, and the buildup of nitrate with that lax schedule often leads to maladies like hole in the head scarring.
If that's all you can manage, it would probably be better to keep smaller less waste producing fish.
Anytime you have large fish like oscars, chocolate, or other cichlids the maintenance schedule that is adequate when young, often doubles as the size of the fish doubles in size, then triples etc etc.
Beside Pothos and Monstera, I use Dieffenbachia, and Umbrella palm (Aka Papyrus)
View attachment 1445561
View attachment 1445562
Papayrus below
View attachment 1445563
I had never heard of people doing more than 50% water changes at once. I thought it might stress the fish out too much, but if I can get away with doing a bigger water change once a week, that works for me. I have the aqueon water changer that attaches to the sink so like you said, it will only be a difference of minutes. I'll have to look into the dieffenbachia and umbrella palm more! Your tanks look gorgeous. I want diversity in the plants, so thank you for the suggestions. As for fish I'm thinking of going with 1 striped Raphael catfish, 1 sailfin pleco, 1 tiger oscar, and 5 spotted silver dollars.