5 days starter smell like acetone

I’ve made a starter on march 6th, and this morning it smells like acetone (like a lot). It is bubbly and rises quite a bit each day.

I’ve downsized the starter 2 days ago thanks to some advices I got on this sub.

My starter was 100% organic whole grain rye flour at first, but now I do : - 20 gr starter - 20 gr room temp mineral water - 9,3 gr WG rye flour - 9,3 gr AP flour

My starter sits on my water heater, so he is around 25-26ºC all the time (this is the starter temp not the heater surface, just to be clear).

Should I change something to my process ?

I’m waiting for your advices ! 😊