Can someone please explain when to use which ratio? I’m brand new and confused!

Okay so I’m just wondering when each ratio is beneficial. I’m not sure if this is standard format but mine below is starter:flour:water

1:1:1

1:1:0.75

1:2:2

I started out using 1:1:1 to establish my starter, then someone suggested using less water and doing a 1:1:0.75 ratio to increase rising (I think?). But I’ve been using that ratio now for a few days and although it did help initially, my starter seems to be struggling a bit now (not rising as much).

I’m wondering if it’s time to switch to a 1:2:2 ratio?

Thank you so much!