Hey guys, I've been struggling with some adjustment I need to make in my game depending on the structure of the MTT.

I usually keep my strategy of playing pretty tight on early stages, where there are no antes and the blinds are low, try to accumulate some chips and as long as the blinds increase and especially when the antes come into play, I start to open my range and aggression, stealing more blinds, make some moves and stuff. 

It works pretty well on most MTTs, where the antes come into play on  40/80 or 50/100 levels, with 3k starting stack when start the antes most of the players have a decent stack, so I have enough room to play and make moves. 

Yet there are some regular MTTs where the antes start on 125/250 level, with 3k starting stack I cant wait for it to start opening my game, because on that level even if I had doubled up once  I will have around 25BB stack and not so much room to work. Thats where Im struggling, I cant find the right timing to start aggression pre antes on those tournaments and constantly find myself on that spot with ~20BB when antes come to play and I have no room to play my best game.

I would like to know what adjustments you guys think I should do, when and which level should be better to start to open my ranges and aggression on these tournaments?