object pooling on mobile

hi im using object pooling for a mobile space shooter and everything works fine.
but when i start shooting those deactive objects and activate them, it stutters on my mobile device. i noticed this in earlier projects and i worked around it by just deactivate the graphics and not the collider but maybe some of you know a better way to not leaving the collider in scene. im certain its about the garbage collector which clears the deactive colliders.

Yes my game is 2D i have like 70 objects pooled, which can extend if needed but i dont use any physics in my game, i used rigidbody for enemys and box collider on those as for bulletfire sprites, all set up as trigger.

Since i dont use any physics i wrote my own little collision detection and removed any collider and rigidbodys which works fine for me now.