My 01 Subaru Impreza has blown head gasket be used a bottle of gasket repair their is no longer water in my oil but still blows white plumes mostly when it’s cold, radiator still bubble’s. Radiator has tiny crack in top which it blows pretty much all the water out in a short period of time??? I have taken thermostat out.

What do I do

Wow - It is not the way I would have approached the repair. You will get some white vapour until the engine is warm that is normal. I would replace the thermostat and get a new radiator.