Done 3 tca peels at 20% but still i have acne scars how many will i need to do before the scars go?

How many peels?: It is difficult to say how many 'peels' would be needed. It depends on the depth, you may require deeper. If the peel is deep enough you should see improvement. It depends on how extensive the scarring is as well. I use a laser to resurface the skin and vary the depth of the peel as needed. I 'peel' the skin until the scars appear smooth. Even then multiple treatments may be required.