It depends on what sanction is doing the testing NCAA, IOC, NFL???

I'm an NCAA athlete and have heard rumors and read accounts of people at about 100-200mg/test/week will keep you just at the 6:1 ratio... I have no actual proof of this from guys getting tested however. I personally would not take the risk.

The NCAA does not test for an Ester, simply TEST:EPITEST which your body produces at almost an equal amount. If your found to have over a 6:1 ratio, its a positive test.

The NFL is going to a "system, called CIR or carbon isotope radiation testing, can unequivocally detect the use of artificial testosterone. Due to costs and a lack of lab machines the league currently only uses CIR to confirm positive tests."
Due to costs, I don't think we have to worry about these expensive tests for testosterone or future HGH tests which the NCAA will not be able to budget.