For the purpose of estrogenic side effect protection during anabolic steroid use, 10-20mg per day is common. If 20mg per day does not protect you from gynecomastia you will need an AI. If you cannot control water retention with this dose you may also need to consider an AI, but with a sound diet that is not overabundant in calories, especially carbohydrates, water retention should be controlled. Many performance athletes often inaccurately blame the steroids for their tremendous water retention, when in truth a lot of the time they’re eating more than they need. Overeating will cause you to hold water, add in aromatizing steroids and this will be worse. Control your diet and control estrogen through SERM’s and most should be fine. If an AI is needed and in heavy cycles and contest cycles they normally are, controlling cholesterol will become even more important.