first off i think you mean your taking 500MGS And 300MGS of each. not ML. that would be a bit much lol... second, alot of guys will tell you for a first cycle test is all you need, which is true. sounds like you got the stuff and your going to do it anyways.. so heres my advice. yes keep the deca dosage less then the test dosage. also make sure you have enough test. you said your already third week in and adding the deca. deca should almost always be ran 10-12 weeks atleast and you need to run the test a week or two longer then the deca..