Hi, make sure that you don't replace Deca with your Test. Test is HRT, Deca doesn't do anything for your testosteron level, so you can't replace it. Just add Deca to your test dose. Start with 100mg per week, and increase up to your feelings. If 100mg/w will work, stay on it. Every time stay on the smallest amount which you need, especially on HRT. Also, check your E2 a Prolactin, after 3 weeks from your addition of Deca, to make sure if Blood work is ok and if you have to adjust your AI's or add Prolactin inhib.
I wish you painless joints