If you are trying to only gain 10lbs and that being lean, then the diet is going to be atleast 80%, with cardio being the rest. Heck you could do what you are wanting by sticking to a great, clean diet without the gear.
Also, a test/deca cycle is going to bloat you some even on good diet. Drop the deca and change the test c to test prop(less bloat for most). Keep the diet up for now and see what happens. Gear is the icing, not the batter.