[AirstoND]

1) If I made a mixture of both will it be stable for fertilizing a densely planted tank?

2) Has anyone done this with positive results?

 

[OverStocked]

Miracle Grow is not suitable for your planted tank. Particularly with livestock. It isn't about "stability". The levels and compounds are all wrong.

Lots of cheap options out there for fertilizing, so I'd use something a little more appropriate. If people could use miracle grow, it'd be done to death by now.

 

[jasonpatterson]

Dry fertilizers are the way to go for cheap, easy feeding. A year or two worth of fertilizers can be had from a number of vendors on here (GLA, for instance) for less than $20 shipped.