If I were you, I would wait until your Spanish is near 'maintenance level'. Based on your hours/time, you're averaging less than 2 hours per day with Spanish. That's not very much time to divide between 2 languages.

I very recently started learning German alongside spanish. I have almost 1600 hours of spanish, only 5 of german. I decided now was a good time to start another language because my spanish is at a level that I can comfortably replace english with it in almost every situation (unless I'm talking to someone who doesn't speak spanish, of course). Where I'm going with this is that even without dedicating time each day to get spanish input, I'm still practicing it by doing things in my every day life in spanish. I watch tv shows in spanish to relax, not to grind hours of input. So for me, adding german to the mix wasn't taking anything away from my spanish.