Yah, that's not a problem, I do it all the time, and my plants thrive. Just don't water anything that produces fruit or veggies that you intend to eat.
The only reason not to use tank water on veggies is if you are using medications or other toxins. Other than that, if you wash the veggies before eating, you're fine.
Don't put water from saltwater tanks on the garden, though!