start up a vegetable hydroponic
I would like to startup a vegetable (mainly lettuces) garden in my back yard in downtown Baltimore. How and where can I get a local expert assistance?
Do you truly mean hydroponic, as in growing in water without soil? We don't have a lot of information about that. You could go over to Cylburn Arboretum in the city and look at their set up with aquaponics, where they are raising fish too.
If you mean growing vegetables, we have lots of information for you, and Extension Master Gardeners can help you with your questions at their "Ask a Master Gardener clinics. A listing of where those will be held is here: http://extension.umd.edu/mg/ask-mg#city
Here is our 'Getting Started" page on backyard vegetable gardening: http://extension.umd.edu/growit/basics It also includes a link to another interesting way to grow lettuces-with a salad table or box.
Good luck! Remember that we are here season long to answer you questions for you.