Hydroponics

Hydroponics is the growth of plants in a liquid medium, rather than soil. Plants are often supported at the stalk, leaving the roots free floating. In other cases, roots may be supported by inorganic media, such as plastic pellets, gravel, or mineral wool. All nutrients are supplied through the liquid.

The liquid is held by vessels or pipes, that in some cases include a circulation system with automatic renewal and filtering. All parts that are in regular contact with the liquid are cleaned or replaced in regular intervals.

Advantages

This method provides several advantages to a colony on Mars:

Disease Control
Increased Crop Yield

nice choice for a hobby. you rellay should block light to the roots mabey pant the coke bottles (the bottom halve) black or wrap with tape. Or real good layer of black to absorb the light then a layer of white to reflect on outside. the hydro unit same thing. don't let the roots get light. i have a feeling your ph is off. i may be wrong (i didn't see any bottles of ph up and down) for hydro keep it at 5.8-6.5 and dirt 6.5-7. the algae is from light, place black plastic over it.peace