Perhaps you don’t have a lot of room in your house, but you would like to try growing something, using the simplest method possible. Then this post is directed at you. Here is my plan:
I will be growing Red Sails lettuce, a fast-growing variety which has always done well for me in the past.
- Plant will grow in a 1/2-gallon glass canning jar, and I will cut a 2-inch hole in the plastic lid to hold the net-pot. I will need to monitor the fluid level to make sure it doesn’t run dry, and add more fluid as needed.
- I will use the simplest fertilizer blend that I have: Dyna-Gro’s Liquid Grow, a 1-part liquid fertilizer concentrate.
- The plant will grow beneath a fluorescent light bulb under my kitchen cabinet. My bulb is a 2-foot T8 Daylight (6500K) bulb.
Jan 7, 2016 = Day 0. Plants started from seed (Botanical Interests). Seeds sowed in 1.5-inch rockwool cube in 2-inch net-pot. Moistened with dilute fertilizer solution: 1 mL (1/5 tsp) Dyna-Gro Liquid Grow, 1 mL pH Down per gallon of tap water. Nutrient concentrations (in ppm): N 18, P 24, K 13, Ca 5, Mg 1, S 0.13, Fe 0.26, Mn 0.13, B 0.05, Zn 0.13, Cu 0.13, Mo 0.002, Ni 0.0003, Co 0.004. pH = 6.0.
Jan 11, 2016 = Day 4. Plant germinated, placed directly under a fluorescent light (2 ft. T8 bulb, 17W, 6500k) for 16 hours per day.

Jan 20, 2016 = Day 13. Installed plant into 0.5-gallon glass jar (8 cups). Hydroponic solution composed of 0.5 gal tap water, 3 mL Dyna-Gro Liquid Grow. Nutrient concentrations (in ppm): N 111, P 143, K 79, Ca 32, Mg 8, S 0.8, Fe 1.6, Mn 0.8, B 0.3, Zn 0.8, Cu 0.8, Mo 0.01, Ni 0.002, Co 0.024. pH = 6.0. No pH adjustment required. The glass jar was wrapped in foil to keep light out, which prevents algae growth.

Feb 1 = Day 24. Thinned to just one plant in net-pot.

Feb 14 = Day 38. Plant has used almost half of the hydroponic fluid in the container. Just over 4 cups of fluid remains. Leaves can now be harvested at any time.

Feb 24 = Day 48. Plant has used 75% (6 cups) of the original hydroponic fluid, only has 2 cups remaining.

Mar 1 = Day 54. Harvested all leaves. Final statistics: 6 cups (0.375 gallons) of fluid used. Final pH of fluid < 4.0.

The final pH of this Liquid Grow-based hydroponic solution was very low (pH < 4.0) which is consistent with what was observed when I grew Marvel of Four Seasons lettuce in this post. The root system looked better when I used the Masterblend fertilizer, so I will probably switch back to using that for my hydroponic solutions, even in small-scale (< 1 gallon) applications.
In conclusion, I have shown how easy it is to grow a fine looking and tasty head of lettuce, using a very simple hydroponic set-up consisting of a small 0.5-gallon container, the Liquid Grow all-in-one fertilizer, and a standard fluorescent light bulb on my kitchen counter. Give it a try!