The project is: http://www.sciencebuddies.org/science-fair-projects/project_ideas/PlantBio_p045.shtml
We are two weeks into growth and our stems on the hydroponic sprouts are starting to turn brown and collapse. They are not dry, but seem to be withering or rotting. They are being grown under a grow lamp, and the soil group next to them are doing fine....water has been changed once. Any suggestions?
Additional information about their experiment so far:
Also, to confirm, you are using the grow lamp for both the hydroponic
plants and the soil plants, right? And the same amount of time for
we are using the 15W T-8 fluorescent grow lamp on a timer for 12hrs of light per day for soil and hydroponic
each. Lamp is placed about 15 inches above top of pots.
Both of your samples are using lettuce seeds from the same packet, correct?
we used the seeds from the kit for both
Also, following the directions in the project, you are aerating the
nutrient solution twice a day? (Step 6 of "Growing and Feeding
Instructions": make sure to aerate the nutrient solution in the
terrarium. A plant's roots need oxygen in order to grow. Follow the
instructions to learn how to use the manual hydro-pump to do this. You
should aerate the solution twice a day.)
Yes we are aerating twice/day
In addition, the nutrient
solution should be replaced each week -- and strengthened once the
roots appear: "Replace the nutrient solution in the hydroponics
terrarium every week. Once you can see the roots stick out from the
rock wool, strengthen the nutrient solution as directed in the
we have only changed the nutrient solution once after its initial fabrication.