Conclusions

Is HydroBok better than commercially available hydroponics with specialized nutrients?

This is still too soon to see, but leaf color in the spinach is worrying.

Do we recommend?

Separately? Yes! Hydroponic is a fast and clean way to grow food at home. And bokashi is really good for potted plants and as a soil factory. But the combination of the two, too soon to say.

Is it easy and cheap?

There is an initial cost for procuring the equipent needed. For the hydroponic system, the most expensive items are the container and the air pump. A growth light, if needed, can also be costly. In Norway the Trondheim municipality offers funding to facilitate acquisition of bokashi bucket.  Maintenance cost is reduced afterwards.

The system is easy to set up, provided that you have the right equipment.

Is it sustainable?

From the food waste point of view, bokashi composting results in less waste being processed the municipality. 

Regarding water consumption, hydroponics system usually consume less water then plants on soil, because drainage and the evaporation are reduced. However, during the first two weeks of this experiment we needed to change the water from a 40L container one time. 40L per week is much more than potted plants would need. So right now the system is spending too much water. To reduce is one could have different sizes of containers. That is because young plant don't really need a 40L container. 

Growth light - these are LED base, so consumption is very low. Small growth light for domestic use vary between 7 and 20W. And obsviously, they are not a mandatory item. But if you need a growth light for a hydroponic system, it is very likely that you will need for potted plants as well.

 

Air pump - these are also very low consuming, around 5W.

Future study

Our project only lasted one semester, but there are a lot of unresolved issues that could be looked into. Here are a few:

• Run the experiment for longer time;
• Test other crops;
• Start with seedlings - we made the bad decision of startings with straberry seeds, and they take, as we later learned so, extremely long time to germinate.
• Test prototype with bokashi tea made with different food waste;
• Get chemical analysis of the bokashi tea being used - there is not a lot of academic references about bokashi nutrition;
• Test comparatively with other hydroponic solutions.
• Run the same experiement with same crops but varying number of hours that the airpump is running on a daily basis. As the bokashi tea has both aerobic and anaerobic bacteria, it could be that too much water oxigenation will do more harm than good, alowing aerobic bacteria to grow.