Experiment with my 7 year old – Aquaponics aquarium with fish!
So my son and I decided that over this spring break we were going to start an experiment. In school they were learning about plants and how they grow and what they need to grow. I’ve been fascinated with the live gourmet lettuce. So one search led to another which led to another and bam I was reading about using our old 20gal aquarium as an option for growing food. I was thinking about using it as a terrarium and was tossing around ideas and then this hit me. The basic idea is from a couple of websites and based of what I’ve seen on youtube and various other things. I’ve gleaned the information that I needed and came up with a plan. So we went to the store and got some seeds and are going to start them all out from seedlings. If this works out well I’m considering a bigger plan/structure maybe consisting of a larger body of water with larger fish and a greenhouse? Who knows, but I think I can convince my mom and sisters to help with it too.
If you already have an aquarium, air pump, air line and air stone, all you need to add are:
- a small sheet of Styrofoam 1 to 1½ inches thick,
- Several small 3 oz. plastic cups,
- Grow media,
- Hydroponic nutrient, and
- pH test kit
Floating Platform – Cut the Styrofoam sheet in a rectangle with the measurements 1 inch less than the inside measurement of the aquarium for both the length and width. This allows for a ½ inch gap between the platform and the side of the aquarium around the entire perimeter. It is needed so the platform will float freely and not bind with the sides of the aquarium.
Drill or cut holes in the platform using the actual diameter of the plastic cup you are using. The size of each hole should be just large enough to let the bottom of the cup protrude through the hole to about ½ inch below the level of the water (bottom of the platform). Don’t make the holes too large, which would let the cups fall through. Space the holes according the crop you are growing. About 5 to 6 inches on center should be enough for ordinary leaf lettuce.
Drill or cut several holes in the bottom of each cup for roots to grow through. They should be about 1/8 to ¼ inch each.
Grow Media – A rockwool cube or similar grow block works great. Or mix ½ perlite and ½ vermiculite and fill each cup with the grow block or mixture. If needed to prevent the mixture from falling through the holes, place a small piece of cloth or plastic screen in the bottom of each cup.
Plants – Plant either seedlings or seeds in each cup. For seeds you should sprinkle water from above on each cup periodically until seeds have germinated and roots are forming
Nutrient Solution –Fill the aquarium with water. Mix the nutrient according to the label and adjust the pH. NOTE: When the level of the nutrient solution falls, add diluted nutrient as needed. The concentration of nutrient should be reduced to about ½ or ¾ strength each time to allow for nutrient concentration buildup due to evaporation. During especially hot weather, you may want to add water only or, if you can siphon it out you may want to mix a new nutrient solution for the entire reservoir. —Instead of this we are going the fish route and are going to use goldfish as they are hearty and really inexpensive. (about $.10 each)
Sunlight – If direct sunlight is allowed to penetrate through the glass of the aquarium, algae will form and cause a mess. To prevent this from happening, cover or at least shade the aquarium with black opaque plastic film or a similar material. Any method to keep direct light from entering is sufficient.
Finish – Add your platform to the nutrient solution floating on top, set up your air pump, line and air stone in the bottom of the aquarium. See illustration. Good luck.
So far, today we’ve started germinating the seeds. We couldn’t find the rockwool cubes or the other stuff, so we got some peat tablets (Jiffy makes them) Here is Day 1 of our seedlings started on 03/7/13