During the 2001-2002 school year, we at Lakeview High School created a hydroponics unit to grow lettuce.  We did this along with six other schools  in the state of Nebraska. It was first made in the summer of 2001.  We made  many changes in it because of leaks and other problems in January of 2002.   Here are the steps we took to create it, the basic structure description of  our unit, some problems and solutions that we worked through, and the results  we have attained so far. We hooked it up to a wood frame.  It gets its water supply and  fertilizer (which is a standard miracle grow solution, that is one tablespoon  per gallon) from a garbage can that has three different hoses that run from  the tubes.  Valves control this and a pump in the garbage can controls the  flow. We have four light fixtures, which supply heat and light.  The plants  are kept at room temperature. We used three different variables for planting. The first variable is  made up of plastic cups that have vermiculite and the wicks, which are made  out of interphasing.   They have wicks that run all the way to the top from  holes in the bottom of the cup.  They are set in PVC pipe, and the water flow  for that tube is controlled by its own valve.  The lettuce seeds are then  planted on the top of vermiculite.  We have had major success with one of  these cups.  The other four are also doing very well.

The next variable is rock wool that is set in a plastic cup that has slits in  the side to let water inside.  The seeds are then planted inside the rock  wool. This also has its own PVC pipe and valve that controls water flow. These are all doing very well.  We took plants from our germination chamber   and transplanted the entire rock wool into our unit.  These are continuing to   grow successfully. The last variable is two pieces of rock wool wired together and placed in PVC  pipe with wicks running through the rock wool, and the seeds are again   planted in the rock wool.  These plants are not doing so well.  Some appear  to be burnt and not growing at all. The main problems that we experienced were troubles with flow level  in each pipe which led to one pipe getting too much water and another one,  not enough.  So there was uneven distribution of water and fertilizer to the  pipes.  We fixed our problem by putting separate valves on each pipe, which  is then controlled by the main valve.  Another difficulty that we had was  leaking.  We believe the best solution is just to use silicone caulk to patch any leaks.  The temperature also became a factor because the plants were being fried.  We now have it at room temperature, and a thermometer monitors  it. 

These were the main problems that we have come upon with our system.  We  have been able to solve all of these problems within reason. We have now also designed germination chambers to experiment with different  types of seeds.