Now for the modifications
Individual waterfarms.
The first thing that you want to do is to drill out the holes in the upper chamber. They are too small and do not allow thr roots to get into the lower chamber. I drill them out to be slightly smaller than the hydroton (or whatever your using). This prevents the hydroton from falling into the lower chamber. This also allows the root system to get into the lower chamber.
By adding an air stone to each waterfarm, they can become a DWC system when the roots get into the lower chamber. This combination of a drip system and DWC system provide lots of oxygen and nutrient to our babies. I normally use the drip system when they are little and switch to DWC when they get bigger.
8-pack system
One inherent problem with the 8-pack system is keeping the nutrients in each individual unit to the correct PH and PPM. You would have to check each unit, and both reservoirs.
General Hydroponics realized this and created a circulation system kit. This system circulates the nutrient through all of the individual units and back into the lower reservoir chamber. The kit costs about $30, but can be created by purchasing the individual parts for much cheaper. The system uses the same percolation tube to circulate the nutrient as the individual waterfarms use to pull the nutrients into the drip ring. You can purchase the additional grommets, tubing and a waterfarm modular kit (that has the percolation tube) and do it yourself.
Here is a picture of the General Hydroponic installation instructions for the circulation kit.
The link for this pdf is located at the end of this tutorial.
As you can see, the circulation kit is pretty simple to replicate for the DIYer. If you don't want to DIY, you can purchase this upgrade from any Hydro store, they may have to order it in.
Now you have a system that will circulate the nutrients between each unit and the lower reservoir. I know of some growers that just use the lower reservoir at this point.
I wanted to incorporate the upper reservoir into the system, but ran into a problem with the upper reservoir not having the same PH and PPM as the lower. So I needed to include the upper reservoir in the circulation system. To achieve this, I installed a small submersible pump in the lower reservoir that pumps into the upper reservoir. As the level in the lower reservoir goes down, the float valve opens and the contents of the upper reservoir drains into the lower reservoir. I placed the pump on a timer and it runs for two minutes every hour. You have to make sure that the pump doesn't work faster that the ability to drain from the upper reservoir into the lower.
Now I have achieved a system that incorporates all components of the Waterfarm system and circulates the nutrients between all reservoirs.
With an air stone in each individual unit, I have created a drip/DWC system with a large reservoir capacity that circulates the nutrients through all components of the system.
A couple of things to remember:
Use dark tubing to prevent light from getting into your system. Light = algae.
Kee your nutrient temperature below 75 degrees to prevent algae.
Make sure that the lower reservoir pump doesn't work faster that the gravity drain, otherwise the pump could run dry. This is why I only run my pump for a couple fo minutes each hour.
