Thanks Mark for the clarification. I’ll do my best to explain the some of the queries you have.
I am still designing the system myself, so none of it is actually working yet. The system I designed above is an example of the system that is set up at another farm. To be completely honest with you, I’m just trying to design a system that works, and is simple to work out and build. The reason I’m posting here, is so that I can determine if Open sprinkler is capable of doing what I need it to do.
The second pump is not exactly needed, like I said I am just copying the system I examined. There was another one I saw that used 3 pumps in a slightly different set up. I don’t think those would be a problem anyway because in every system I saw all of those pumps turn on at the same time just like you guessed.
Concerning the technical specifications of the EC sensor, I am unsure exactly what they are, but I am confident that they can be mapped. The EC senses Electrical Conductivity, and is generally used to measure how much food is in the water. For farming, the values should be at around about 2-4 depending on the weather.
Whether or not I need the valves to open at a range depends on if it’s possible to manipulate the amount of liquid going through the valves in other ways. In my mind, I was thinking of using on/off valves, and then adjusting the amount of time they would be open (say 3 second intervals) to control the amount injected into the mainline. It could probably be done with adjustable valves but I think that is driving complexity higher.
To me it seems like it’s very complicated and that there is more going on, but as I’ve been researching it, it seems to be quite simple. Standard systems sell for upwards of 7k depending on how much of the system you want to automate. I’m looking for something I can build myself, so I know how to fix it if anything goes wrong, and won’t be to expensive either.
The only other thing I noticed from the other systems I examined was having a percentage based balance system for A&B. I thought it would be a bit of trouble to get it working on top of everything else but I don’t think it’s too important. Basically controlling a ratio A:B to inject into the mainline.
Like you say, keeping it simple is what I’m aiming for, and it’s looking like opensprinkler fits the job quite nicely.