What size of super dos is the one for my yard?

There are a couple of factors that go into sizing a unit. We need to know what the flow rate is. Also, we would need to know what you are applying and at what rate your mixed solution would then be injected into the water. You would need to contact the company supplying the product to have them help you determine how to mix the solution and determine at what rate it needs to be injected into the water. Once you have that please contact our sales department to determine the correct size of you.