Hi Tony, Me again from Florida.
Jimbo is right. A sprinkler system is never a once and done, set-it-and-forget-it thing. Still, it is a very good thing to have, adding to the value of your property. While I am a licensed irrigation contractor, I have also been a Service Manager at a large full service Marina, and if you know boats, they are the same way. Very nice, as long as you take care of them. (Yes, there are many differences, but you know what I'm saying.)
As for your rust issue: Definitely have the water tested, because the amount of iron in the well water is key to resolving it. One very simple way to reduce staining is to make sure your sprinkler heads are properly adjusted so as to water the grass only and not your walkways and home, and to set your timer to water before dawn when the wind is very calm. I'm not familiar with the RidORust System of which you speak. Perhaps you could clarify? There are a few options out there and many come under different trade names. If the Iron content is light, it will still cause staining, just over a longer time span. If such is the case, perhaps it would be more cost effective to simply buy a rust stain remover by the gallon from your local Depot type store and apply it with a pump type sprayer every few months.
If the Iron content is higher, or you don't want to bother with that, consider a chemical injection system such as the one I'm familiar with that goes by the name of "Sprinkle Clear." It injects a solution via chemical feed pump directly to the irrigation water before it reaches any sprinkler heads and prevents the iron from coming out of solution. While not perfect, and stains will still appear where water can puddle and not evaporate quickly, it is effective. But it is costly and you do have to purchase the solution every few months, and it runs about $75 for five gallons, so is not cheap either. The solution is, if I recall, a phosphate based chemical that is not harmful to the environment, you or your pets, and actually has a benefit of reducing the surface tension of the water, making it 'wetter' so it soaks into the soil more effectively so you can reduce watering time by about 20%. You are the one who has to determine the cost/benefit ratio. I'm sure you can get information and pricing at an irrigation supply warehouse.
Just my two cents worth!