I hope you are very successful. I am one for slow growth, but if your back is against the wall you gotta do what you gotta do. I would just be careful that you build a safety net and don't spend all the spare money on equipment. Man a guy can blow so much money in so little time that at the end of the month there is nothing left to even get the gas you need to keep going. This is good advice, trying to work on this system to help him out will lose you time and money where as he needs to get a irrigation guy that knows his stuff. The best thing you can do for your customer is give him the same advice. I do some minor work on them like replacing heads or replace a solenoid, But anything bigger than that I would leave it to the Pros if your main business is mowing/lawn up-keep.