Got a client that had a landscaper do hydroseeding job for him last year. The seed didn't come up in alot of places so the are is very patchy. He wants to put more seed down. He wants us to rake it all first then lay the seed. I have never done a job of this size. What equipment could I use that isn't going to ruin existing grass. I really don't want to have to hand rake a 5000 sq ft area!! Your advice please!