Is it a pull behind aerator?

No it's a walk behind(self propelled)

One pass will pull up plenty of dirt, so I'll be surprised if you need a 2nd pass in the other direction. No way you'll get more than 2 passes done before your wife & neighbors physically remove the aerator from your possession, it'll be a mud fest by then

Lol im confused, what are you saying? Are you saying neighbors will want to borrow it? And it makes a mess if more than one pass?

I've done a double pass before....plugs everywhere, made walking barefoot through the turf unbearable for weeks.

I had the guy who aerated mine do about 4 passes using the walk behind plugger. It was perfect for overseeding into. Note - I prepped first by scalping and dethatching.

What Zeus said. 2 passes is more than enough unless you're seeding into it. I think a pro can do 4 or 5 passes but I wouldn't try that

the home depot rental unit does 9 cores / sq ft. How is that enough?

A minimum of 20 plugs per sq foot is commonly recommended by turf specialists (some suggest 10% of the lawn should be cored). 3/4" tine (pie are squared, carry the 6... ) each hole would be .44 sq inches in area. 20 holes would be 8.8 square inches per sq foot. one square foot is 144 sq inches. 8.8 divided by 144 is .06. So 20 holes per square foot would result in coring 6% of the lawn. Anything much over three passes and you might as well roto-till based on the resultant damage and mess. :/

I don't think we know what kind of machine he's renting or where he's getting it, but some of the nicer rental units are adjustable for depth & core frequency. If he gets one of those, one pass could be equal to 3 or 4 passes from the home depot unit

My point is you can't say how many passes it takes without knowing what machine you are using. J4c11 mentioned tow behind...most of the cheaper ones you really need 6 passes or more. In my neighborhood, the landscapers I'm sure do one pass and don't do enough cores. That's one reason to rent the machine yourself and do as many passes as you want. Especially true if overseeding and want more cores.

Thanks guys. The machine I rented I think was old fashioned. It worked but very hard to maneuver making turns. Also my lawn was really wet in some spots. There was a 100sqft area that was completetly saturated ti the point the wheels made ruts all over and my feet were sinking in. I kept at it like an idiot. So now that area looks like bicycle tracks. Anyone have any ideas how to fix it? I don't think I would do it again unless it was a really decent machine and maybe when lawn is dry.

You could fill the ruts with some top soil.