Just got a bunch of sand and didn't realize how many rocks were in it till we spread it out... ugh!  Any suggestions other then picking up by hand on getting them all out? We got alot of big rocks out, but there are so many med and small rocks... 

Is there are rental place near you that carries a derocking attachment for a tractor or someone near you to hire with the attachment?  We have a tined rock/landscape rake that we use to drag the rocks to a pile so we can pick them up with a bucket attachment.  It does ok for the larger stones in some cases will catch the medium and smaller ones.  The derocking attachments are cool.  I use a manual road rake with the smaller tines for my  round pen.  I think the rocks grow.  My last dump of river sand was the worst ever.

I swear they grow too... especially once you drag it again walla surprise! More rocks... I am actually asking the rental places around what they have... we have alot of 2" or smaller... and some bigger... we have gotten a bunch of the bigger rocks... 2 tractor buckets full!  

Check in the Mahon Pro Footing on Facebook. It's not cheap but its worth it. My arena was a ton of gravel and he made it tremendously better.