Have lived here 6 yrs no security deposit required you own your mobile home now new owners of park want to charge a security deposit can they do that?

It would depend on what your lease says. Typically the new owner would have to honor the lease. However, when the lease is up then the landlord could do whatever he/she wanted to renew. You are within your rights to ask the landlord to show where in the lease it says a deposit can be charged. If you have no lease, you are screwed and you'll have to come up with deposit. In all cases try to negotiate. Landlord wants deposit incase you bolt one night or somehow damage his property. If you have to pay offer a lower amount, ask for a lower monthly rent, always agree to pay a month in advance or find a new home site.