ton cano

i have been trying to find this answer, would seem like others have had this situation but I can't find a thing. if you have a 401k plan with safe harbor and no employees want to participate do you have to pay the 3% or can you say you are doing the 4% and since no one is deferring, there is nothing to contribute ??? and if you had just one NHCE, you could do 4% for them and you would satisfy the requirements? I hope this makes sense thank you so much!!