Simultaneous time control

Hi friends. I'm finishing at school the chess lessons and I'm doing a presentation to the parents. I've already organized a swiss tournament and was a success. Now I have plans to make a simultaneous. Last year it was by myself. I have 1900 elo and all my students were beginners, so it was very easy and I think it wasn't so challenging for my younger students. This year I have another plan: one of my older students (1300 elo) will make the simultaneous: my younger students will have a chance. Since there will be no more than 12 boards, I think it's a good idea to use clocks. So, here is my question:

What's a good time for 10-12 board simultaneous exhibition? The exhibition will last about two hours.

Thank you,

Gustavo Olivares

ZegarraChile wrote:

Clocks are not usually used. The rule is that when the master comes around to you, you have to move, immediately, or pass. Usually the number of passes allowed is small, like three. If you don't move, you lose.

/  Do you even own 10-12 clocks?

Yes I have it. And we can improvise with the phones, since chess.com has a nice app of a chess clock. I think that 12 boards gives too few time to the player.

Masters and Grandmasters can move a lot more quickly than 1300 rated players. Your 1300 may have quite a challenge to keep ahead of the beginners, who can also throw out random moves quickly.