Good day eh!
My name is Jim, and I need some help. I am a level 2 ice tech in Ontario Canada in a 3 sheet club in a small town. I am proud of the ice I make for our members and guests. Speed is good with a good draw behind tight guards and you can go get em with a good shot. However, at bonspiels where the curling goes on all day Saturday (6 draws) without a chance to scrape or shave the ice, we loose speed. We mop and pebble and nip between games and the IST is adjusted lower to help keep pebble through the games as the day goes on. I have experimented with different pebble temps to try to solve this problem, but have come up with nothing conclusive. If anyone has some more suggestions I am all ears. Thanks for listening.

Thanks Phantom
I did make an incorrect statement in that I said I lower the IST through the day. Not so, I lower the brine temp to try to maintain IST.  Our plant isn't overly strong so I have to keep an eye on temperatures as the heat builds up through the day.  I will certainly try smaller holes. I am helping with the ice at the Quebec senior mens and ladies this week and have had a discussion with the head ice maker regarding this. His suggestion was the same as yours Phantom. Sounds logical when you think about it.
Cheers