Look into what you are feeding him. If he is not getting all his dietary requirements met, he will be unable to grow healthy, strong hooves. I would prefer feeding biotin over gelatin as gelatin is an animal by-product and horses aren't designed to process animal products. However, which ever way you go - It will be a long process as the new, healthy hoof growth has to grow out from the coronet. Depending on the rate at which your horse's hoof grows, this can take between 6-12 months.
Hoof grease will help keep the hooves from drying out and becoming brittle, so if you aren't already using it it may be something to look into. Balanced Equine Nutrition - Feeding for hoof health http://animalscience.ag.utk.edu/hors...ves-ASH139.pdf
What also helps to stimulate hoof growth is exposing the hoof to lots of different terrain. If a horse is on sand all the time, his hooves will never cope with being worked on harder or possibly rockier ground. Just like us, if we walk around on soft sand, grass, carpet and smooth surfaces all the time and are then made to walk on gravel or bitumen/asphalt... well we aren't going to be super comfortable. :)
Not sure if this helps (as I know Ontario is a huge place), but here are some barefoot trimmers in Ontario certified trimmers
Here is another list The Horse's Hoof: Professional Trimmers List
Maybe search on facebook in local pages for a good farrier near you? Ask friends who they use and see if they are taking new clients?
This may be interesting for you to read... I know it is in Australia but the work Andrew and Nikki do, rehabilitating hooves and teaching people is really cool. You might get a few ideas? Mayfield Barehoof Care Centre Home Page
They have some cool little things called barefoot tips... which just protect the sole of the hoof but still allow the hoof to work as it was designed to. They aren't as heavy or as big as normal shoes and seem to be a bit harder to pull off. They may be worth investigating. :) Good luck. Xx