Has anyone used KELP. IF so, what did you think?

One of my boys is allergic to it

You have to be careful that your dog does not have thyroid issues.

I use it with the dogs I'm showing and breeding females. It is great for coats.
It also has lots of iodine, so it helps the thyroid work better resulting on improved thyroid function, and improved fertility.

It also helps darken pigment.

How does kelp affect thyroid issues?

If you suspect your dog has thyroid issues GO TO A VET! Get bloodwork done!

Meanwhile, if you give your dog kelp his pigment may improve or stay the same or get worse. If you do nothing his pigment may improve or stay the same or get worse. In the first case, you could also be improving the economy by giving money to the person selling the kelp. In the second case, you could be improving your own financial situation.