I highly recommend NOT to use Pond Armor. The internet is plagued with this product with little or no information how to use or apply it. The coverage is also exaggerated, you should double or triple the quantity of the product should you still want to use this product.
I recommend you look into a product called Thoroseal with Acryl-60 which gives you a much higher coverage.
I myself was very disappointed with Pond Armor and ended up having to remove it which wasted a considerable amount of my time and resources, this stuff isn't easy to remove once applied, so unless you sure don't buy it.
What also surprised me is the lack of video's of people actually using the product. Even on Pond Armor's website, there is only a few video's which only show the larger pond and they basically rolling it on like paint which wasn't the case with me.