Hi, and welcome to the forum!!

First of all, how are you measuring test levels? Because a pool with zero chlorine is a pool full of bacteria, viruses, and probably algae, whether it contains ammonia or not. Second, the source of your ammonia, if you have it, could be any of the products that you're putting in the pool (many algaecides are ammonia-based). If you could list the ingredients of those Bioguard products, that would help us determine if any of them are ammonia-based. Have you had the water tested for ammonia specifically?

The webby material that you describe sounds like water mold and is a common complaint with people who use Bacquacil. It can form in chlorine pools, too, if the chlorine levels aren't kept high enough.