Water (bad water) is usually the carrier for protozoa parasites such as giardia, cryptosporidium etc. Generally water is not the carrier for worms. Humaworm or any other formula similar will not have much of an effect on these parasites, those products are geared toward nematodes/flukes.
Neem is a better choice when dealing with protozoa bugs but may not be enough to conquer them.
The parasite you describe as being like angel hair pasta is probably toxocara, there have been a few reports on this forum about these. Since you have had success with neem, I hope you would not stop it. I used Neem along with boswellia, enteric coated Oil of Oregano (by NOW), and myrrh (Nature's Way) and expelled roundworms.
The only proper way to treat is to identify the culprits and treat accordingly. The only test to use is Metametrix GI Effects Stool test.