Question on Potentially Contaminated Water Supply and Solutions

[FirBarkandBlooms]

Good evening,

Apologies in advance if I don’t follow the proper protocols for posting I am pretty new here.

I am currently using a small RO water system purchased from First Rays (which is great, not the problem here) which fills a 30 gallon plastic barre. I fill my watering cans from this barrel. I’ve become increasingly suspicious that the water in the barrel is contaminated with algae/fungus/bacteria that I am spreading to my plants because all at once many started exhibiting spotting and the only thing they all share is the water that comes from that barrel.

I am currently disinfecting the barrel.

My questions are:

1. Is the RO system contaminated too? The clean end was dipped inside the barrel as it filled. How would I sanitize it?

2. Is there something I should be adding to my water to ensure it is free from these bad things? Or is regular disinfecting the best solution.

Thanks in advance,