Plastic water containers may not be a good idea for storing water.

[mark]

Didn't read the whole article in the link but did they test the water for contaminants (the containers actually leaching)?

As for IO, I had cyano when I started, but I'm still using IO and haven't had any for years. The outbreak I attribute more to just being a SW newbie; using tap water, over feeding, circulation just a few MJ1200 in a 75g, than the salt mix.