Algae Problems - looking for some help

[MitchM]

I'm wondering if it's a cyano problem, not algae, then.
Excess phosphates feeding your macros may be the explanation there, plus dying snails, maybe some ph swings at night, etc.
I'm in Calgary, so I don't know about your local water.
If your temp swings were extreme, that certainly won't help things.
Have you tested your source water for ammonia?

Mitch