Hello Drwhem!
So there's quite a bit going on here. So much so that I'm going to try and keep this as short as possible. But first, can you please report your hardness (aka GH) and your karbonate hardness (aka KH) and please report those in the measure named degrees. So these numbers will look like: example, 4dGH or 4dKH. I ask you to convert these numbers because this will cause, maybe, a bit of research on your part.
You mention 1 cap Flourish a week. Do you add anything else?