I don't like the tenor of some of this. Next step is posts deleted which will mean info disappears.

Fish change color for lots of reasons. Search for fish coloration. A lot more than just water color/clarity.

Bacteria can help in some cases but IMO it is limited and expensive.

We don't need or want non Pond Boss advertisers posting about sales here. Talk to Bob first then know there are a lot of very critical eyes on here so bad advice will be challenged and corrected.