Try adding some Flocculant(alum-> aluminum sulfate etc) and some Purigen.
That will remove it.

I just do water changes, never had this issue but have seen on line several folks that have.

Well cycled filters help, mulm from another tank will help and should be added to any new tank/substrate.

I think product variation/lack of consistency is a real issue, some batches are not so hot it would seem.

I've used some that works great, some that leeches a lot more tannins than the others, some that has more fines in it.

I think the product is not particularly consistent, but still good.


Regards,
Tom Barr