Advice Needed-sludgy bubbly appearance on pond lining/rocks/pipes

[cdibden]

Been having this problem for a couple of years and wondered if anyone knew why or how to treat it?
We get a green, sludgy bubbly appearance on our pond lining, rocks, pipes and everywhere in our pond. The water remains clear but the sludge appears green/brown and will flake off in large clumps if disturbed.
We currently have no fish in the pond so if we need to treat it with chemicals we are able to.
We have a filter, UV light and real plants in our pond. We have a stream running into it and a water fountain that is on daily during the day.

Can anyone help with why this is happening and what we can do about it?

 

[j.w]

@cdibden
Looks like brown algae to me. Here is a link about it: https://www.velda.com/pond-maintenance/algae-removal/brown-algae/ Or do a search on your own for Brown Algae in a pond.

 

[Mmathis]

Hello and welcome! That is impressive!

 

[Jhn]

Could be Cyanobacteria or dinoflagellates. How much circulation/Turnover ( should be 1.5-2x pond volume per hour) do you have In the pond? Does your pond have an ionizer?

Cyano Similar to algae can be gotten rid of with better circulation, so any decaying matter can be removed by the filter. If it is cyano, without any fish in there to contribute nutrients to the pond you should be able to starve it out.

I ask about the pond ionizers because they are notorious for making the conditions right in the Pond for dinoflagellates to take over. If this is the case stop using the ionizer and toss it, then This is one of the few times I would drain and clean the pond.