White residue on surface. (1 Viewer)

[R33FM4N]

There is a white film on surface of the sump. It has a slimy consistancy. I tested water parameters (ammonia, nitrates, nitrites, calcium, PH, hardness, phosphates) and the only thing that seems to be off is that the phosphates may be a little high.

Any thoughts on what it could be?

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[TX_Punisher]

Do you dose Kalk?

 

[gregg]

Salt creep?

 

[DwPolcyn]

I had something similar on my 24gal where there wasn't much water turnover on the surface. I would guess it's some form of algae.

 

[steveb]

Salt creep?

that or maybe calcium deposits

 

[R33FM4N]

First off, thanks for the responses.

To answer your questions/comments, I do not dose the tank with anything, and I am positive it is not salt creep or hard water deposits. it is not hard or granular. It may be an algae, but I have never heard of or seen a white algae, other than white hair algae in freshwater tanks. Maybe a bacteria???

I have not replaced my membrane filter in my RO system for over a year. I thought it may be related to that. I replaced it last week, so I guess I will know shortly if that was the culprit. I also bought a TDS tester to see what that turns up.

It is funny that even after 4 years in the hobby, I still run into things I have never seen before. I guess that comes with the biological diversity that SW tank bring to the table. LOL