Freshwater Aquarium/White dust


QUESTION: I have what I can only describe as white dust floating on the surface of my 60-gallon freshwater aquarium. It looks like chalk dust. The water is healthy. My tank contains discus. I do have a case of fin rot that I am dealing with. Are these two issues related? How can I get rid of the "dust"? Is it an algae? I am using a fine-meshed net to capture and remove some of the dust, with some (but not total) success.

ANSWER: Hello,

It could be several things. If you have hard water, it could be calcium build up. Protein can also build up, create a film, and then form spots that look like dust. If it is not calcium or protein and this is not a problem you had before, then it is likely fungus.

---------- FOLLOW-UP ----------

QUESTION: Thanks. My local stores weren't very helpful. Do you have any suggestions for what to do now?

You could try:

~ Doing a major water change. You can also try inverting the siphon so you siphon water from the top instead of the bottom like it is usually done.
~ Make sure you're not overfeeding.
~ Try pet store products made to clear water, but question whether or not those would work.
~ Change the filter media. A new cartridge might help.

You could also just wait and see. It might clear up whenever the fin rot clears up.  

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Elizabeth Turbyfill


I am available to answer any questions regarding Betta fish and goldfish. I will be able to answer questions ranging from basic husbandry to health issues and more. I have a fair amount of knowledge regarding keeping freshwater fish in general as well, excluding cichlids. If you have any questions about species compatibility, maintenance, health issues, et cetera I can help. If there is a question that I do not know the answer to, I will look to reliable resources to find the answer.


I have kept numerous Betta fish and freshwater aquariums for several years, and have spent countless time researching them.

I am a member of a fish forum named Tropical Fish Keeping that I highly recommend to people who keep aquariums or just have complex questions that cannot be answered here.

I am currently attending East Tennessee State University for a bachelor's degree in Computer and Information Science.

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