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I have brown algae growing in my tank and I was wondering if Cory Catfish could clean it. If they could not, what other fish, besides shrimp and plecos, could clean the algae? Just a note, my tank is 29 gallons and the algae seems to be growing on the glass.

  • Mollies are herbivores and eat algae from the glass, gravel and plants. I only had black mollies, but I suspect that all varieties do this. Maybe they aren't as efficient as plecos, but are much more mobile in the aquarium.
    – lila
    Commented Nov 14, 2020 at 10:43
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    Thank you lila. I did not know that Mollies would eat algae. Do you know if Mollies get along with guppies and platy fish? Right know in the tank I have 3 male guppies and 2 male platy fish
    – user19212
    Commented Nov 14, 2020 at 19:57
  • Oh you're welcome, and yes mollies get along with these, guppies, mollies and platies are all livebearers, they are all closely related and peaceful. And about catfish cories, I don't think they would eat these algae because, as I observed, cories don't feed from glass walls, they prefer to search for food in the substrate, they are eating what's lying on the bottom of the tank between gravel particles. Also I am sorry I made a mistake in previous comment because technically mollies are omnivores, not herbivores; but what I meant is they feed primarily on plant food (which includes algae).
    – lila
    Commented Nov 14, 2020 at 20:39
  • But I cannot guarantee that mollies will solve this problem, if the environment in your aquarium especially facilitates algae growth then it could turn out that these algae will grow faster than mollies are eating.
    – lila
    Commented Nov 14, 2020 at 20:43

2 Answers 2


Maybe a few herbivore snails? I used to own some and they were pretty good, but they reproduce fast so you might have to take out a few every month, but they scrub away thing rather quickly leaving a clean trail, Cory catfish can do a good job too.

If it’s a big problem, you could shorten the duty cycle of light so that the algae don’t grow as rapidly, I honestly have had that issue before, so if it’s over growing, you could always try that.

Thank you for reading this answer!


Bristle nose placos do a good job cleaning out algae. Make sure to get atleast two to three inches large. Perhaps following link would help not down voting.


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    Maybe could you please insert the part from the linked website that you consider relevant and mark it as quotation, it is appreciated that you attempt to improve the answer, but just linking is sub-optimal because the link could rot away and be of no use.
    – lila
    Commented Dec 22, 2020 at 16:46
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    Hi lila I appreciate your advise, however the whole article is about good, bad and ugly of using bristle nose placo as tank cleaner. I think, I will be doing a disservice to someone if I pick and choose bits from it to fit my narrative. Commented Dec 23, 2020 at 14:06

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