# Brown (and green) hairy algae



## andrenm (Jun 25, 2020)

Hi,
I have a new tank (almost 4 months old) and I had (have) some problems with algae.
It's a 50 liters cube (40 liter display) with the Walstad method and after 1 month I started to see some brown hairy algae on the taller plants and in the roots of floating plants.
On the 2nd month I did my first water change (12 liters) and on the next day I saw an explosion of brown algae (now almost everywhere), every week I scrub the algae but it always comeback on the next day. (pics 1 and 2 are 2 days after a clean up)
After almost 1 month i decided to test Seachem Phosguard and like magic the algae vanish in one week (I removed it after that), but now I have another problem, on the same spot a green hairy algae is growing. (pic 3 is one week after a clean up).
I have a 10w led lamp that is on 8h a day (4h on, 4h off and 4h on) and besides these hairy algae I do not have any problem with algae.
The water here (São Paulo/Brazil) is very soft (4-5 dgh) and the plants are not so fast growing so maybe they cannot compete with the algae.
Did anyone have problem with these algae? There is a better solution than Phosguard? Maybe the Phosguard cause the green algae?
Thanks


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## hoppycalif (Apr 7, 2005)

Plants need phosphorous to be able to grow. Removing virtually all of the phosphorous in the water is very likely to stunt the plants, leaving them more susceptible to algae. Also, a shortage of phosphorous (phosphates) will encourage "green spot" algae to grow. Phosphates are not an enemy, so you shouldn't try to remove them.


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## andrenm (Jun 25, 2020)

hoppycalif said:


> Plants need phosphorous to be able to grow. Removing virtually all of the phosphorous in the water is very likely to stunt the plants, leaving them more susceptible to algae. Also, a shortage of phosphorous (phosphates) will encourage "green spot" algae to grow. Phosphates are not an enemy, so you shouldn't try to remove them.


Thanks for the advice, I will do a water change to replenish the phosphorous, one last question do you have a suggestion on how to deal with the brown algae without Phosguard?


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## mistergreen (Mar 3, 2007)

a couple of oto catish will eat brown algae.


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## andrenm (Jun 25, 2020)

mistergreen said:


> a couple of oto catish will eat brown algae.


Thanks for the tip, I did some research and some people say that they do not eat hairy algae (that's my main tank problem) and since they are a school fish I would need to have 5-10 fishes.
My tank is very small (40l cube display + 10l sump) and I thought that add that much fish would make very difficult to add another fish.
And my last concern is that because this fish is native from Brazil most fishes found in store are not captive breed.
Do you think that they can eat the hairy algae?


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## mistergreen (Mar 3, 2007)

You can try shrimps and snails if you don’t want oto.


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