Fish Keeping and Aquascaping Blog

May 4, 2010

Tackling the Black Brush Algae ( BBA )

For a planted aquarist, there is not greater displeasing sight than the sight of algae invading his tank. Every planted tank enthusiast would, at some time or the other , have issues with algae in his tank. These algae are not only displeasing to the eye, but also take over the tank fully if not brought under control quickly.

Among them, the Black Brush Algae or the BBA is one of the most difficult algae to deal with. Some refer to this as Black Beard Algae too. This algae starts as a small black brushy patch on a leaf or decorative item, and then spreads rapidly all over the aquarium , turning everything it touches into a black carpet. I’ve seen this BBA grow even on my aquarium glass and the silicone tubing’s inside the tank. It is generally first seen on the leaves of slow growing plants such as Anubias and Ferns.

Here is a pic of how the BBA would look in a aquarium.


There are many causes and reasons cited for the presence and spread of this algae in the tank, and I would not like to go into the details of these causes. I would just like to mention here that nutrient imbalance and improper ( excess ) lighting are  the main cause of this algae .

I would like to detail here the various methods in use to prevent the spread of this algae and the methods that I used to control BBA in my tanks. ( Note that we do not talk about methods of preventing the occurrence of BBA, since BBA spores ( or for that matter any algae spores )  are present in almost all aquariums . Hence ‘control’ is a more appropriate word than ‘prevent’ in this context. )

a) Nutrient and Light Control

Excess light and nutrients in the tank are considered to be the main cause of BBA. For most aquarist’s it’s difficult to derive/predict the exact amount of nutrients required for the plants in the aquarium. We generally end up over dosing or under-dosing the nutrients. Same is the case when it comes to lighting, in terms of predicting the wattage( or lumens ) or the photo period required by the plants. Since excess of these generally leads to algae bloom, it’s better to err on the lower side. Hence, If it’s a newly set-up tank , start with small quantity of dosing and lower lighting period ( since the wattage is generally fixed on buying a lighting fixture. ). These can be gradually increased after seeing the response of the plants.

Similarly, on the out break of BBA, a sure-shot way of controlling the spread of BBA is controlling ( reducing ) the lighting period and dosing levels. Sure, your plants might get affected a little, but in my opinion , it’s better to have slower growing plants with no BBA, than having fast plant growth with equivalently fast spreading BBA in your tank. Since it’s very difficult to predict the ‘exact’ levels of nutrients and lighting period that would make the BBA disappear, at the least, reducing dosing and lighting period may help control the spread of BBA to a large extent.

You can then try some of the below methods to completely eliminate BBA.

b) Introducing BBA eating fish

Many aquarist’s have had varying degree of success in tackling BBA with algae eating fish. Some have reported no success . A few fish like ‘True’ Siamese Algae eater, Black Mollies, American Flag fish, Swordtails etc are know to eat BBA in the aquarium. The ‘True’ Siamese Algae eater is the popular choice among aquarist’s for controlling BBA in a planted tank. ( In some cases, the True SAE is also know to eat away the moss in the tank, as in my case ) . On the contrary,  I have also had fellow hobbyist’s complain that they have never seen these fish eat any BBA in their tanks. I have used Black Mollie successfully in reducing the BBA from my tank.

The trick here is to keep the BBA eating fish hungry. A well fed fish in a tank rarely gets interested in eating the not-so-delicious BBA. So you have to make sure that your keep your BBA eating fish hungry enough for them to go after BBA. But the catch 22 situation here is that you have to keep the other fish in the tank well fed, but the BBA eating fish hungry. How you accomplish it, is left to your creative thinking.

Some ideas include transferring your other fish from the BBA infested tank into another temporary tank and keep only the BBA eating fish in the infested tank and feeding them minimally.

c) Bleach Dip or Potassium Permanganate dip

Another quick way to get off BBA is to dip the BBA infested plants or decors in a 1:20 home bleach solution. Home liquid bleach ( i.e liquid cloth bleach )  is available in India under different brands such as ‘Rin Aala’, Robin Liquid Bleach etc . Though this is a very quick and cost effective method to get rid of BBA, it works only if the affected plants or decor can be taken out of the aquarium for the bleach dip. Hence it can be used for affected plants such as Anubias and Fern , but cannot be used for deeply rooted plants since you cannot uproot them as and when required.

Dip the affected plants or decor in the 1:20 bleach solution for about 10-15 mins and then thoroughly rinse the plant/decor in running water. Remember, bleach, if it enters your tank, can be dangerous to the fish in the tank. You can put back the plant/decor into the tank after rinsing them. The algae turns whitish in the next few days and can be removed easily by hand/brush or can be left to slowly fall off from the infected area.

The time for which you dip plants in the bleach solution depends on which plant is being dipped. Sturdy plants with stronger leaves like the anubias and fern’s can be dipped for upto 15 min, whereas soft leaved plants like bacopa and crypts should only be dipped for 3-5 min. I have lost a whole bunch of Bacopa Monarie after I left it in the bleach for 15 mins. ( I was rescaping my old tank and decided to uproot all my infected plants ).

The same effect can be obtained using diluted Potassium Permanganate ( KMnO4) as the dip solution. But bleach is more effective and a cheaper option.

d) Hydrogen Peroxide Nuking

For plants that cannot be taken out of the tank for a bleach dip, another solution is to spray Hydrogen Peroxide ( H2O2 )  to the infected area using a syringe. H2O2 is available cheaply in all chemist stores. Fill a 5ml syringe with H2O2 and spray it to the affected area in the tank. ( Remember to switch off the filter before doing so, else the water current will spread out the sprayed H2O2 ) . This is termed a ‘nuking’ of BBA. ( Never understood why it’s called so 🙂 ). After ‘nuking’ you can see a lot of nascent oxygen bubbles emanating from the area to which H2O2 was sprayed. This resembles the bubbles coming out of a champagne glass. Over the next couple of days, the BBA in this area turns whitish or pinking as in the case of bleach dip and fades away.

I have had minimal improvements with this method of BBA control. The issue with applying this method successfully is that since H2O2 is introduced directly into the tank, you have to be very careful of the quantity introduced( sprayed ). Since H2O2 can be harmful to the fish in higher concentrations, you can use this method on only smaller and restricted areas in the fish tank. Never-the-less, it still works fine on smaller patches on BBA infestation. You also need to be careful if you have delicate ‘soft tissue’ plants like Riccia in the vicinity of the place where you plan to inject H2O2. Riccia reacts badly to even the slightest dose of H2O2. My entire Riccia tied onto a stone turned pale yellow and withered away when I injected H2O2 on  nearby Anubias leaves covered with BBA.

Using the above methods, an aquarist  can successfully control and eliminate BBA from his prized tank.

There may be other methods too to control the BBA. If you know of any other method, do share it by dropping a note.  Suggestions or comments on this topic are always welcome.

Prabhu M



  1. Very helpful information on BBA,
    Thanks a lot.

    Comment by Raushy — July 23, 2010 @ 1:17 am | Reply

  2. Nice Info!

    My tank has been overrun with BBA and I am at my wits end. I keep my tank in pristine condition. I do water changes every week and my parameters are good, so I assumed it was additional nutrients (phosphates, etc) in the water and adjusted accordingly. No luck!

    I’ve tried everything from to the 72 hour blackout technique to chemicals, and the algae is still going strong. I’ve decided to try the bleach dip as a last resort. Hopefully, my plants will survive the treatment.

    Comment by Lana — July 28, 2010 @ 4:59 am | Reply

    • Lana, one of the main reason for the growth of BBA is fluctuations in CO2 levels in your tank. Keep the CO2 levels constant and close to 30 ppm as much as possible.

      Comment by Prabhu M — July 28, 2010 @ 10:14 am | Reply

  3. Hi Prabhu,
    I have 2 queries.

    1. How do you check the CO2 ppm?
    2. For H2O2 “nuking” what is the concentration of H2O2? I have a H2O2 solution from the medicine shop which says it is 6%v/v… is this safe to use directly?

    Comment by Nilanjan — June 14, 2011 @ 4:22 pm | Reply

    • 1. Using a drop checker ( available at an aquarium store )
      2. Yes, you can use it directly.

      Comment by Prabhu M — September 22, 2011 @ 11:04 am | Reply

  4. I have BBA problems. I started dosing with API’s CO2 Booster. I use it twice a day when the lights come on (I do a five hour lighting and six hour lighting session). When I read about CO2 fluctuations, I start worrying that this method is causing or contributing to it. Any thoughts? RER

    Comment by RER — December 23, 2011 @ 8:20 am | Reply

    • Though I have not used API’s CO2 booster myself, I can tell you that CO2 fluctuation on the higher side should not lead you to BBA, but might be harmful to your fish. I suspect that you are using the API Booster as your CO2 source and not as a CO2 booster to your regular CO2 supply ( via gas ). If you are, then your supply of regular CO2 may not be sufficient.

      Comment by Prabhu M — December 23, 2011 @ 7:26 pm | Reply

  5. my Jewel trigon 190 was full of Black beard, plants,gravel,etc..i went away on a three week holiday and didn’t have anyone to look after fish while away,i normally feed flake in the morning,and frozen foods in the evening,and do a 20% water change every week..while away i used a jewel auto feeder on top of tank which fed flake/pellet mix,i also added “Tetra Easy Balance” for 2 weeks before hand..when i got back from holiday all fish were fine and to my amazement all BBA was gone, not even 1 hair was left,i think it was the “easy balance” that did it.. 3 months later a tiny bit has returned,will use “easy balance” again ..hope it works as good as first time.

    Comment by steve. — May 10, 2012 @ 8:55 pm | Reply

    • Thanks for the comment about leaving the lights off and using “tetra easy balance”. I’m going to leave my fish tank light off for about 3 wks and see what happens. This algae doesn’t seem to bother the fish and my oscars are laying eggs every 30 days. It bothers me though! I want green algae if any. I have plecostomous in my tank but their not eating the black brush algae. It’s on everything! Hoses, deco’s etc. My fish are very healthy. Is this a bad algae to have? Becky

      Comment by Becky Chandler — September 11, 2012 @ 1:18 am | Reply

  6. […] Black Mollies would survive in your tank with your current fish load. They too like BBA. I thought this write up on nuking BBA was interesting. Although I have never tried it. __________________ Inspired […]

    Pingback by My 125G Dream - Page 3 - APE - Aquatic Plant Enthusiasts | A Planted Aquarium Community — August 6, 2013 @ 7:30 am | Reply

  7. I am going to speak in favor of BBA and most folks on this forum may not agree with me. I used to fight it like mad doing all sorts of things to try to maintain a “clean” aquarium. Then, I realized, by trying to totally eradicate algae I was trying to create a system that appeals more to humans and not to the fish. Algae is a natural part of the real fish world. An over abundance of it is definitely a sign of your tank being out of balance in some way, however, I’ve learned to live with moderate amounts of BBA and my tank parameters are perfect. True, it grows on the glass, the plastic plants, the ornaments. I do have to stay on top of it to keep it from becoming too aggressive. But, a lush carpet of BBA on the top of a flat rock is very natural. It’s fun to watch the bottom dwellers slide through it like a soft carpet.

    I’ve found that mollies and platys both will munch on BBA. I recently had a stint of time where I was caring for a sick family member for about 45 days and my tank was sorely neglected while I was gone. There were no water changes and none of the fish were fed. The light had been left on the whole time. When I returned, the water was about six gallons low in my 29 gallon tank, but very clear, the algae was thriving, and my 3 platys and 3 harlequin rasaboras were fat and hardy – though they were happy to have flake food again.

    Comment by kathine — January 11, 2014 @ 12:34 am | Reply

    • I’d also like to add a side note to my above comment – BBA growing on real plants is a pain. I do sympathize with anyone trying to grow certain slow growing real plants in a tank that has BBA. My plants are fake and I keep the gravel turned from suction cleaning otherwise it would cover the bottom. Keeping your tank maintained with regular water changes, not over feeding and moderating the light will certainly help keep BBA in check, but I have never been totally free of the stuff for 20 years.

      Comment by kathine — January 11, 2014 @ 12:38 am | Reply

  8. I have this black algae on plant leaves and artificial rock, but not on glass or gravel. I recently introduced Neritina snails. True, they do not clean the plants but they do a wonderful job on the rocks. They’re all cleaned up. My otos and siamese algae eaters do not touch the black algae

    Comment by Roland — January 21, 2014 @ 10:34 pm | Reply

  9. I bought some 4 SAE and they did not touch the BBA even if i did not feed them for 2 days, probably were some “fake” SAE, so you have to be very carefully when you buy SAE.

    Comment by Iwagumi — June 18, 2014 @ 5:52 pm | Reply

  10. I had black brush i bought azoo black brush algae killer and within 2 weeksthe BBA was gone.

    Comment by Kimberley rauchelle — August 31, 2015 @ 10:20 am | Reply

  11. I had a really bad infestation that literally appeared overnight in my tank, so me and a friend scrubbed my bogwood and gave it a boil as well as rinsing the substrate in boiling water from the kettle. That was at least a month ago and now there’s only a small amount growing but I got given some plants that were truly infested with the BBA and decided to get some red cherry shrimps. Best decision ever, they love eating it and clean your tank. Win win for sure 👍

    Comment by Loopy — September 30, 2015 @ 3:01 am | Reply

  12. Very easy solution :-

    1) Fill up a syringe with Liquid Carbon (Azoo or Flourish Excell – This is available in local fish shops that generally keeps plants too)
    2) Spray in small quantities on your BBA directly.
    3) Introduce Siamese Algae Easters (Prefereably young ones)
    4) Keep calm and Relax – You tank should be 99% cleared of BBA by the end of 1 week

    Comment by Shilpa — March 17, 2016 @ 4:44 pm | Reply

  13. I have all fake plants and always bleach dip them when i see algae growing like crazy on them. Im in the middle of doing my decorations right now, but question is how do i get bba off my rocks.

    Comment by Jess — July 13, 2016 @ 2:43 am | Reply

  14. well I learnt a lot today from you guys,I don’t think that I shall ‘panic’ so much about my infestation of BBA now…it looks awful but hey,the fish seem happy enough..I am leaving them all (5 x5ft tanks) for one week without lights or food next month,usually it would worry me,but after reading your comments I am just going to let it be and see what happens..

    Comment by Anna johannessen-adams — August 28, 2017 @ 7:35 pm | Reply

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