# Black Algae?



## ScoobyDoo27 (Jan 5, 2014)

Over the last month or 2 I have noticed black algae growing on the glass and rocks. It is very hard to scrub off and it's almost like it's abrasive rather than slimy like most of the algae that grows.

My ammonia and nitrite levels are reading zero. My nitrate is probably around a 40 or so and phosphates are around a 2. I change roughly 40-50% of the water every week of my 75g tank.

I have in my tank:
5 red zebras
1 male auratus
2 brichardi
3 synodontis
3 yellow labs
2 hybrids (I'm guessing one is close to a kenyi)
5-1/2 mainganos (baby fish that has survived)

Below are some attached pictures of the tests I did and of the algae. What do I need to do to get rid of this stuff? Thanks for any help.


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## The Cichlid Guy (Oct 18, 2014)

I would keep doing water changes to get your levels under control. You want to keep nitrates below 20ppm. If you continue to have issues once your nitrates are in check, you could try adding a phosphate removing media to see if that is causing the growth.

How long do you leave your lights on?


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## ScoobyDoo27 (Jan 5, 2014)

Water changes more often then weekly? What kind of phosphate removing media? It's something you put in the filter or it's a liquid I put in the water?

The lights are left on from 1pm to 8pm.


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## DJRansome (Oct 29, 2005)

Do 75% water changes every other day until you get to 10ppm nitrates.  Then see what your nitrates are 7 days later. Once you get the level down, 50% weekly might be enough.

I'd reduce the time your lights are on as well...maybe 4 hours daily or less.


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## Mcdaphnia (Dec 16, 2003)

Test the new water you are using for nitrates. In increasing areas of the country, nitrates and phosphates are increasingly high in processed tap water, even in bottled drinking water. The source of these chemicals may be agricultural runoff from fertilized fields and factory style animal husbandry, or from waste water treatment plants that are periodically overwhelmed and divert untreated water to where it may too soon enter rivers and lakes.

If your new water is the problem, you may need to use a denitrator to control the problem. If your new water is proven not to be the problem, then you have already been given sound advice.

Dosing with hydrogen peroxide at rates you can find online, or with a Soechting doser, can be a help with the black algae. You can also remove the affected decorations from the tank and scrub off the algae with a brush and straight 3% hydrogen peroxide solution. Black algae also responds to adding CO2 and/or Flourish Excel, a CO2 source, by bleaching and with repeated exposure, dying. However the last two options will lower your pH at least temporarily to low readings uncomfortable to your fish.


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## ScoobyDoo27 (Jan 5, 2014)

I'm going to say that out of the tap I am getting somewhere between 10-20ppm. The picture I posted above was from right before a water change so that would be the worst it ever gets. But I will never keep under 20 if my tap water sucks. What is this denitrator you talk about? Is it a liquid I put in like my dechlorinator?


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## Mcdaphnia (Dec 16, 2003)

One example is this unit.
http://www.poseidonwarehouse.com/DeNitr ... pureUS.jpg

There are also coil denitrators that can be do it yourself.

Very thick foam (4" or thicker) with very slow water flow through it can also function well as a denitrator after doing it's alternative version of the nitrogen cycle. Large sand filters may also eventually begin to denitrate the water passing though them. Cell Pore used to make four inch slabs of glass? foam that would denitrate fresh water very well. I still have some and nitrate still drops to nothing in those tanks, even after I am gone for the winter and the fish sitter only feeds the fish and does no water changing and filter maintenance only if one clogs.

Instant Ocean make a liquid (Instant Ocean Natural Nitrate Reducer) you can add to tanks that is supposed to denitrate the water. Although decorated solely with with marine themes, it does not specifically say whether it can be used in fresh or saltwater aquariums.


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## BC in SK (Aug 11, 2012)

I very much doubt you can control most algae, especially black brush algae, by limiting nitrogen in an aquarium. 1-2 ppm nitrate is likely plenty, to promote growth, as Nitrogen is seldom the limiting nutrient. Maybe a large algae scrubber would favour the algae to grow in the scrubber and out compete the algae in the tank, for nutrients.
Algae grows from algae. Once you have a type of algae, it is more then difficult to completely eliminate it. Cutting down on the amount of light your tank receives will definitely slow it's growth. But when it comes to black brush algae, I doubt you will completely eliminate it by cutting down on the amount of light. It is extremely resilient, and has been shown in simple experiments to survive weeks of complete darkness! :lol: 
IMO the best way to control it is to have an algae eater. A BN pleco or CAE or a common pleco. IME, a common pleco is by far the most effective at controlling very advanced black brush algae. They will keep it in check, though none of these are likely to eliminate it entirely, as all will prefer the newer growth over older more advanced growth. So if your looking to have a tank with out any algae at all, you may not be entirely happy with the results!


Mcdaphnia said:


> Dosing with hydrogen peroxide at rates you can find online, or with a Soechting doser, can be a help with the black algae.


Yeah, that is one way to try and eliminate it from particular areas. Not sure it is very healthy. Some people have killed fish doing this! Funny the extremes that some will go for aesthetics.Trying to eliminate something that is actually healthy and beneficial to the tank and fish, and end up harming the fish!


Mcdaphnia said:


> Black algae also responds to adding CO2 and/or Flourish Excel, a CO2 source,


Yup, high levels of Co2 has been shown to be able to eliminate black brush algae. Again, not so sure it is the best thing for many fish. Red algae often comes from high current, very high oxygen levels, but also very low nutrient. IME, in my tanks, it grows much better and faster, where there is current in the tank. Near the output of a filter or near a power head, almost always has better growth.


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## Mcdaphnia (Dec 16, 2003)

BC in SK said:


> I very much doubt you can control most algae, especially black brush algae, by limiting nitrogen in an aquarium. 1-2 ppm nitrate is likely plenty, to promote growth, as Nitrogen is seldom the limiting nutrient. Maybe a large algae scrubber would favour the algae to grow in the scrubber and out compete the algae in the tank, for nutrients.
> Algae grows from algae. Once you have a type of algae, it is more then difficult to completely eliminate it. Cutting down on the amount of light your tank receives will definitely slow it's growth. But when it comes to black brush algae, I doubt you will completely eliminate it by cutting down on the amount of light. It is extremely resilient, and has been shown in simple experiments to survive weeks of complete darkness! :lol:
> IMO the best way to control it is to have an algae eater. A BN pleco or CAE or a common pleco. IME, a common pleco is by far the most effective at controlling very advanced black brush algae. They will keep it in check, though none of these are likely to eliminate it entirely, as all will prefer the newer growth over older more advanced growth. So if your looking to have a tank with out any algae at all, you may not be entirely happy with the results!
> 
> ...


We may have to agree to disagree on many of your points. Hydrogen peroxide is natural in aquatic environments, produced by a reaction of sunlight with some organic materials. When we keep fish in water with artificial light or glass filtered light, some of the sun's light frequencies are missing and we are keeping our fish in a situation that is artificial to them. I suspect people who killed fish while using hydrogen peroxide actually did something else that killed the fish, and found a convenient (and perhaps less embarrassing) scapegoat in blaming the death on hydrogen peroxide. The safety margin of manual dosing is pretty high, and the use of a dosing device like the Oxydator ensures that the peroxide is confined in a reaction chamber until it is catalytically converted to oxygen.

Although I have seen nerite snails tackle black beard algae, I am not sure I would count on algae eaters to solve this problem. Even the Siamese algae eater, considered the best algae eating choice for this problem, is not consistently able to control it. Some algae are healthy additions to the tank, but they are the ones that are readily eaten, leaving the tank to species that taste too bad for fish and invertebrates to eat, that can degrade water quality or, like blue green algae, actually produce toxins that poison the tank. The contradictory observations about this topic could be more because we are not comparing oranges to oranges. There could be lots of differences in the tank's parameters and the species of nuisances creating problems in the tank even when the tanks and inhabitants seem superficially the same. Some "algae" actually respond better to antibiotics than to blackouts and other treatments because they are really bacterial colonies and not true algae. I know from first hand experience that prolonged repeated exposure to some of these "algae" can cause allergic reactions. Black beard (Audouinella) is a red algae, debilitates the plants it parasitizes, and produces phycoerythrin. Like the other red algae and the cyanobacteria, it cannot be regarded as a healthy addition to the aquarium. I have raised daphnia, and rotifers for many years. If you feed them algae, you have to switch the algae species periodically because eventually the algae becomes toxic to them.


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## ScoobyDoo27 (Jan 5, 2014)

You guys just went over my head completely ha ha. Just assuming, I would have guessed that the black algae is not good for my tank. It doesn't look good either and I'm not looking to kill my tank over the aesthetics of it either. If the algae won't harm me or the fish then I'm fine just trying to scrub it every week but if it's something that is going to take over the entire tank then I would just like some advice on how to control it. I appreciate the feedback that I have been getting.


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## DJRansome (Oct 29, 2005)

It can get bad enough to clog your filters...I'd try some of the controls suggested.


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## BC in SK (Aug 11, 2012)

Mcdaphnia said:


> I suspect people who killed fish while using hydrogen peroxide actually did something else that killed the fish, and found a convenient (and perhaps less embarrassing) scapegoat in blaming the death on hydrogen peroxide. The safety margin of manual dosing is pretty high


There certainly is some risk involved. Just about every thread on line, about getting rid of black brush algae or treating algae with hydrogen peroxide has somebody claiming it killed their fish. Over dose? User error? If it's not broken down quickly, has a chance of burning a fish's gills. Just a couple examples of numerous threads on line where fish have been supposedly killed by hydrogen peroxide:
A dose that is often "safe" in a heavily infested pond, can be an overdose in a "clean" pond:http://www.koiphen.com/forums/showt...xide-or-sodium-percarbonate-overdose-comments
It can be pretty rough on some plants as seen in this link. A number of threads claim horntwort will often not survive hydrogen peroxide treatment. At the end of the link is someone claiming it killed their fish:http://www.malawicichlidhomepage.com/aquainfo/algae_peroxide2.html
A few people, as well, claimed it killed their beneficial bacteria, and got spikes of nitrite and ammonia shortly after treatment, though the majority claim it has little to no affect.
IMO, should be regarded as a last resort for people with planted tanks. Long term, may not even work as the spores of black brush algae will still be present allowing it to come back at some later date.
From my perspective, simply because it does not kill your fish does not necessarily equal safe nor healthy!


Mcdaphnia said:


> Black beard (Audouinella) debilitates the plants it parasitizes


Yeah, I can see why it is not welcome in a planted tank! :lol: 
But it's far from the only algae that will "attack" plants. 


Mcdaphnia said:


> Black beard (Audouinella) is a red algae and produces phycoerythrin.


So what? All red algae produce phycoerthrin. Nori, dulse, laver all meant for human consumption. Red algae is part of the natural diet of many fish. NLS algae max has 2 kinds of red algae in it. Red algae can be bought at the LFS in thin dried sheets. Maybe somebody could provide links for academic studies on the toxicity of phycoerthrin and at what level?


Mcdaphnia said:


> Even the Siamese algae eater, considered the best algae eating choice for this problem, is not consistently able to control it. Some algae are healthy additions to the tank, but they are the ones that are readily eaten, leaving the tank to species that taste too bad for fish and invertebrates to eat, that can degrade water quality


Black beard algae is readily eaten by most cichlids, gouramis and algae eaters. It is VERY palatable to many fish. It's the expectation that fish that eat it are going to eliminate it on rough surfaces or plants, that gives a mistaken notion that fish don't eat the stuff. I see mbuna, convicts, blackbelts , opaline gouramis ect. spend hours munching on the stuff.....and see the green pooh come out the other end. They can eat rather large amounts of it! They munch on it; they won't remove it entirely from any surface as the "plant" is still there. Then you have algae eaters such as common pleco, CAE and BN pleco all of which can eat HUGE amounts of it. On smooth surfaces such as glass, a common pleco or CAE can eat it down to nothing and eliminate it from the surface. On rough surfaces like fiberglass, a common pleco or CAE can keep it down below 1/8" and on a few occasions eliminate it from a surface. On rocks, I've had it grow thick over 1/2". Eventually a common pleco will spend an afternoon and eat old growth down to nothing (though tiny green specs still remain as the surface is too rough to completely remove it). As far as removing it from real plants, I don't think any of these algae eaters are well designed to do the job, and at least at large size, won't spend the necessary time on these types of surfaces. Can't vouch for a Siamese algae eater as I have never owned one, though it may very well be the best at removing it from plants!


DJRansome said:


> It can get bad enough to clog your filters...


Left unchecked, that is a possibility.
A few years back, lost a common pleco from a heater sticking. My newly purchased pleco went in with my dovii X festae hybrid and became too scared, and hid. My tank got completely over run with black brush alage. Even though I clean my canister every week, there was so much algae in the canister that it restricted flow. Problem was solved very quickly, by moving a larger pleco into the tank!


ScoobyDoo27 said:


> If the algae won't harm me or the fish then I'm fine just trying to scrub it every week but if it's something that is going to take over the entire tank then I would just like some advice on how to control it.


The algae won't harm your fish as long as it can be kept in check. If it grows out of control, and then starts to rot away, releasing it's nutrients back into the water column, then it will contribute to poor water quality. IMO, in the non-planted tank, algae has similar benefits to aquatic plants. Like plants, excess growth has to be removed. If it rots away in the tank, it's actually doing some harm, rather then any good!


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## DJRansome (Oct 29, 2005)

I wish my fish would eat the stuff but I've never seen that...including the BN plecos. I've never had a common pleco.

It seems to come and go in my tanks. When it gets excessive I remove it and squirt like a tablespoon of hydrogen peroxide using a syringe on the 3D background above the waterline when doing a PWC. If the rocks are affected I soak them in a water/peroxide solution in a bucket and scrub.

My plant light bulbs are old and need replacing...do you find that contributes to some kinds of algae or blue-green bacteria growth?


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