Black Algae...

It is highly unlikely that phosphates is causing black brush algae.  And the advice early on to encourage green algae to lose black brush algae is rather silly; problem algae is a problem, whatever type, and as all of it is due to the same thing, it is going to be more advantageous to find what is out of balance.  The balance of light and nutrients is what promotes plants, weakens plants, prevents problem algae, or causes problem algae.
 
On the phosphates, what unit of measurement does your test use?  Diana Walstad has phosphates between 1 and 5 mg/l (milligrams per litre) in her tanks, and no algae issues.  She writes that it is next to impossible to have phosphate so low in an aquarium that it will actually limit algae ( which can occur in nature) as the phosphates would have to be no higher than 0.02 mg/l which is impossible to achieve in a tank with fish being fed.  Phosphates primarily appear in fish food, and if you feed your fish, you will see phosphate at some level.
 
I have had black brush algae appear due to bright or long duration light, excess plant fertilisation, too little light (weak tubes, need replacement regularly) and too little fertilisers.  In other words, anything that causes an imbalance in the balance, so to speak.
 
Byron.

I know the thing with the green algae does sound silly, but it did work. LOL  I have no idea what is out of balance. I got new lights, I am feeding no more or less than I always have, I have more live plants now than I have ever had, and the FloraPride is phosphate free. I do at water changes all the time.  I just have no answer. I just know I can't get rid of it.  It goes away for a little while and then it is right back.
 
I just don't know....

julielynn47 said:

I know the thing with the green algae does sound silly, but it did work. LOL  I have no idea what is out of balance. I got new lights, I am feeding no more or less than I always have, I have more live plants now than I have ever had, and the FloraPride is phosphate free. I do at water changes all the time.  I just have no answer. I just know I can't get rid of it.  It goes away for a little while and then it is right back.
 
I just don't know....

Click to expand...

 
But then you had green algae problems (you said), which is what I meant.  Problem algae is problem algae, and you need to find out where the balance is out and correct that, so you don't have "problem" algae of any type.  It can take some doing, but it is achievable.
 
I still say it is not phosphates, though you didn't say what unit of measurement your test uses.  But if we assume mg/l, then 1 mg/l (you said not at the 2 yet) is certainly not a problem.  I've no idea what level phosphate is in my tanks, but as it is only entering via fish foods (source water is definitely zero, and I am careful with plant additives) there is nothing I could do to reduce it anyway, but it cannot be an issue.
 
First, let's pin down the algae.  I'm attaching two photos of brush algae, is it one of these?
 
Second, what exactly is the light?  I know this is a 4-foot 55g.
 
Third, how much plant fertilisers  and which?  And a photo of the tank would help so I can see the specific plants.
 
B.

 Sorry the pictures are not that good.
 
 
Okay, when it is not too bad, it looks like the second picture you posted, except only at first. Once it is in there for awhile, it gets much worse. It covered the glass sides of the tank. it was all over the plants, and decorations, and heater, and tubes, you name it. The only thing it didn't attach too was the fish.  
 
The first picture kind of looks like it looked after it had taken everything over completely.  But still was not that bushy.
 
I had old lights, which I replaced with Life-Glo  Fluorescent Light Bulbs  
 
I thought I added this, but I guess not, so here goes... I have used FloraPride from Tetra for years and I have used the same foods for years also. But the problem only started a little over a year ago

 
 
 
On the phosphates, what unit of measurement does your test use?  Diana Walstad has phosphates between 1 and 5 mg/l (milligrams per litre) in her tanks, and no algae issues.

Click to expand...

A lot of other people would disagree including me and Akasha. We both had high phosphates (due to different causes) and once we got the levels down (using different methods) much of the algae vanished.  I never had levels that high as Diana reports.   The reason phosphates are not causing a bloom in Diana's tank is because it is symptom ot the problem but not the cause.  In her case she might be short of some other element in here tank such as iron, copper, or calcium.  without any one of those plants will die.  That is preventing the Algae to grow in Diana's tank.  For me I had low nitrogen and low copper levels.  I had multiple types of algae in the tank. Once I corrected those problems phosphates dropped to low levels, the algae died, and my plants are still growing very well.   
 
How do I know I was short on those elements?  I am using RO water which is almost pure water.  I looked at my fertilizer label and it had no copper but everything else plants need.  I switched to one that had the same ingredients plus copper.  Phosphates started to drop but inconsitantly.  My nitorgen was very low so I added additional nitrorgen. The fertilizer I was using did have a small amount of nitrogen but my nitrate test was reading zero.  I concluded my plants didn't have enough nitrogen to remove all of the phosphate.  So I added nitrogen and my phosphates crashed.  My plants continued to grow.
 

 
As your tap is ok I'd be going through the ingredients in the food ... maybe look to switch brands once you've used up your current supply.

Click to expand...

All plants and animals need phosphorous to live.  All food is mad from plants or animals.  So no mater what food you buy you will always be adding phosphate to your aquarium.  
 

 
 
I use Tetra ForaPride. It says on the bottle that it does not contain Nitrates or Phosphates. 

Click to expand...

Check your bottle label and look for a list of elements it contains and compare that to SeaChem Flourish Comprehensive, a complete fertilizer.  if your tetra fertilizer doesn't list what it has or the listis incomplete it might be the cause of your problem including the high phosphates.  Sadly many fertilizers on the market today are missing many of the elements plants need.
 

 
 
Good post Steven but I just wanted to add - to check any fert you are using to see if it contains phosphate. Some do, some don't.

Click to expand...

Yes ideally we want a fertilizer that has everything except phosphates.  However I have not found one.  Those that say they don't have phosphates often don't say exactly what is in the bottle.  I f you know of one then let me know.  However if your high phosphates are caused by a shortage of some other element in the water than the small amount of phosphates in SeaChem Flourish Comprehensive would probably not make the problem worse while the corrected shortage would help.  I have been experimenting with using SeaChem trace as a base fertilizer and then adding other ingredients to make it a complete fertilizer without any nitrogen, phosphates, and potassium.  I think I need to add potassium to it.  Some algae came back and my plants looked like they were suffering.  So for now I have switched back to Flourish Comprehensive.

okay I'm gonna wade in here with some photo's. This is what my tank looked like when my phosphates were off the scale
 

 
 
High phosphates cause black algae. I'll argue it till I'm blue in the face. My local pet shop (which I can see from my flat) uses our tap water for it's tanks and every tank has black algae. I've spoken with other fish keepers from my town and they all complain of their tanks being covered in black algae. Even PFK magazine states that high phosphate = black algae.
 
This is a photo of my tank taken just this week
 

 
 
Still a small amount of black algae but with the phosphate remover and 3 SAE's it's under control

Okay, when it is not too bad, it looks like the second picture you posted, except only at first. Once it is in there for awhile, it gets much worse. It covered the glass sides of the tank. it was all over the plants, and decorations, and heater, and tubes, you name it. The only thing it didn't attach too was the fish.  
 
The first picture kind of looks like it looked after it had taken everything over completely.  But still was not that bushy.
 

Click to expand...

 
Fine, I was just confirming we are dealing with brush algae.
 

I had old lights, which I replaced with Life-Glo  Fluorescent Light Bulbs
 

Click to expand...

 
Algae can appear when the lighting becomes less intense with age, and replacing the tubes/bulbs will correct this problem.  I replace mine every 12 months, on average; I let them go one year to see, and when I got to month 14 and 15, algae began noticeably to increase; replacing the tubes resolved this and the algae stopped.  Light is one aspect of the balance, and a very important aspect.  Intensity and duration factor in, but one does not make up for the other, i.e., if the light is too intense or too weak, changing duration will not compensate.
 

I thought I added this, but I guess not, so here goes... I have used FloraPride from Tetra for years and I have used the same foods for years also. But the problem only started a little over a year ago
 

Click to expand...

 
More on balance.  Depending upon the plant species, the number of plants, the fish load, and the source water, it is possible to have a thriving planted tank with no plant additives (fertilisers).  As any of these factors changes, adding nutrients may be necessary, but you need to keep them in proportion.  Phosphates keep getting mentioned, but this is exactly my point--too much phosphate (phosphorus) is causing the imbalance and algae takes advantage.  The same thing will occur if you have too much iron.  Or too much Flourish Comprehensive (this caused terrible brush algae in one of my tanks).  Or too much light intensity, or too little.  Or organics increase.
 
Byron.

My phosphate level has dropped, so I have some hope that will help.   I did a good cleaning, scraped the walls of the tank good. It was on them again worse than I though.   
 
Some of my plants might die,( I hope not, but they were going to die from the black yuck anyway, ) but I took a few of them out of the tank and soaked them in a bath of water and peroxide.  The stuff pretty much just fell right off them.  I let them sit in the bath while worked on the tank and then I swished them around in the water and poured it off and the water was just a nasty dark color.  I rinsed them again and put them back in the tank. They look good, but only time will tell.   I have some hornwort that floats and that black stuff just gets all over it and kill wherever it grows. They are floating green and pretty again now. I hope it lasts.
 
I am going to look for some of the Siamese algae eaters when I go to town this week.  And I will acclimate them if the ph is a problem.  It has dropped. The water guy did something because it is at least not off the chart anymore. It is still reading 7.8 and 8.0, out of the tap but that is an improvement in that area at least.
 
My tank just looks so good right now. I had no idea that that horrid stuff was on the glass that bad again.  

I don't know what other fish you have in this tank, so make sure the SAE will work.  This is a shoaling species, and should have five or six, sometimes fewer work (Akasha has three I believe) but in other situations this causes real issues for the fish's natural hierarchy.  But they get to six inches, so not a small fish.
 
I've never known brush algae to come off plant leaves by any method.  Wondering now if this is something else...can you post a close-up but clear photo of a plant or plant leaf with this algae?

I will try to get a picture..   I read online that peroxide, sprayed on the algae while in the tank, would get rid of it. I did not want to start spraying peroxide in my tank, but I thought it was worth a try anyway.  It didn't all come off, but a lot of it did

Here are 3 pictures. It is not as bad as it once was, but it is trying to make a come back.  That little amazon sword in the sand had nothing at all on it about a week ago. That is how fast it is growing.  The hornwart that is floating is just getting covered in it. That is not the bunch I used the peroxide bath on.

OK, I think we are still on the right ID.
 
Plants like Hornwort (Cabomba is another, and Wisteria) do not do well with troublesome algae as the leaves are so small and delicate.  Might be worth keeping a couple stems in another tank if you have one, where it can be free of this, until this tank is cleared up.
 
Is this the 55g tank?  Is the Life-Glo T8 or T5, and how many tubes (4-foot I will assume)?

Yes, it is the 55g.  The lights are T8 and it is 2 tubes.   That is a good idea on the hornwort. I do have another tank and at this time no fish are in it, just water and some plants.  I just hope that it will clear up in time.  I have fought it for so long.

julielynn47 said:

Yes, it is the 55g.  The lights are T8 and it is 2 tubes.   That is a good idea on the hornwort. I do have another tank and at this time no fish are in it, just water and some plants.  I just hope that it will clear up in time.  I have fought it for so long.

Click to expand...

 
My 70g, which is 4 feet in length like your 55g, but is wider at 18 inches (the 55g is I believe 12 inches width?) has two T8 tubes, 4-foot.  I can only have them on for 7 hours or brush algae increases.  My other tanks are on 8 hours.  You may want to reduce the duration if it is longer.

I thought plants need 10 to 12 hours of light a day? This is what I thought and so my lights stay on 11 hours at day. They are on a timer so I never have to think about turning them on or off