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BBA Gone wild since changing to LED


20 Dec 2008
I have a 200L 100cm aquarium. I previously used 4 x 39W T5 lights , 2 on for 8 hrs and all 4 on for the middle 5 hrs. I recently changed to the Chihiros A901 running for 8 hrs. I have been running on full power and my BBA has got out of hand- the LEDS do not look brighter than the T5s, hence me running on full power, I have knocked it down 2 levels with little effect.I cant get any carpeting plants to grow.

So have I too much or too little light? I was considering buying another Chihiros light but running both at lower power to give a better spread of light.
Any ideas?

CO2 20PPM, PH 7.0 Hardness off the scale-London tap water
4 x 39w t5s would be roughly 12000lumens depending on model, reflector etc.

The A901 is rated at just over 8000lumens.

So peak intensity has probably dropped measurably.

Could you grow carpeting plants before? I.e. with the t5s

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I have never been able to grow carpeting plants. Using JBL aquasoil, FE CO2. EI using Aquarium Plant Food as per instructions.

I must be doing something wrong!

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I have never been able to grow carpeting plants. Using JBL aquasoil, FE CO2. EI using Aquarium Plant Food as per instructions.

I must be doing something wrong!

What depth is the tank?

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About 50 cm. Hooded tank so lights immediately above water through cover glass.

My parameters today are (according to JBL proscan strips) are:-

Nitrate 18
Nitrite 0
GH 14 D
KH 15 D
PH 7.0
CO2 35 ppm (a bit higher than usual- just changed bottle so may need adjusting)
One was new, one was 2 years old and the rest were older I think. That's what prompted me to go for the LED, the tubes were getting on.
What doesn't, the BBA or parameters?
The BBS with potentially less light.

But with your tubes except one being over a year old could explain the BBA. As your old tubes had poor output. Think it's normal to replace them yearly to keep the output up.
So your new LED (even though on paper) have a lower output in lumens, they may actually have a higher lumen output due to your T5 tubes being mainly old.

If that's the case a decrease in photo period or LED intensity should help resolve the BBA with time.

Some LCO2 might help long/short term too.

But no expert here, just going off my reading.

Sent from Mountolympus via neural interface
I have been using liquid Carbon from TNC, and spraying with Hydrogen Peroxide, it's stubborn stuff!
One was new, one was 2 years old and the rest were older I think. That's what prompted me to go for the LED, the tubes were getting on.
I think the t5 setup should have been enough to grow a carpet - even with slightly older tubes. The led may be borderline. I would look for other problems in the tank such as flow.

As far as BBA is concerned, I have an ongoing battle with it as well. Like you, London tap water.

Everyone will give a different opinion but I read some time ago reports of BBA outbreaks in unheated tanks during the winter (this was US fishkeepers, southern states - so just cooler in the winter). So I increased the temp from around 23c to around 26.5c. I still get occasional outbreaks (every 4-5 months) but it is manageable and generally disappears after a few weeks.

Whatever you do to try and control it, make sure you only adjust one thing at a time and give it time (weeks) to assess the impact. If you change multiple parameters you'll never figure out what actually works for you.

Regards, Mark

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Flow should be OK- have a decent external supplemented with a Hydor circulation pump.
Algae Guide

This algae guide is mainly aimed at the high light tank being dosed by Estimative Index.
(But is applicable to any Carbon enriched tank)

Black Brush Algae, BBA

Description Often grows on leaf edges of slow growing plants, bog wood and mechanical equipment. Also sometimes it grows in fast flowing areas of the tank. Grows in clumps or patches of fine black tufts up to about 0.5cm long.
In a high light tank it is an indication of low or fluctuating CO2 levels or not enough water circulation around the plants. In a low light tank it is often due to changing CO2 levels.


In a high light tank you will need to increase your levels of CO2 and/or improve water circulation around the plants. Scrub and cut off as much as you can first. Increase levels slowly to 30ppm or more but watch the fish to see if they are respiring heavily. Make sure you have good water flow around the whole tank along with some good surface movement. Adding a powerhead may help.
If you have a low light tank without CO2 injection then not doing any water changes will help. This is because tap water often has lots of CO2 dissolved in it which causes CO2 levels in your tank to fluctuate.
The algae respond to this a lot quicker than the plants do.
Siamese Algae Eaters are known to eat BBA so can be used to control this algae.
Overdosing Flourish Excel, EasyCarbo or TNC Carbon will clear it up.
Light and its intensity can be a very confusing phenomenon, it is very hard for us to determine it's intensity with how our eyes percieve it.

I experience this with one of my low tech tanks standing under a roof window. Thus it recieves a lot of natural light from above. Last year around march i had a significant BBA outbreak and switched off all artificila lights. And actualy was astonished how bright the tank was lit by the roof window, switching lights on and off didn't make a difference in how i percieved it. A few weeks after leaving the lights off, the BBA became less and when the fall arived in october it was gone and i switched the lights back on. Now we are mid april again, same story, BBA is comming even the snails are growing a beard and i switched off my lights again and the tank is only lit by daylight.

Still it is filtered day light the roofwindow is opague and even i do not see the difference the extra artificial lights is obviously to much and favors BBA. What baffles me a bit, is the pond like bath tub i have in the garden. It stands on a sunny spot on the terrase and gets full blast daylight and sunlight at sunny days. And i never ever have seen a strain of BBA in it.

I only have cluess to think about why and since algae and plants are same family and what makes them thrive is a combination of light, fertilization and temperature as far as we know.

If the trigger to cause BBA to thrive only would be light, than the pond should have it by now, but it doesn't. So their most be going on something else.. And i realy only have cluess. The outdoor pond is despite it has the most light off all it is relatively much colder than the indoor tanks.. That is one clue that could have an influence on BBA. The indoor tank has it with less light but it's a stable 22°C.

I don't believe it is realy co2 related only, because the pond doesn't get it and the low tech neither.. Both have the same water and both have the excact same Ph fluctuation during the light cycle. Co2 might be only playing a role if you additionaly put it in, but if you don't there still is a BBA trigger to cause it to thrive.

That leaves me with Ferts, light and temp.. Of which i think it's the later 2, light and temp.

But what the proper combination is beats me to the punch.. I have another low tech planted shrimp tank with only about a 1500 lumens led light at 60%, no ferts and a stable 25°C.. I throw in BBA infested plants and 6 weeks later they come out clean. That little tank is my prooven BBA exterminator.

My fertilized high tech tank with a stable 0.5 pH drop with co2 has over 10000 lumen led running at 60% - 40cm high above the tank and 23°C and it grows BBA, not thriving but some older leaves now and then show a little.

So that's 3 tanks 1 pond and each has it's differet BBA issue.. And i didn't got very much wiser tho.. But light and temperatur has my focus i think the culprit hides in these 2.. :)
I have come to the same conclusion, As regards the trgger i have no idea. I get BBA/GSA on the dragon stone in my tank,I have tryed all ways to get rid of light intensity diff flow pattern,Co2 levels fert levels you name ive tryed it, It never seems to go away completely it is a PITA lol..
As its only really on the dragon stone i get it the guess i have come to is it is something in the make up of the stones that attracts it???
The best way i have found to control it is spot treat with h2o2 then a good scrub with a tooth brush then spot treat with liquid carbon. Concentrated one two punch if you like.
I do this once a week at the water change it keeps it at bay.
Obviously the post of others whom i have great respect for their experience and wisdom for the treatment and causes off BBA (which i have yet to have/treat, which I'm sure i will have to combat with time.) Carries much more weight than my thoughts.

You changed the light to LED which lead to the expensive BBS so the main thing which tipped the balance must off been the light.
You went from a relative uniform light source to a more focused/beam source yet your carpet is still struggling. Maybe your first thoughts of two LED units at lower intensity may be the way forward at a cost.

That's assuming (which i think) the light source is the only thing you changed then you got the BBA bloom.

Sent from Mountolympus via neural interface
I have gone for the option of another Chihiros 901, with both on a lower power. One immediate advantage is the tank looks better. One lighting unit in a hooded tank essentially meant all the fish were in shadow when viewed from the front.
It's been in since the weekend so will see how things go.

I've added the extra light, a month later I still have rampant BBA. At a loss at what to do next! More/Less Light? More/Less ferts? More/Less water Changes?