Thick Green Algae?

[phoneticerror]

Hi guys,
 
I've had my 125L freshwater tank set up for just over three months now... The community is getting on very nicely, but over the last 2 weeks I have been getting a thick carpet of green gunk across the sand and on some of the plants.
 
I perform PWC's at least once a week, and also vacuum the substrate weekly. Every time I remove this from the tank, it reappears within 48 hours, and is getting out of hand. Is it a form of algae? I assume I need to buy some form of treatment for the tank, but I'm not sure what I'm looking for.
 
My nearest LFS is a Pets at Home, and I've noticed that their staff hardly know anything, so I'd appreciate some help from you knowledgeable folk please.
 
Here is a pic of it...
 

 
It started to appear shortly after I added two corys, and I have been feeding food pellets. Could this be related? I've not been overfeeding them.
 
I also have a few nerites, but nothing is eating this green stuff, so I'm assuming it isn't 'good' algae.
 
Recently, I have lost 3 neon tetras and a golden barb (the golden barb was unhealthy from day one, I think he had problems that were unrelated to my tank as he was incredibly scrawny and didn't put on any weight in the month I had him, whereas the other 2 grew beautifully).
 
Any help would be great.

 

[techen]

First thing is first, How long do you keep your lights on for?

 

[DrRob]

Difficult to tell from the picture but blue green algae is a possibility. It would be slimy to touch.

 

[Lunar Jetman]

That looks to me like BGA or Cyanobacteria. It's not strictly an Algae but a bacteria. It also can smell pretty bad too. It's often caused by low nitrates or poor water flow. Nothing will eat it either. As Dr Rob says, it will be slimy to touch. When removing it can even grow back within hours.
 
Unfortunately the only real way to get rid of it is to perform a blackout on your tank. You'll need to carry out a water change of up to 50%, stick an air stone in the tank if you don't have one and turn of CO2 if you have it and then completely cover the whole tank so no light can enter. Leave it for 3-4 days completely blacked out, your fish and any plants will be fine and then remove the covers, carrying out another water change of up to 50% and cleaning your filter too would be a good idea.
 
You can then remove the air stone and turn any CO2 back on.
 
I don't think this has anything to do with the fish deaths but could be another symptom of an under lying problem. I suggest you check your water stats to see what they are although the blackout and regular water changes should get you back on track. Its just that if you don't know what is causing it you won't know to stop it from happening again in the future. 

 

[phoneticerror]

Thanks for all the responses guys.

My lights are on for around 12-14 hours per day. Put them on before I go to work and turn them off shortly before bed.

It is slimy, yes. My water quality is good, 0 ammonia, 0 nitrite, nitrates are at a reasonable level, and the ph is 7.5.

I'll try to black out method and see if that works. I've not got an airstone because my filter takes care of the aeration too.

Fingers crossed this will get rid of it!

I'll keep you updated on how this goes.

 

[This Old Spouse]

Your lights are on way too long. Aim for 5-6 hours. I've just started only putting mine on in the evening and turning off before bed. Generally too much light and not enough CO2 contributes a lot to algae growth.

 

[DrRob]

Bizarrely, and a good demonstration that BGA isn't really an algae, it likes high organic levels and low nitrates, which are common in underfertilised planted tanks.
 
Blackout is a good idea, water changes are a good idea, and adding some boost to the plants with some macro fertiliser if your nitrates are very low can be quite helpful.
 
edit, and I agree that 12 hours is almost always asking for algae with lighting.

 

[bullit]

I spoke to someone the other day and he said he turns his out at 3 in the morning, he wondered why he had an algae problem lol

 

[phoneticerror]

Now, this is why I don't trust my LFS. "Have a day/night cycle, so make sure that the fish get around 8 hours in the dark per day"

As for the LOL for the guy turning his lights off at 3, how could he possibly know if nobody had warned him? It's not an obvious correlation if you're new to the hobby, and considering we're told that having a good cleanup crew will keep your tank algae free is a touch misleading.

I think I'm on it now, and have adjusted the auto timer for the lights to come on in the evenings for 6 hours per day for when the black out is finished.

Is that definitely what is causing this though? Because I've had the tank running for 3 months and only had this problem for the last 2 weeks. I'm surprised it didn't start much earlier.

 

[DrRob]

Organics building up slowly are often a big part of the culprit.

 

[Lunar Jetman]

I also started to get BGA when I got some plants from a well known UK pet store... It started appearing just after I bought them and when I went back there I could see it on plants in their tanks when I looked!
 
That said, it will only flourish if conditions are right for it to. I now have a powerhead/wavemaker to give the water a bit of churn and I'm reviewing my ferts. I've tried to avoid a blackout but will be doing one on Sunday.

 

[bullit]

To the above. Would the retail store start with pet and end in home without giving it away? , i think mine started aswell thinking about it. Turning the lights out at 3 is a lol, common sense would say you animals need to sleep, though he did say moonlight would be in the wild

 

[Lunar Jetman]

To the above. Would the retail store start with pet and end in home without giving it away?