What's this?

[crystalite]

I bought a floating ball of java moss in my LFS and it got covered in algae quite quickly when I had it in my 28 litre tank. I wasn't concerned as I want to add some algae eaters to my tank so I just left it. I've moved the ball to my new 125 litre tank now and the ball has just turned to a gross blob. I think it looked like long thick strands of algae before that were quite tough but pulled off easily now it looks like a very dense web of bluish green and the java moss is unrecognisable. I've tried to add a picture but haven't done one on here before so it may not work. What I'd like to know is what type of algae is it? Is it safe to leave in the tank or will it harm my fish, plants etc? Would an algae eater such as otocinclus, cherry shrimp eat it? Should I leave it in, try to remove the algae or do I need to throw the whole ball out and cut my losses?

[madagascariensis]

that moss ball is covered in blue green algae, which
can sometimes secrete chemicals harmful to animal life.

It is not really an alga but a type of anaerobic bacteria that protects itself against oxygen with a
mucus covering.
Unfortunately, no algae eater will eat it and you should remove it as soon as possible before more of your tank gets infested.

[crystalite]

Thanks for replying. I took the moss ball out as soon as I read your post and I had to remove a sickly looking bit of plant that had the same stuff on aswell. I've had a good look around and can't find any more so hopefully I got it all. Is there anything else I need to do to make sure it doesn't come back? Should I be worried about my fish or will they be okay now it's out?

[madagascariensis]

As long as there aren't huge amounts of it in the tank, I would not worry about the fish.
Increasing the amount of water changed per week and decreasing food has worked for me, along with rubbing it off the plants and sucking it up with a vacuum. If you don't remove it after rubbing it off a surface the algae bits will re-settle and grow wherever they land.

[Cliff]

It looks like what you had was Cyanobacteria

[crystalite]

I think I got it all off but it's hard to tell as there's loads of algae in the tank (I'm collecting it for my ottos that I've just added ). I'm not sure if some of the stuff in there is knotts of hair algae or the bad stuff. I thought I found some on a plant so I ripped off the leaf and threw it in a jar off bladder snails I'd took out of the tank thinking if it was anything bad the snails would climb out of the water or die off but they devoured it within minutes leaving a nice clean healthy leaf. I was a little annoyed as I'd shredded my plant and wasted potential otocinclus food. I'm getting obsessed that everything not perfectly green in the tank is this stuff and some of the things I've read online about it make me worry all my fish are going to get poisoned if I don't compulsively check the tank for it . Although so far everyone seems happy and healthy.