I recently found this really odd "plant" in our 20g tank. It is stringy, black/green, and grows on our aquatic plants. I moved it to our "snail tank" so we can observe it. Any ideas on what this is? It reminds me of mold, and grows pretty fast.

EDIT: oops I just noticed this should be under "what's this plant?"
{no problem, we can fix that - Kana}

Identifying something like this without a pic is hopeless.

I doubt it's a mould, or fungus. I'd say an Algae, on probabilities.

What is it, that makes you think 'Plant'? Does it 'branch'?


PS - Welcome back Fisher!

I say, without seeing it, that its algae.

sounds a bit like blue green algae (Cyanobacteria)
to me. if it is, the best way to get rid of it i recon is to up ur water maintenance and do a 3-4 day black out on the tank followed by a 25-50% water change.

it is a bum to get rid of totaly as it can come back at anytime, but if u up the water changes it should help. assuming it is the dreaded BG of course.

I have a real Love / Hate thing with these sort of posts.

I Love the 'Detective' element, getting all the clues, asking the questions, colating the data.

But it shit's me no end, when they leave you dangling, should they ever return. (not directed at you Fisher, ok?)

LOL well, I can't get a pic 'cuz its in a really dark tank full of snails and their droppings...when I picked it up it reminded me of a tough fiber, kinda like....acrylic or even wool. Sorry I can't get too detailed... I really don't know much about it.

without a picture we are probing in the dark so to speak but by the description as fishpaw has already said it does indeed sound like blue green algae (cyanophyta) which of all the algae is the most primitive & is capable of producing toxins that are poisonous to fish so if it is blue green algae you need to eradicate it from your tank before it becomes a problem (if you have not introduced this as a plant then it is very likely an algae) what you need to do is remove a much of the offending algae as possible including if possible all rocks,wood,decorations and plants use hot water and somthing like a toothbrush/nailbrush if you cant get them clean that way try boiling them and start doing water change
you should also look into the reason for the problem such as is there too much light or not enough light i.e what type of lighting are you using how long are the lights on is the tank hit by natural light
whats your water quality like how much water do you change and how often do you do a water change
is it just an algae bloom how long have you had it in your tank?

One possibility is to stick your hand in, and place some where you can get a good shot...

Does it look like this?

Only registered users can see links on this forum! Register or Login on forum!

My grandma had something similar in her tank. It's really tough and it spreads all over the plants. Not many fish seem to eat it either.

Excellant link, Bones.

I'm not one for stressing over Algae. And have a fair portion of in my tanks.