What is this?

[WhistlingBadger]

I've got this weird, brilliant blue-green growth on one of the wood bits in my river tank. It is only on this one piece of wood, none of the others. It looks like someone painted it. I don't really mind it too much, but if it's cyano or something that will spread, I should probably remove it and sanitize the piece. What says the Fish Forum Oracle?

 

[Slaphppy7]

I've had that on DW before in the past, as well...it eventually faded away...no clue what it is, though

Next time you do a WC, see if it will rub or scrape off, if it bothers you...

 

[Back in the fold]

I think you identified it correctly . Weird .

 

[WhistlingBadger]

Thanks, guys. I originally left it because I want some biofilm in this tank for the hillstream loaches. But they don't touch this, which makes me suspect it's BGA. The branch it's on is intertwined with the others, so I don't want to take it out if I can help it.

 

[CaptainBarnicles]

It does look like cyanobacteria like all good problem solvers, you're going to have to take a sample and investigate...the scratch and sniff test works well

 

[Uberhoust]

Looks like cyanobacteria to me.

 

[Sgooosh]

I've got this weird, brilliant blue-green growth on one of the wood bits in my river tank. It is only on this one piece of wood, none of the others. It looks like someone painted it. I don't really mind it too much, but if it's cyano or something that will spread, I should probably remove it and sanitize the piece. What says the Fish Forum Oracle?

View attachment 330211

if it is cyanobacteria, personally I would pressure hose it off, since too much of it can be harmful to fish i think.
also because it can make the tank smell bad if left to grow a lot

 

[CaptainBarnicles]

if it is cyanobacteria, personally I would pressure hose it off, since too much of it can be harmful to fish i think.
also because it can make the tank smell bad if left to grow a lot

Yup, it stinks

 

[Back in the fold]

Thanks, guys. I originally left it because I want some biofilm in this tank for the hillstream loaches. But they don't touch this, which makes me suspect it's BGA. The branch it's on is intertwined with the others, so I don't want to take it out if I can help it.

This is why you always boil driftwood before use . You don’t know where it’s been .

 

[WhistlingBadger]

So, I took the piece out for a closer look. I don't think it's cyanobacteria/BGA. It just smells like aquarium, and it doesn't come off in nasty sheets. It's more like it's embedded into the surface of the wood. I couldn't even scrub it off with a scrub brush. I sprayed it generously with hydrogen peroxide, let that soak in for a half hour or so, rinsed it under very hot water, and put it back in. Other than being possibly a bit lighter in color, there is no change. Very strange.

 

[GaryE]

I see it all the time. It's Cyano. It may decide to spread, or not. You can go at it with a brush. it always comes back, but you can control it.

There have been pieces of wood that ended up[ in the garden because of it - it seems to find nutrients to its liking on some pieces, but not others. I had some wood from a peat bog that never got it, but wood I've soaked and sunk myself is more vulnerable to it.

 

[WhistlingBadger]

I don't understand why the peroxide didn't kill it. Tough stuff, I guess. I'll probably just remove that piece. I need to keep lighting high so the loaches have biofilm to eat, and I don't want it spreading.