Cyanobacteria? Dark/blueish green stuff

targetfish

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I've tried to get rid of it but it keeps coming back. What is it, is it harmful, and how can I get it to go away?
 

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Looks like Cyanobacteria. A very good remedy I can vouch for is called Ultra Life Blue Green Slime Stain Remover.

Sounds like it’s for cleaning a sink but it’s extremely effective - does just what it claims to do and is not based on an antibiotic like a competing product called Chemiclean, which is based on erythromycin despite a misleading label that suggests it isn’t an antibiotic.

Erythromycin might wipe out a biofilter - Ultra Life won’t harm nitrifiers. Plus, using an antibiotic for something like this is a really poor idea, environmentally speaking.

Cyanobacteria aren’t necessarily harmful though some can be toxic - but it can easily cover every surface left to its own devices and II often has an unpleasant odour - if a lot of it grows, you’ll smell it. The odour is distinctive - but not as bad as a decomposing snail, for example.

The lighting might be too intense or on a bit too long so you should try adjusting that once it’s cleared up.

It can show up for a few reasons or combinations of them other than lighting - low water flow, excessive nutrient levels in the water (especially nitrogen & phosphates) or excess organic wastes in or on the substrate or dead spots where grunge accumulates because there isn’t any circulation in that spot.

Try increasing the water flow, adding floating plants that suck up lots of nutrients & keeping the substrate free of accumulations of wastes.,
 

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Are we seeing a recently set up newer tank going through growing pains?

If so Fishfur hit it on the nailhead. Judging by apparent signs of random algae on glass I’ll take insufficient circulation and/or water flow patterns around tank for $500 Alex.
 
The only times I've ever experienced Cyanobacteria is when the lights were set too bright & left on too long.

The times I dealt with the blue green goo, manually removing it & dimming the lights did the trick.
 
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  • #5
Are we seeing a recently set up newer tank going through growing pains?

If so Fishfur hit it on the nailhead. Judging by apparent signs of random algae on glass I’ll take insufficient circulation and/or water flow patterns around tank for $500 Alex.
Well, it's actually been running for over a year.
You're probably right though, since the filter is very low flow.

Looks like Cyanobacteria. A very good remedy I can vouch for is called Ultra Life Blue Green Slime Stain Remover.

Sounds like it’s for cleaning a sink but it’s extremely effective - does just what it claims to do and is not based on an antibiotic like a competing product called Chemiclean, which is based on erythromycin despite a misleading label that suggests it isn’t an antibiotic.

Erythromycin might wipe out a biofilter - Ultra Life won’t harm nitrifiers. Plus, using an antibiotic for something like this is a really poor idea, environmentally speaking.

Cyanobacteria aren’t necessarily harmful though some can be toxic - but it can easily cover every surface left to its own devices and II often has an unpleasant odour - if a lot of it grows, you’ll smell it. The odour is distinctive - but not as bad as a decomposing snail, for example.

The lighting might be too intense or on a bit too long so you should try adjusting that once it’s cleared up.

It can show up for a few reasons or combinations of them other than lighting - low water flow, excessive nutrient levels in the water (especially nitrogen & phosphates) or excess organic wastes in or on the substrate or dead spots where grunge accumulates because there isn’t any circulation in that spot.

Try increasing the water flow, adding floating plants that suck up lots of nutrients & keeping the substrate free of accumulations of wastes.,
Thank you so much for this, Fishfur! Really makes sense, and I appreciate you explaining it in such depth. :)

I've ordered Ultra Life; sounds like it might work well. It’s also good to know it won’t mess with BB like antibiotics do.

I hadn’t really thought much about how much lighting, flow, nutrient levels and substrate maintenance can affect cyanobacteria, so that part of your advice is also super useful. Gives me much a better idea of what to adjust.
 
I agree with everything fishfur said, but the part about nutrients is not straight forward. Cyanobacteria.can occur when there is a lot of decaying material present, but it usually tends to appear when nitrates are very low, and/or the ratio of phosphates to nitrates is high.

I have also used the ultra life stuff, it definitely works well. Its best to remove as much as possible manually first. Reducing the hours or intensity of light will definitely help as well.
 
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  • #7
I agree with everything fishfur said, but the part about nutrients is not straight forward. Cyanobacteria.can occur when there is a lot of decaying material present, but it usually tends to appear when nitrates are very low, and/or the ratio of phosphates to nitrates is high.

I have also used the ultra life stuff, it definitely works well. Its best to remove as much as possible manually first. Reducing the hours or intensity of light will definitely help as well.
Ohh, that makes even more sense now! This tank is the only one I don't use fertilizers for, because the plants seemed to be doing just fine. It's also my least planted tank. I did reckon my nitrates were very low. None of my other tanks have this issue and they're even newer and the lighting is exactly the same. Still, I'll definitely be adjusting the other aspects.
 
Well, it's actually been running for over a year.
You're probably right though, since the filter is very low flow.
One of the main circulation concepts that is overlooked by many is the need for a current that moves water high to low, not just circling around tank left<>right etc.

Take this little sponge filter as a perfect example.

https://a.co/d/avhOYrB

Not high flow by any means, especially after it gets a little detritus built up on sponge. But drop that sponge in back right corner and then swing that spray bar around all the way to left so it’s in center’ish of back wall , point it down and slightly aimed towards back glass so it makes a sweep of water down that back glass wall behind plants that will push out detritus back there as well as push micro currents into substrate layer.

Seriously, make a simple change like this and within a month I’m pretty sure you will notice the difference. One low flow filter doing left<>right circulations around tank, another doing the high/low water exchange.

PS: I’ve got one of those hygger filters in a 5g quarantine bucket, very good filtration and output options for the $$$.
 

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