Dark green algae/diatom bloom on wood

[Fish-mates]

A change from T8's to Led lights plus the addition of an external filter triggered a diatom bloom. I was happy to wait it out till some black beard algae appeared on wood in the tank. I took the wood out, poured hot water on it and gave it a good scrub. The wood's been back in the tank less than a week and already it seems to be covered in a brown diatom dusting. Also, there are new dark green green patches that flake off when touched. Is it cyanobacteria?
Other info: Juwel tank 100 litres with internal and external filters, sand base and moderately planted. The lights are on 3 hours, off 4 hours, on 4 hours. 3ml Seachem Excel per day and 2ml Seachem Flourish twice a week. Water is very hard and Nitrates are frustratingly high. In the past 4 days I've added Rowaphos phosphate remover.

Please have a look at the attached pics as any help would be appreciated.
P.S. the white balls on one of the pics are air bubbles from the diatoms

 

[Munroco]

Cyano bacteria

 

[Fish-mates]

Cyano bacteria

As it's only on the wood do you think I should take the wood out to treat it or should I dose the whole tank?
Also, could the diatoms smothering the wood cause it or is there something else I should be looking at?

 

[Byron]

As it's only on the wood do you think I should take the wood out to treat it or should I dose the whole tank?
Also, could the diatoms smothering the wood cause it or is there something else I should be looking at?

Dose...with what? There is nothing safe (with fish present) to deal with algae or cyanobacteria.

Cyanobacteria is caused by organics in the presence of light. Obviously wood is organic, so what is feeding the cyano is likely from within the wood and perhaps added from the organics in the water, and you are not going to get rid of this without tossing out the wood, which is rather pointless (unless it contains something toxic, another matter). But that brings up another point...never use chemicals or substances other than water on wood. Wood absorbs liquids, and these can remain within for months before they leech out. I once killed fish in a tank from a toxin that leeched out of a chunk of wood that had been purchased at a fish store and in the tank for a year.

Having said all that, from the photos I am not convinced the green is cyanobacteria. Does it readily peel off with your fingertip? If not, it is an algae.

Where are the diatoms in the photo? Does this easily come off with your fingertip?

Byron.

 

[Fish-mates]

Dose...with what? There is nothing safe (with fish present) to deal with algae or cyanobacteria.

Cyanobacteria is caused by organics in the presence of light. Obviously wood is organic, so what is feeding the cyano is likely from within the wood and perhaps added from the organics in the water, and you are not going to get rid of this without tossing out the wood, which is rather pointless (unless it contains something toxic, another matter). But that brings up another point...never use chemicals or substances other than water on wood. Wood absorbs liquids, and these can remain within for months before they leech out. I once killed fish in a tank from a toxin that leeched out of a chunk of wood that had been purchased at a fish store and in the tank for a year.

Having said all that, from the photos I am not convinced the green is cyanobacteria. Does it readily peel off with your fingertip? If not, it is an algae.

Where are the diatoms in the photo? Does this easily come off with your fingertip?

Byron.

Hi Byron

I've read about Ultralife Blue Green Algae Remover from Amazon so thought I'd treat the wood in a large container. No good??

The wood is covered in a dusty browny red coating, which maybe isn't obvious in the pics and was on all the crypt plants, ferns and rocks. It was bad last week, when I took the wood out to scrub it and heavily pruned the plants.

The green definitely comes off easily when touched, yet I thought cyano was bright green and mainly grew on sand or where there's poor flow- and the wood is in the middle of the tank.

I feel confused by this breakout of whatever it is as by putting an additional external filter on I expected flow to increase and the water quality to further improve. Interestingly my rummynose tetras have always look bright nosed and happy whatever seems to grow on plants, wood or rocks around them.

 

[Munroco]

That's what I have used in the past. According to the manufacturer this is safe to use with fish and so far it hasn't caused any losses for me. I'd imagine if it is cyano bacteria that treating the wood separately would be pointless as it is easier just to take the wood out and wipe it off. It's when it grows on plants that its a problem for me.

 

[Byron]

I've read about Ultralife Blue Green Algae Remover from Amazon so thought I'd treat the wood in a large container. No good??

I have already explained how wood absorbs stuff. So that leaves us with what is in this product, and there seems to be a "secret" about this as I cannot find the ingredients anywhere. "Biological ingredients" as someone did mention elsewhere does not mean safe. And it is well known that the most effective "treatment" for cyanobacteria is an antibiotic--cyano is not an algae but a bacteria--and antibiotics are "biological." No aquarist should be adding antibiotics to an aquarium unless the fish have a real health issue for which this is the best treatment. We humans are always being told about the dangers of taking antibiotics needlessly, it is no different here. Fish really must come first, no matter what the issue.

Cyanobacteria can be green, brown/black, or reddish. The green slime is most common in freshwater aquaria, I've battled this a couple times in one tank. It has always first appeared at the surface on floating plants, but I have had it on chunks of wood too. If this is only appearing on the wood, it is likely being fed from the wood, if it is cyano.

As with other types of algae, water flow is not the issue. I have had cyano worst on the spray bar of the canister filter where the water flow is the strongest.

Provided this stays on the wood and does not appear on plants, I personally wouldn't worry too much. As organics feed it and light is involved, keeping the filter and substrate well cleaned and water changes regular and not overfeeding or overstocking are all important.

Byron.

 

[Fish-mates]

I have already explained how wood absorbs stuff. So that leaves us with what is in this product, and there seems to be a "secret" about this as I cannot find the ingredients anywhere. "Biological ingredients" as someone did mention elsewhere does not mean safe. And it is well known that the most effective "treatment" for cyanobacteria is an antibiotic--cyano is not an algae but a bacteria--and antibiotics are "biological." No aquarist should be adding antibiotics to an aquarium unless the fish have a real health issue for which this is the best treatment. We humans are always being told about the dangers of taking antibiotics needlessly, it is no different here. Fish really must come first, no matter what the issue.

Cyanobacteria can be green, brown/black, or reddish. The green slime is most common in freshwater aquaria, I've battled this a couple times in one tank. It has always first appeared at the surface on floating plants, but I have had it on chunks of wood too. If this is only appearing on the wood, it is likely being fed from the wood, if it is cyano.

As with other types of algae, water flow is not the issue. I have had cyano worst on the spray bar of the canister filter where the water flow is the strongest.

Provided this stays on the wood and does not appear on plants, I personally wouldn't worry too much. As organics feed it and light is involved, keeping the filter and substrate well cleaned and water changes regular and not overfeeding or overstocking are all important.

Byron.

Thanks for coming back to me. It is just on the wood - for the moment - and I suppose that's what I'm most worried about as I don't want it to spread or cross contaminate to my other tanks.

Another question is as the wood's been in the tank for 7 months why should it be happening now? And could 30-50% water changes every other day for a week help? What about reducing my lights more?

 

[Byron]

Thanks for coming back to me. It is just on the wood - for the moment - and I suppose that's what I'm most worried about as I don't want it to spread or cross contaminate to my other tanks.

Another question is as the wood's been in the tank for 7 months why should it be happening now? And could 30-50% water changes every other day for a week help? What about reducing my lights more?

I've no idea as to your lighting, and this is certainly an important factor. Algae of course is directly due to lighting and nutrients, whether too much or too little (for both light and nutrients) as algae reproduces faster than higher plants so it readily takes the advantage when the balance is out of whack. Cyanobacteria behaves similarly, since it is fed by organics and is photsynthetic.

You did mention a change from T8 to LED lighting, and I have assumed that this problem has only appeared since the change. I don't know if the LED is more or less intensity than the T8 was. Duration also factors in. If this were me, I would tend to use the plants' response to assess light, intensity and duration. If the plants are thriving, and algae increases, I tend to reduce the duration. I was success in battling brush algae this way, reducing the duration down to 8 hours in 7 tanks, and 7 hours in one tank, at which points the algae disappeared, or more correctly, did not increase which is the goal. But nutrients also play into this; I have had brush algae increase simply from using more fertilizer than needed. Sometimes the balance can be delicate.

Water changes do help control algae, and at the same time they definitely benefit plants (as well as fish of course). But water changes alone will not effectively counter problem algae/cyano because the underlying cause is "stronger" so to speak. The only safe and effective way to deal with problem algae or cyano is to eliminate the cause. Nothing else will really work permanently, or be as safe for the living inhabitants.

I am not sure if the green is cyano or algae. But the approach to deal with either is similar as I've said.

Byron.

 

[Fish-mates]

I've no idea as to your lighting, and this is certainly an important factor. Algae of course is directly due to lighting and nutrients, whether too much or too little (for both light and nutrients) as algae reproduces faster than higher plants so it readily takes the advantage when the balance is out of whack. Cyanobacteria behaves similarly, since it is fed by organics and is photsynthetic.

You did mention a change from T8 to LED lighting, and I have assumed that this problem has only appeared since the change. I don't know if the LED is more or less intensity than the T8 was. Duration also factors in. If this were me, I would tend to use the plants' response to assess light, intensity and duration. If the plants are thriving, and algae increases, I tend to reduce the duration. I was success in battling brush algae this way, reducing the duration down to 8 hours in 7 tanks, and 7 hours in one tank, at which points the algae disappeared, or more correctly, did not increase which is the goal. But nutrients also play into this; I have had brush algae increase simply from using more fertilizer than needed. Sometimes the balance can be delicate.

Water changes do help control algae, and at the same time they definitely benefit plants (as well as fish of course). But water changes alone will not effectively counter problem algae/cyano because the underlying cause is "stronger" so to speak. The only safe and effective way to deal with problem algae or cyano is to eliminate the cause. Nothing else will really work permanently, or be as safe for the living inhabitants.

I am not sure if the green is cyano or algae. But the approach to deal with either is similar as I've said.

Byron.

Many thanks again for taking time to reply.

I've removed the offending piece of wood and done a thorough tank clean today. My plan is frequent pwc, reduced lighting, feeding every other day and less Flourish. Hopefully I can rebalance things and if nothing else, with the wood gone, the fish seem to be enjoying the extra space in the tank

 

[Byron]

Many thanks again for taking time to reply.

I've removed the offending piece of wood and done a thorough tank clean today. My plan is frequent pwc, reduced lighting, feeding every other day and less Flourish. Hopefully I can rebalance things and if nothing else, with the wood gone, the fish seem to be enjoying the extra space in the tank

It is a shame to remove the wood, as that is (or was) a lovely aquascape. I had a similar experience a couple of years ago with a nice piece of branchy wood. It contained some toxic fungus that suddenly appeared and had I not been quick to pull it out and do a major water change, I would have lost all the fish in this 90g tank. After doping what I could to the wood, and trying it again six months later with the same result, white slimy fungus that began affecting the fish, I chucked it.

Another suggestion that should help, is floating plants. These have a dual advantage in any aquarium. First, they obviously help to reduce the light, and as overhead lighting does impact fish this is always a plus. But second, floating plants are nutrient sinks. They can take up more nutrients than lower plants because they have the aerial advantage of easy access to more CO2 in the air, plus the brighter light. You might find that this would be all you need to re-set the balance. Just a thought.

Byron.

 

[Fish-mates]

It is a shame to remove the wood, as that is (or was) a lovely aquascape. I had a similar experience a couple of years ago with a nice piece of branchy wood. It contained some toxic fungus that suddenly appeared and had I not been quick to pull it out and do a major water change, I would have lost all the fish in this 90g tank. After doping what I could to the wood, and trying it again six months later with the same result, white slimy fungus that began affecting the fish, I chucked it.

Another suggestion that should help, is floating plants. These have a dual advantage in any aquarium. First, they obviously help to reduce the light, and as overhead lighting does impact fish this is always a plus. But second, floating plants are nutrient sinks. They can take up more nutrients than lower plants because they have the aerial advantage of easy access to more CO2 in the air, plus the brighter light. You might find that this would be all you need to re-set the balance. Just a thought.

Byron.

I've not totally written off the wood as I'd had it for a good time before this latest problem began. I'm thinking a good scrub, perhaps a black out treatment and my husband suggested blasting it with steam from my steam cleaner.

One question on the idea of floating plants: I've 2 powerheads that create quite a bit of movement on the surface of the water, won't the plants be blown around and all end up in the same corner?

 

[Byron]

I've not totally written off the wood as I'd had it for a good time before this latest problem began. I'm thinking a good scrub, perhaps a black out treatment and my husband suggested blasting it with steam from my steam cleaner.

One question on the idea of floating plants: I've 2 powerheads that create quite a bit of movement on the surface of the water, won't the plants be blown around and all end up in the same corner?

Depending upon the plant species, there are methods around this, or it may not happen. When I write of "floating plants" I am thinking of substantial plants, like Water Sprite (Ceratopteris cornuta, the best floating species of this genus), Water Lettuce (Pistia stratiotes), Frogbit (Limnobium laevigatum) and such. Not the miniature floaters like duckweed. Other good floaters are some of the stem plants, like Brazilian Pennywort (Hydrocotyle leucocephala) which is very effective.

These plants will tend to enlarge, and can often be sort of grouped together. The stem plant can be intertwined at one end around the spraybar or filter tube.

You don't want a lot of surface disturbance as it will drive out CO2. I create disturbance at one end of my larger tanks with the positioning of the spraybar.

Byron.

 

[Fish-mates]

Depending upon the plant species, there are methods around this, or it may not happen. When I write of "floating plants" I am thinking of substantial plants, like Water Sprite (Ceratopteris cornuta, the best floating species of this genus), Water Lettuce (Pistia stratiotes), Frogbit (Limnobium laevigatum) and such. Not the miniature floaters like duckweed. Other good floaters are some of the stem plants, like Brazilian Pennywort (Hydrocotyle leucocephala) which is very effective.

These plants will tend to enlarge, and can often be sort of grouped together. The stem plant can be intertwined at one end around the spraybar or filter tube.

You don't want a lot of surface disturbance as it will drive out CO2. I create disturbance at one end of my larger tanks with the positioning of the spraybar.

Byron.

They look great choices! I'll see what my LFS stocks and give it a go.

Floating plants may also help with the slight film I get on the water's surface. At the moment I direct powerheads to the surface to break up the dusty look on the water and to help oxygenate the water, as I read cyano can come from low oxygen - not that any of my fish have ever gasped at the surface thankfully.

 

[Byron]

They look great choices! I'll see what my LFS stocks and give it a go.

Floating plants may also help with the slight film I get on the water's surface. At the moment I direct powerheads to the surface to break up the dusty look on the water and to help oxygenate the water, as I read cyano can come from low oxygen - not that any of my fish have ever gasped at the surface thankfully.

The film on the surface is most usually a protein film, more common in planted tanks. It is, again, related to organics. Over my 20+ years, I have had it only in a very few tanks, never in the others. I used to use the surface skimmer attachment for canister filters (I had Eheim) but aside from plant bits getting pulled in and clogging it, very small fish also got sucked in and they usually couldn't be rescued; otos were fond of getting themselves stuck. So I took off the skimmers.

The protein film is most likely to appear along with cyanobacteria or algae problems, which makes sense since they are all caused by the same thing, organics. Low oxygen will cause problems but not directly cyano. I have increased the surface disturbance just a tad to increase oxygen which I believe was minimal in the early morning after a night of CO2 building up naturally. I had no algae or cyano issues, but the increased surfacing of the corys alerted me to this, and the increased surface disturbance solved it. It doesn't take much, just some, and this was most likely due to the heavy planting in this tank. My smaller tanks, 40g and under, all have simple sponge filters and they have no issues with oxygen, CO2, algae, cyano...whatever.

So back to the film, I now see it some weeks but only in my 90g which has an organics issue that I cannot track down. I deal with the film by turning the water changing unit upside down under water and pulling in the surface water. Takes a bit of time, but it does work. I tried the paper towel on the surface method and it was a real mess and ineffective anyway.