# GDA, how to get rid of it



## plantbrain (30 Sep 2011)

There have been a few methods suggested, but for the more longer term persistent GDA blooms, Erythromycin has shown to work and prevent  re-occurrence in at least 10 long term aquarist 's tanks that had long bouts with Green Dust Algae. So far several have not had any re occurrences. 

We do not quite know why it works, only that is does seem to be pretty good at clearing up the tougher cases.
Some have speculated it's a BGA/GDA relationship.

That is still quite unknown........and we still do not know what induces GDA, which is one of the keys to addressing algae over the long term and prevention.


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## clonitza (1 Oct 2011)

As far as I've noticed in my tanks after cleaning the glass some biofilm is forming and a couple of days later GDA starts growing on it. If I remove the biofilm the GDA doesn't appear, same thing with stones etc.

Mike


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## Radik (1 Oct 2011)

So using antibiotics for GDA? What dosage? Shrimp and fish safe?


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## Ian Holdich (1 Oct 2011)

it's a bit OTT for GDA removal IMO. I work with antibiotics everyday and everyday something new becomes resistant, here's another for you. 

I know that over here in the UK you will struggle to get a prescription for Erythromycin for an algae outbreak. Luckily vets are now taking things like MRSA seriously, so won't dish ABX out willy nilly. 

wasn't it you Tom that said the best way to overcome GDA you'd be best to leave it for a few weeks and then it'll run it's lifecycle?


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## plantbrain (1 Oct 2011)

ianho said:
			
		

> it's a bit OTT for GDA removal IMO. I work with antibiotics everyday and everyday something new becomes resistant, here's another for you.
> 
> I know that over here in the UK you will struggle to get a prescription for Erythromycin for an algae outbreak. Luckily vets are now taking things like MRSA seriously, so won't dish ABX out willy nilly.
> 
> wasn't it you Tom that said the best way to overcome GDA you'd be best to leave it for a few weeks and then it'll run it's lifecycle?



I agree with the statement above 110%.

But in some serious cases, the EM works well.

I really have no issues with this alga, but......I've tested this on several folks that have had GDA for months on end........nothing worked except this. So I tried it on a few other folks to be sure........same thing.

Still waiting for post treatment results, this takes 2-4 weeks at least, but everyone has been free and clear thus far. 
EM used rarely for a plant tank poses virtually no risk, whereas adding it to the food supply like they do in the USA, poor human dosing(many patients do not take the full dosage or stop). This is a numbers game and there's just not many no#'s in this hobby to cause much impact. The bacteria/cyano bacteria seems to.may have some link to the GDA persistence. These bacteria are not infectious disease bacteria.

I'd try the other methods first, then use this as a last resort personally.

We still do not know what induces GDA to begin with, that's the key in my view.


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## plantbrain (1 Oct 2011)

Radik said:
			
		

> So using antibiotics for GDA? What dosage? Shrimp and fish safe?



EM is safe for filters and fish, shrimp etc.


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## tyrophagus (1 Oct 2011)

I work with antibiotics. My colleagues and I get the blame when diseases become resistant to antibiotics. Hobbyists treating their tanks to clear algae is the type of reason why they remain on prescription in the uk. Most people don't understand the ramifications of inappropriate use. 

So where does all this water end up containing the antibiotics. In the sewer and then the local river or groundwater. 

In humans the erythromycin estolate salt has been implicated in causing cholestatic hepatitis. Probably not a problem if your arm gets wet with antibiotic water but hey it's your call. 

I know that there are industries that abuse antibiotics in vast quantities, primarily making meat for us to eat. Just because others abuse antibiotics does NOT make it ok for us to do the same.


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## plantbrain (2 Oct 2011)

*Re:*



			
				tyrophagus said:
			
		

> I work with antibiotics. My colleagues and I get the blame when diseases become resistant to antibiotics. Hobbyists treating their tanks to clear algae is the type of reason why they remain on prescription in the uk. Most people don't understand the ramifications of inappropriate use.



As a Biologist, I know the run down there, we address this in Microbiology class and I make a big deal over infectious diseases every year.

AIDS and waiting till we have a super cocktail so the damn thing does not gain resistance.........but save a few and extend lives a little bit today, or cure it 4 years from now?

Tough choice.

I have a nice exam question, "Name all the ways to make antibiotics ineffective?"

There are about 13 or so different answers, in the USA, we do all 13  
They get credit for 6 or more right answers.



> So where does all this water end up containing the antibiotics. In the sewer and then the local river or groundwater.



Well, environmental fate is always interesting, but bacteria can still break down most anything IME. EM does not last forever.

Endocrine disruptors are a lot more of interest to me and wreck a lot more havoc on aquatic ecosystems. These are far intense for small amounts added. EM etc, all these anti biotics heading into open systems loaded with.......what? Bacteria, they come into contact with. Does the EM just a keep on going and on on and on?

No........it's not going to do that, it will bond with substrates and get broken down.
Same with ED's, but not nearly as fast and they target higher trophic levels specifically.



> In humans the erythromycin estolate salt has been implicated in causing cholestatic hepatitis. Probably not a problem if your arm gets wet with antibiotic water but hey it's your call.
> 
> I know that there are industries that abuse antibiotics in vast quantities, primarily making meat for us to eat. Just because others abuse antibiotics does NOT make it ok for us to do the same.



This is about risk, pure and simple. So what are the risk might I inquire?
What are the risk involved if 50-200 aquarist a year use this?

Give me some numbers.

In the large scale of things, simply me not suggesting a GFI circuit breaker would be irresponsible as well, that could be a made a rallying point if you want to discuss risk to the hobbyists and by this method I suggest, I am pragmatic about this, not draconian. Or the suggestion to do a water change, wastes water after all.........but we all do this type of stuff daily.

I prefer to know why the alga grows to begin with, then prevention works far better and requires no "cure". Some folks have not been able to fix the GDA any other way. This is a management tool for them. folks ALREADY do this for BGA, and I've long made the argument ot do a blackout + KNO3 dosing......but that method works.........GDA is much more pesky for many........BGA, unlike GDA, is something we can induce and know generally why it blooms in out aquariums. Until someone figures out why GDA blooms in the planted tank, we have limited tools and approaches.
Since we do not know what induced GDA, we lack the knowledge base to approach it that way.

As I stated initially, I do not have any issues with GDA, but I realize many folks hate it and cannot get rid of it for whatever unknown reason.

If you wanna carry that banner, bully for you, but I'm just not that hardcore about it, there are larger management issues there that are far more threatening(food supply, usage by patients). We could say there's a threat by our simply keeping aquarium fish that poses to the environment, and exposure to Hep C since the rational" Every little bit you can do to help" applies, why not just have no one keep plants or fish in the hobby??? 

Same with keeping these aquatic weeds, which hobbyist spread and often ends up in natural ecosystems.
there's a risk there too. I deal with that risk professionally. 

We are more pragmatic and rationalize things a bit more, accept some risk........otherwise none of us would even be here discussing fish, plants etc...........













This poses a tiny tiny risk.


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## tyrophagus (2 Oct 2011)

The risks are small and there are more damaging and dangerous practices out there. I agree. 

I suppose my problem is the promotion of antibiotic use for aesthetic purposes in a fish tank. I treat infectious disease, sometimes antibiotics save lives, I don't want them misused by anyone even a handfull of aquarists.


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## Mark Evans (2 Oct 2011)

tyrophagus said:
			
		

> I suppose my problem is the promotion of antibiotic use for aesthetic purposes in a fish tank. I treat infectious disease, sometimes antibiotics save lives, I don't want them misused by anyone even a handfull of aquarists.



here, here. I completely agree.

How about good housekeeping to keep GDA at bay?   

I rarely suffer it nowadays.


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## Aquadream (2 Oct 2011)

I suppose some will decide in case of unbeatable algae bloom to just re make the whole tank. Others however will decide that it was too expensive to get it done and re make would not be as good idea as the use of some small treatment such as antibiotics.
Good house keeping is probably the best idea, but providing the fact that we all use ready made substrates and many other ready made products who can really foresee what the definite outcome is going to be.
Algae bloom can happen to all even to the very experienced.
So I would allow just any outcome if it fits the purpose and it does not lead to the end of the world.


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