# Question about Seachem Excel



## burr740 (Feb 19, 2014)

1. My fish do the same thing. I just pour the Excel straight in near a filter output and dont worry about it.

2. Not that Im aware of. I've dosed 2-2.5x daily amounts on several different tanks and never seen a negative effect on livestock. (talking about fish, not sure about shrimp)

3. Obviously you should avoid direct contact, but I dont think it's a problem otherwise. Granted I have no science to back that up.

4. No

5. No


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## adive (Oct 30, 2013)

burr740 said:


> 2. Not that Im aware of. I've dosed 2-2.5x daily amounts on several different tanks and never seen a negative effect on livestock. (talking about fish, not sure about shrimp)


Will Excel not harm my upside down catfish? I dont know for sure but isnt it scaleless and thats why my question.





burr740 said:


> 3. Obviously you should avoid direct contact, but I dont think it's a problem otherwise. Granted I have no science to back that up.


As part of regular maintenance we do insert our hands into the water, into which we have injected/poured Excel. You are saying thats ok, as its so diluted?

Thanks.


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## burr740 (Feb 19, 2014)

adive said:


> Will Excel not harm my upside down catfish? I dont know for sure but isnt it scaleless and thats why my question.


Never had one of those fish so I really cant say. My guess is it would be fine.



adive said:


> As part of regular maintenance we do insert our hands into the water, into which we have injected/poured Excel. You are saying thats ok, as its so diluted?


That would be my opinion - which doesnt mean much if you're looking for concrete evidence one way or the other. Personally I dont worry about it.


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## Raymond S. (Dec 29, 2012)

+1 for Burr740
I do not follow the directions for after adding water/water changes. I use 2 ml per
10g tank which is 2x the recommended doses(aprx. it says 5 ml per 50g) each day
and after the water change I add the same thing.
It breaks down after a couple of hrs into carbon so I really don't know if it would hurt
you before that but if there are fish/shrimp IN it then I don't think it would amount to all that. It did make my RCS react hyper when I changed from 1 ml to 2 ml but after a couple of days of it they haven't since.
Disposable plastic Pipettes are on e-bay for cheap as are syringes to dose/w.


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## mattinmd (Aug 16, 2014)

+1 for Burr740, except that:

5. Only in extreme concentration. This stuff is a surgical disinfectant when used in concentrations (2.6%) higher than the seachem bottle contains (2%), so if you soak your biomedia in undiluted excel it most definitely will kill your beneficial bacteria. At the concentrations applied in-tank (~1ppm), it i's no risk to beneficial bacteria.


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## TLE041 (Jan 16, 2010)

Glutaraldehyde, the active ingredient in Excel, can actually cause chemical burns to tissues and things like blindness when it gets splashed into the eyes (I'm in the medical field and use it at work). As a precaution, I avoid using it directly in the tank in case a fish swims right into it and always add it to my water change bucket or a small cup of water.


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## Solcielo lawrencia (Dec 30, 2013)

Glutaraldehyde may not actually provide any carbon that plants can use:
http://www.barrreport.com/forum/bar.../225938-glutaraldehyde-is-not-a-carbon-source

It may just be killing the periphyton (most likely since it's a biocide) which means the plants are able to access the limited amounts of CO2.


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## mattinmd (Aug 16, 2014)

Solcielo lawrencia said:


> Glutaraldehyde may not actually provide any carbon that plants can use:
> http://www.barrreport.com/forum/bar.../225938-glutaraldehyde-is-not-a-carbon-source
> 
> It may just be killing the periphyton (most likely since it's a biocide) which means the plants are able to access the limited amounts of CO2.



Hmm, I read that thread as fairly solidly proving that Glutaraldehyde does provide carbon that plants can use, through aerobic breakdown to CO2.

That said, Tom does correctly point out that it is a fairly trivial amount of CO2 compared to CO2 injection.. 



> Some CO2 is used certainly by the plants, but there's just not enough to make a large dent in growth.


This does lead to the conclusion that the carbon provided by glut is not significant enough to provide algae suppression, and that part probably comes from the biocide activity.

But to say that it isn't a carbon source for plants at all? That's provably incorrect.


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## adive (Oct 30, 2013)

TLE041 said:


> Glutaraldehyde, the active ingredient in Excel, can actually cause chemical burns to tissues and things like blindness when it gets splashed into the eyes (I'm in the medical field and use it at work). As a precaution, I avoid using it directly in the tank in case a fish swims right into it and always add it to my water change bucket or a small cup of water.


Just trying to understand what you are trying to say. Are you trying to say even fish tissue and their eyes could get damaged over a period of time and therefore excel is not a good thing for your tank? But I see that you are also using it in your 12g.

I've seen some cool tank journals on here use excel & glut over a long period of time successfully, fish growing and spawning - see wkndracer


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## Solcielo lawrencia (Dec 30, 2013)

mattinmd said:


> Hmm, I read that thread as fairly solidly proving that Glutaraldehyde does provide carbon that plants can use, through aerobic breakdown to CO2.
> 
> That said, Tom does correctly point out that it is a fairly trivial amount of CO2 compared to CO2 injection..
> 
> ...


At some point, the biocidal effects surpass whatever benefits it provides; i.e. it begins to damage/kill plant tissue. Also, if it were true that more glut = more CO2, then there should be a proportionate increase of growth. But there isn't. Further, if there is more CO2, then there should be more O2 from photosynthesis. But there isn't. This is further evidence that glut doesn't provide CO2. Lastly, those who used both CO2 and glut simultaneously have reported improved growth with CO2 alone. Why is that?


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## Hoppy (Dec 24, 2005)

Excel isn't CO2, and doesn't become CO2. It is an organic compound that plants can use to get more carbon than they would have from just the atmospheric CO2 dissolved in the water. Way too many people have seen the improved plant growth from using it to ever convince me that it is not beneficial to the plants. It isn't a good enough source of carbon to meet the plant's needs with high light, but that doesn't mean it isn't of great benefit with low to medium light. I have never seen any problems with my fish from using it at 2 ml per 10 gallons of water. And, I now use Metricide at the same dosage, which is equivalent to even more Excel per 10 gallons -still no problems. Seachem recommends 5 ml per 10 gallons as a "starter" dose, so obviously they found no problems at that dosage.


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## Solcielo lawrencia (Dec 30, 2013)

Hoppy said:


> Excel isn't CO2, and doesn't become CO2.


Glutaraldehyde does indeed break down into CO2. The amount is trivial, however.



> It is an organic compound that plants can use to get more carbon ...


This is an unproven assumption. There have been no experiment to understand the mechanism of action in plants.


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## TLE041 (Jan 16, 2010)

adive said:


> Just trying to understand what you are trying to say. Are you trying to say even fish tissue and their eyes could get damaged over a period of time and therefore excel is not a good thing for your tank? But I see that you are also using it in your 12g.


Read my post again.

I'm saying that using it directly on living tissues can cause chemical burns, so I avoid using it directly into the water in case once of the livestock swims right into the Excel cloud. This isn't an issue once it's dispersed into the water column. There's also no issue with long-term harm because Glutaraldehyde has a very short lifespan once added to the tank (~24 hours IIRC).


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## mattinmd (Aug 16, 2014)

Solcielo lawrencia said:


> At some point, the biocidal effects surpass whatever benefits it provides; i.e. it begins to damage/kill plant tissue. Also, if it were true that more glut = more CO2, then there should be a proportionate increase of growth. But there isn't.


References? I've not seen any studies demonstrating the lack of increased O2 or plant mass as a result of glut supplementation. I'd like to see the numbers there, including how many ppm of glutaraldehyde is being used in the test.

edit:
Actually, thinking about it, the O2 shouldn't show an increase.. Glut provides carbon, which becomes CO2 through aerobic breakdown, but that consumes oxygen. Later, if a plant were to use that CO2 molecule and produce O2, it would just be replenishing what is depleted. Thus, the best glut can do is be oxygen-neutral... If it were unused by plants it would be reducing overall O2 output.



Solcielo lawrencia said:


> Lastly, those who used both CO2 and glut simultaneously have reported improved growth with CO2 alone. Why is that?


This one makes entire sense to me... If you're already providing enough CO2 to be non-limiting to plant growth, adding glutaraldehyde isn't going to provide more carbon to plants. Thus, the only possible effect is the biocidal one... 

This is taking your biocidal-vs-carbon argument to the extreme, where growth wise glut can only provide drawbacks and no benefits. It does at least prove that the biocidal action has negative impacts on plants at some concentration.


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## burr740 (Feb 19, 2014)

Hoppy said:


> .... Way too many people have seen the improved plant growth from using it to ever convince me that it is not beneficial to the plants. It isn't a good enough source of carbon to meet the plant's needs with high light, but that doesn't mean it isn't of great benefit with low to medium light. I have never seen any problems with my fish from using it at 2 ml per 10 gallons of water. And, I now use Metricide at the same dosage, which is equivalent to even more Excel per 10 gallons -still no problems. Seachem recommends 5 ml per 10 gallons as a "starter" dose, so obviously they found no problems at that dosage.


Count me in as one of those people. I also use that exact same dose of Metricide.

These threads always spark a spirited debate what it actually does and whether it helps plants or not. And while the exact science can be argued all day long, the best proof will come from personal experience.


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## adive (Oct 30, 2013)

TLE041 said:


> Read my post again.
> 
> I'm saying that using it directly on living tissues can cause chemical burns, so I avoid using it directly into the water in case once of the livestock swims right into the Excel cloud. This isn't an issue once it's dispersed into the water column. There's also no issue with long-term harm because Glutaraldehyde has a very short lifespan once added to the tank (~24 hours IIRC).


I see, great. The crucial point is to dose it correctly and thats exactly been one of my questions in the OP and you say you add Excel to the WC bucket water and then add that water into the tank so the Excel is diluted so much that it cant form a concentrated cloud in the tank. Good, I will use that or a similar technique.

Thanks.


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## Hoppy (Dec 24, 2005)

I think you will find that most of us just dump in the Excel dosage and have no problems from doing so. The glutaraldehyde in Excel is very dilute to start with, and becomes even more dilute almost instantly when poured into the tank water. It is dangerous at high concentrations, but apparently not at the low concentrations we use.


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## adive (Oct 30, 2013)

Hoppy said:


> I think you will find that most of us just dump in the Excel dosage and have no problems from doing so. The glutaraldehyde in Excel is very dilute to start with, and becomes even more dilute almost instantly when poured into the tank water. It is dangerous at high concentrations, but apparently not at the low concentrations we use.


Cool, thanks, exactly what I was looking for.


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## mattinmd (Aug 16, 2014)

Hoppy said:


> I think you will find that most of us just dump in the Excel dosage and have no problems from doing so.


Yep, I just dump it in, although I try to dump it in right in front of the filter outflow. This makes it dillute faster, but also gets it spread around to where the plants faster too.

The exception is when I use it as a spot treatment.


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## adive (Oct 30, 2013)

mattinmd said:


> Yep, I just dump it in, although I try to dump it in right in front of the filter outflow. This makes it dillute faster, but also gets it spread around to where the plants faster too.
> 
> The exception is when I use it as a spot treatment.


Yup


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## Soxfandowd (Aug 1, 2014)

I too dump it in right in front of the filter outflow. I put it in 1 hour before the lights come on because I read somewhere that this was better?? Anyhoo the added bonus of that is that I don't have the fish coming up to the top to see what I am doing as they are still sleeping. I do this with my dry ferts too.


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