# Excel toxicity (Not to plants)



## clownplanted (Mar 3, 2017)

So in a sense isn't metricide the same thing but just more concentrated? So by using less be really the same thing?


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## sohankpatel (Jul 10, 2015)

clownplanted said:


> So in a sense isn't metricide the same thing but just more concentrated? So by using less be really the same thing?
> 
> 
> Sent from my iPhone using Tapatalk


It is more concentrated, but from what I have read and heard, excel is farther along the path to being usable to plants. 
Glutaraldehyde needs to be broken down to be used by plants, excel is farther along the path to being broken down from my understanding.


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## clownplanted (Mar 3, 2017)

sohankpatel said:


> It is more concentrated, but from what I have read and heard, excel is farther along the path to being usable to plants.
> 
> Glutaraldehyde needs to be broken down to be used by plants, excel is farther along the path to being broken down from my understanding.




Got it. Was thinking about using metricide to save in costs but now this has me second guessing. I have not used metricide yet but only excel. I really like the excel and my plants seem to. Just wonder the actual testing that went along with developing it in regards to fish and inverts. You do bring up good points. 


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## Seattle_Aquarist (Jun 15, 2008)

Hi sohankpatel,

All I know is a mass spectrometer analysis of Seachem Flourish Excel confirmed that Excel contains 1.5% Glutaraldehyde; *here is a link to the thread at indianaquariumhobbyist.com* where the test results are cited (see post by arupch dated April 12th, 2006 @ 9:09pm). Tom Barr in his talks at our club stated that Excel is Glutaraldehyde. I don't know what else to tell you.

Now, is Excel/Glutaraldehyde toxic - yes. Is it as effective as using CO2 gas as a source of carbon for plant growth - no. Is it better than nothing at all - yes. As with all things in life we have to make our own choices and live with the consequences.


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## sohankpatel (Jul 10, 2015)

Seattle_Aquarist said:


> Hi sohankpatel,
> 
> All I know is a mass spectrometer analysis of Seachem Flourish Excel confirmed that Excel contains 1.5% Glutaraldehyde; *here is a link to the thread at indianaquariumhobbyist.com* where the test results are cited (see post by arupch dated April 12th, 2006 @ 9:09pm). Tom Barr in his talks at our club stated that Excel is Glutaraldehyde. I don't know what else to tell you.
> 
> Now, is Excel/Glutaraldehyde toxic - yes. Is it as effective as using CO2 gas as a source of carbon for plant growth - no. Is it better than nothing at all - yes. As with all things in life we have to make our own choices and live with the consequences.


I never said that it wasn't glutaraldehyde, just that it is broken down slightly more thand raw glut. I am just repeating what I have been told by a scientist that I trust knows what he is doing.


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## Seattle_Aquarist (Jun 15, 2008)

Hi sohankpatel,

The current Seachem page has the 2016 MSDS sheet with isn't much help - just 'proprietary' mumbo jumbo. *The 2008 version of the Seachem Excel MSDS sheet* listed the product as containing "Aqueous solution of glutaraldehyde"; here is what a seemingly knowledgeable poster on the Barr Report stated in August of 2008.



> 'Polycycloglutaracetal' and glutaraldehyde for plants
> 
> Having recently stumbled across various discussion threads relating to the use of Glutaraldehyde in the aquarium to promote aquatic plant growth, I thought I would research the topic a little more for my own edification. This is what I came up with. The commercially available product by Seachem called Flourish Excel TM has a rather oddly termed compound called ‘Polycycloglutaracetal’. Based on the curiously formulated name, it appears that Seachem just made it up to describe a concoction of aqueous Glutaraldehyde with one or more chemicals of undisclosed nature. It therefore follows, that you will not find this fictitious compound on any MSDS or official chemical register of compounds. Of course it is widely known that glutaraldehyde has algicidal properties at specific concentrations, along with uses as a fixative for electron microscopy. Glutaraldehyde is a small compound made up of a short carbon chain with an aldehyde functional group at each end. The chemical formula is HCO-(CH2)3-CHO. The terminal aldehyde groups are quite reactive and in aqueous (i.e. in water) form (> pH 7.0) glutaraldehyde molecules readily forms cross-links to form polymers of varying length. These oligo-/polymers also readily combine with nitrogen groups in proteins to form additional cross-links. Hence, this is the likely origin of ‘Poly-‘ and ‘–cyclo-‘ in the name ‘Polycycloglutaracetal’; the rest of the name is self-evident. So, as it would appear, Seachem has formulated the name to describe the behaviour of glutaraldehyde in water with the additional of some type of protein or other organic compound. The polymerisation capacity of glutaraldehyde to proteins is widely used in biomedical fields in regeneration of collagen and ligaments. Moreover, cross-linking of aqueous Glutaraldehyde with proteins involves more than a dozen different forms (e.g. isomers) depending on solution conditions (e.g. pH, temperature, etc.). These isomers are in equilibrium, so whatever isomer predominates in solution will depend on ambient conditions, and appears not to influence the beneficial net effect of the compound to plant growth. The figure provided by Seachem to describe the general structure of ‘Polycycloglutaracetal’ also corresponds well to the rationale proposed here (see


http://www.seachem.com/support/Arti...aria.
SLW [plants first,... fish will follow


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## sfshrimp (May 24, 2016)

The stuff is junk. There are so many threads about people using as a replace for c02 or to combat BBA. I think the big question is what the end goal is in using it.


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## Seattle_Aquarist (Jun 15, 2008)

Hi sfsshrimp,

You are certainly entitled to your opinion. 

However based upon my experience using Excel/Glutaraldehyde for over 8 years I disagree that assessment. I started using it when I read *this paper by Dr. Greg Morin* after seeing it referenced on thekrib.com website. Dr. Tom Barr, in his presentation to GSAS last month, covered how glutaraldehyde enhances plant growth by providing carbon molecules for plants to utilize in the Calvin Cycle of photosynthesis.

As for my personal experience with Excel/Glutaraldehyde. Here is a low tech 10 gallon tank with 2X10watt CFL bulbs, fertilized using the EI method and utilizing Glutaraldehyde as the source for carbon molecules. The tank had be set up 10 weeks when the picture was taken.


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## sfshrimp (May 24, 2016)

Seattle_Aquarist said:


> Hi sfsshrimp,
> 
> You are certainly entitled to your opinion.
> 
> ...



If it works, it works, but how do you know you are having success because of the excel? The rotala looks nice. What I was trying to assess is what the problem is that you need the excel in the first place, because the poster has concerns about toxicitiy.


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## MCFC (Feb 12, 2017)

I spilled a drop of Excel on a pair of brown Carhartt pants and it turned into a toonie-sized white patch!


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## sfshrimp (May 24, 2016)

MCFC said:


> I spilled a drop of Excel on a pair of brown Carhartt pants and it turned into a toonie-sized white patch!


Lol "tonnie." Is it a little bit loony also?


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## MCFC (Feb 12, 2017)

@sfshrimp - You'll have to excuse my weird words, I'm from Canada eh. But more to your question: Yes, it was kind of like a loonie, only bigger, like a toonie.


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## sfshrimp (May 24, 2016)

MCFC said:


> @sfshrimp - You'll have to excuse my weird words, I'm from Canada eh. But more to your question: Yes, it was kind of like a loonie, only bigger, like a toonie.


Awesome. I'm talking tiny toons, but thanks for showing me a quarter, lol. Are you guys getting concerned yet that a bunch gun toting American people are fleeing and want to live in your country now? Maybe build a mountain so no one can enter? Ecological wall bro. Human iwagumi. >


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## MCFC (Feb 12, 2017)

@sfshrimp - I thought it was the gun-toting citizens that wanted to stay and make their country great "again"? But no, I don't think we're too concerned. There is an awful lot of space up here and not that many people haha.


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## sfshrimp (May 24, 2016)

MCFC said:


> @sfshrimp - I thought it was the gun-toting citizens that wanted to stay and make their country great "again"? But no, I don't think we're too concerned. There is an awful lot of space up here and not that many people haha.


Yea. I mean besides enjoying the outdoors, we are busy mining super heavy coal in West Virginia smoking Salems with a child president who is helping his daughter sell her Chinese clothing at JC Penny and funding nice trips to hunt exotic and rhino cat hunts in Africa for some virility with A/C. Meanwhile, lower level humans are still paying taxes and trying to figure out how to make loach happy. 

I was recently at mar a lago playing golf up in the blue gill room, it was a real hearthy laugh time between the propecia dosing and kushner's barracuda tank. He really got off feeding a goldfish to his flock while he held his kris vector. My loach looked embarrassed, but it did a good job at nibbling at Ivanka's ovaries, and a good clip of Barron's umbelical cording line. No more air stone for the little boy! We spent most of the remainder dividing quotients of Don's cut up speed. Tomorrow is a new day, but we don't take anything super serious because we are loaded up.


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## clownplanted (Mar 3, 2017)

Seattle_Aquarist said:


> Hi sfsshrimp,
> 
> You are certainly entitled to your opinion.
> 
> ...




Are you using excel. Or metricide? Great looking plants. 

Nevermind. Helps if I read and saw you mentioned excel. Coffee has not kicked in yet lol


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## Seattle_Aquarist (Jun 15, 2008)

Hi @clownplanted,

I used Seachem Flourish Excel until approximately October of 2008, for the last nine years I have been using glutaraldehyde. I have some background in Chemistry so I purchase biological grade glutaraldehyde and mix my own 1.5% solution, it currently costs me about $1.30 to mix up 500 milliliters of solution. The 10 gallon in the picture was dosed with glutaraldehyde.


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## jeffkrol (Jun 5, 2013)

Some things need to be handled more cautiously than other things. Excel/glut is one of those..


> Workers can be exposed to glutaraldehyde through inhalation or skin contact. Health effects that may occur as a result of exposure to glutaraldehyde include but are not limited to the following:
> 
> Throat and lung irritation
> Asthma and difficulty breathing
> ...





> Abstract
> 
> Glutaraldehyde (GA) is widely used in the industrial, scientific and biomedical fields. Many adverse health effects on humans have been reported in association with biomedical uses of GA, with 2-3.5% aqueous GA solution generally used for cold sterilization and GA exposure ranges of 0.001 to 2.6 ppm for this type of use. GA is metabolized extensively to CO(2), but urinary excretion of it is low. Sensory irritant effects, sensitization of skin and respiratory organs and other symptoms have been reported among endoscopy nurses and medical radiation technologists. The prevalence of chronic bronchitis and nasal symptoms in humans is significantly correlated with peak concentrations of GA exposure. The extent of primary skin irritation depends on the duration and site of contact, and the severity of symptoms is dose-related. Chronic inhalation affects the nose and respiratory tract, and lesions become severe with prolonged duration of exposure. Increases in neither mortality nor tumor incidence have been found in workers with less than 0.2 ppm GA exposure, no evidence of carcinogenic activity has been obtained in experimental animal studies. There has been no clear evidence of genetic toxicity of GA in either in vitro or in vivo studies, and neither developmental nor reproductive toxicity has been found in humans or animals. To prevent hazards from GA exposure, use of closed-system, fully automated washing machines is recommended, since numerous symptoms have been found in individuals with less than 0.05 ppm GA exposure, the recommended peak exposure limit in many countries.


https://www.ncbi.nlm.nih.gov/pubmed/16612035
https://www.google.com/url?sa=t&rct...zJ9TUFQ6w&sig2=cRZ3bclEk-nq-2FWG-xFSw&cad=rja


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## Seattle_Aquarist (Jun 15, 2008)

Hi jeffkrol,

I agree 100%. If you don't know how to handle chemicals properly, wear proper protective gear, or fail to provide adequate ventilation when working with chemicals the result could be perilous.


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## longgonedaddy (Dec 9, 2012)

sfshrimp said:


> If it works, it works, but how do you know you are having success because of the excel? The rotala looks nice. What I was trying to assess is what the problem is that you need the excel in the first place, because the poster has concerns about toxicitiy.


I know it works. I used the full Seachem line on my previous tank. Stopped using only Excel for about a month, plants did not do as well. Started up with metricide, and less than a month into it plants were back to where they were while on Excel. Similar results with both products, distinct drop in plant health without either.


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## clownplanted (Mar 3, 2017)

Seattle_Aquarist said:


> Hi @clownplanted,
> 
> 
> 
> I used Seachem Flourish Excel until approximately October of 2008, for the last nine years I have been using glutaraldehyde. I have some background in Chemistry so I purchase biological grade glutaraldehyde and mix my own 1.5% solution, it currently costs me about $1.30 to mix up 500 milliliters of solution. The 10 gallon in the picture was dosed with glutaraldehyde.




Being a chemist so obviously you have knowledge on this stuff would you say not to use metricide but in my case not comfortable mixing my own stuff to stay with excel? Just want a solution that is as good as excel but not have to pay for mostly water just like going dry ferts over pre mixed. 

Is metricide not biological?


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## Seattle_Aquarist (Jun 15, 2008)

Hi @clownplanted,

If it were me, and I was concerned, I *would* use Metricide 14 (2.6% glutaraldehyde) or Metricide 28 (2.5% glutaraldehyde) without the activator. Since the two Metricide probducts are about the same strength then I would use them "straight from the bottle" although you may want to carefully transfer them to a smaller container (wear gloves, avoid the fumes, protect your eyes). You can use 2.88 ml (call it 3.0 ml) of straight Metricide to have the equivalent of 5.0 ml of Seachem Excel. Hope this helps! No, to the best of my knowledge Metricide is not biological but is chemical - it kills germs and bacteria and does have some algicide properties.


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## clownplanted (Mar 3, 2017)

Seattle_Aquarist said:


> Hi @clownplanted,
> 
> If it were me, and I was concerned, I *would* use Metricide 14 (2.6% glutaraldehyde) or Metricide 28 (2.5% glutaraldehyde) without the activator. Since the two Metricide probducts are about the same strength then I would use them "straight from the bottle" although you may want to carefully transfer them to a smaller container (wear gloves, avoid the fumes, protect your eyes). You can use 2.88 ml (call it 3.0 ml) of straight Metricide to have the equivalent of 5.0 ml of Seachem Excel. Hope this helps! No, to the best of my knowledge Metricide is not biological but is chemical - it kills germs and bacteria and does have some algicide properties.




Thank you very much. You have been a great help. 


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## steveo (May 25, 2012)

sohankpatel said:


> So, I have conversed with some members of my local fish club, and one of them is adamant about how excel is not the best thing for our tank. Not as in co2 VS excel. It is more along the lines of, is it worth interacting with a substance that is really not good for us to use? He says, and from what I have gathered, that Glutaraldehyde is a fairly toxic and harmful substance. It IS in the same family as formaldehyde after all. He was saying that Excel is actually not raw Glutaraldehyde, it has been broken down along a few "steps" to the path that plants need to metabolize it. He recommends that people only use Excel, and not Metricide 14, because Metricide is in it's raw form, and in a higher concentration. Look at the MSDS, it really is nasty stuff. This is in no way intended to stop people from using excel, I think it is a great product, I just wanted to put it out there that this substance is fairly toxic to people and animals.
> Maybe some of you that know more than me can chime in?


As you noted, it is a great product! I use it in all my planted tanks. Plant growth is accelerated and algae gets knocked back. If using Metricide 14 for your source of glut, dilute properly and handle with care. This could include wearing gloves, mask when mixing and washing your hands. I really don't believe glut, in either Excel or Metricide, is anything to fear when handled and stored properly.


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## AbbeysDad (Apr 13, 2016)

Mix 200 ml distilled water to 300 ml Metricide 14 for the same glut concentration as Excel.


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## fusedpro (Dec 29, 2011)

Just an FYI, I would stick with Metricide 14 and not Metricide 28. The MSDS makes no mention of it, but the website lists the 28 variant as having a surfactant (soap). I overlooked this bit before ordering a jug, effectively wasting $25. I poured a small bit into a cup, gave it a swirl, and it was definitely sudsy. There are reports of people using 28 with no repercussions, but I'd rather be safe.

In either case, just want to reiterate to not use the little bottle of activator solution.


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## sfshrimp (May 24, 2016)

steveo said:


> As you noted, it is a great product! I use it in all my planted tanks. Plant growth is accelerated and algae gets knocked back. If using Metricide 14 for your source of glut, dilute properly and handle with care. This could include wearing gloves, mask when mixing and washing your hands. I really don't believe glut, in either Excel or Metricide, is anything to fear when handled and stored properly.



Sounds great between the gas, glut, viberza and soap hands. Why do you guys even need this? Maybe keep your tank slim? So many expert solutions with 0ml.


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## roadmaster (Nov 5, 2009)

I have been using Metricide 14 (tossed the activator bottle), at 15ml a day in 80 gal low tech non CO2.(tank is nine month's running)
Resisted for a long while, but am pleased with improvement after a couple month's use .
Excel too expensive for 80 gal.
Celebs Rainbow's,platy's,Cherry shrimp,corydoras,Fancy guppies,Swordtail's,Pleco's,all just keep on doin what they do.(need to net out some babies this weekend)
I draw the stuff out of the jug with turkey baster that is marked on the side with ml measurement's and squirt it in the tank daily.


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## AbbeysDad (Apr 13, 2016)

Glutaraldehyde is used to sterilize heat sensitive medical and dental equipment/instruments.
So anything that sterilizes is a toxic element. But it really comes down to concentration. Aspirin or Tylenol can kill you if you take too many! For that matter, the ferts we use could be considered toxic to fish at very high levels.
The point here is 1) it's diluted enough to not be toxic, and 2) it readily decomposes in the aquarium to provide a source of plant usable carbon. At the same time, it seems to inhibit the growth of algae.

I resisted using Excel until I 'inherited' some black beard algae from some evilbay plants I bought (a deal too good to be true....and wasn't). I later switched to Metricide because of the huge cost advantage. I haven't been using it recently as I wanted to [better] judge the effects of my DIY CO2, but I am now seeing an increased growth of green algae.
In any case, I used it for about 8 months with no apparent negative effects and there was a noticeable increase in plant growth.


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## IntotheWRX (May 13, 2016)

i put excell into a plastic food sauce squirt bottle so i can just give a squeeze here and there and it doesn't drip all over my hands.


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## clownplanted (Mar 3, 2017)

Gave me idea. Will get an extra fert 500ml bottle as it's mess free also. No risk of mess or spill. Sweet. 










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