# Metricide dosing?



## Seattle_Aquarist (Jun 15, 2008)

Hi aquanauts,

There are two Metricides, Metricide 14 and Metricide 28. If you are referring to Metricide 14 which is 2.6% glutaraldehyde then 2.88ml of Metricide 14 equals 5.0ml of Seachem Excel (1.5% glutaraldehyde). For a 5 gallon tank then the dosing would be:
Initial Dose = 1.44ml Metricide 14
Daily Dose = 0.29ml Metricide 14

If you want to make an Excel strength mixture, then add 42.3 ml of water to 57.7 ml of Metricide 14 or roughly 4 parts water mixed with 6 parts Metricide 14 equals Excel strength solution.


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## Raymond S. (Dec 29, 2012)

I bought the 28 by mistake. What is the dose for that one.
I was using the Excel in a 10g tank @ 2 ml per day.

I only have one 10g tank that I was using this in so I really didn't want a gallon.
I saw the Quart and clicked on purchase before I noticed it being the 28.


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## Seattle_Aquarist (Jun 15, 2008)

Hi Raymond S.

No problems, Metricide 28 is 2.5% glutaraldehyde. Seachem Excel is 1.5% glutaraldehyde. Therefore 3.0 ml of Metricide 28 equals 5.0 ml of Seachem Excel.

For a 10 gallon tank using Metricide 28 the doses would be:
Initial Dose = 3.0 ml
Daily Dose = 0.6 ml 

If you want to make an Excel strength mixture, then add 40.0 ml of water to 60.0 ml of Metricide 28 or 4 parts water mixed with 6 parts Metricide 28 equals Excel strength solution exactly.


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## Raymond S. (Dec 29, 2012)

Well like I said, I'm using 2ml per dose of Excel each day.
So what I need is the amount of Metricide 28 that equals 2ml of Excel.
Since it is said to dissipate in 24 hrs, I see no function in making an initial dose
or a different size dose just after the water change like the bottle of Excel
suggest.
Appreciate your help. See in your signature that you have a 30L tank.
If I had no other hobbies I'd likely have a 75g tank as my favorite.
But I had a 30L when I was 14 and I'm trying to get one now as it's likely
my favorite size other than the 75g.
I don't watch my tanks from across the room. I place them on a stand that
makes them eye level when your sitting in a regular chair and that chair is
right in front of the tank. When looked at that way you can't see all of the 
30L without moving your chair. So what is the point of a longer tank ?
And I do fish like Elassomas so the 18" 40B would be counterproductive
for seeing my fish or details in the back of the tank. So the 30L is perfect.


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## Seattle_Aquarist (Jun 15, 2008)

Hi Raymond S.

The reason the Initial Dose after a >40% water change is five times (5X) the Daily Dose is to replenish the carbon molecules that were lost with the water change; once the carbon molecules have been replenished to normal levels the Daily Dose maintains the available carbon molecule level.

In answer to your question, 2.0ml of Seachem Excel would equal 1.15ml of Metricide 28.


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## chipwich74 (Sep 16, 2018)

Hi Roy... I have seen a number of your posts that state that Metricide 14 should be diluted to become an Excel equivalent since Metricide 14 contains 2.6% glutaraldehyde ans Seachem Excel contains 1.5% glutaraldehyde. Upon closer inpection of the label on my Seachem Excel bottle, its states that it contains 2.5% of Polycycloglutaracetal. I assume Polycycloglutaracetal is just their trademark name for glutaraldehyde but the concentration is puzzling me because if Polycycloglutaracetal is a 1:1 equivalent for glutaraldehyde, then this would suggest no dilution is needed. I contacted Seachem to see if they have changed their formulation or increased the concentration and they say no. It is still the original formula. So should we still dilute Metricide as though Excel should be at 1.6% glutaraldehyde?


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## jeffkrol (Jun 5, 2013)

Raymond S. said:


> I bought the 28 by mistake. What is the dose for that one.
> I was using the Excel in a 10g tank @ 2 ml per day.
> 
> I only have one 10g tank that I was using this in so I really didn't want a gallon.
> I saw the Quart and clicked on purchase before I noticed it being the 28.



doesn't Met28 have added stuff you don't want?


> Contains surfactants


Met14


> Contains no surfactants


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## burr740 (Feb 19, 2014)

I believe the only difference in the 14 and 28 is how long it lasts as a sterilizing agent using the activator as it is intended. The 14 is good for 14 days, the 28 for 28. 

Which is irrelevant because we dont use the activator


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## Seattle_Aquarist (Jun 15, 2008)

chipwich74 said:


> Hi Roy... I have seen a number of your posts that state that Metricide 14 should be diluted to become an Excel equivalent since Metricide 14 contains 2.6% glutaraldehyde ans Seachem Excel contains 1.5% glutaraldehyde. Upon closer inpection of the label on my Seachem Excel bottle, its states that it contains 2.5% of Polycycloglutaracetal. I assume Polycycloglutaracetal is just their trademark name for glutaraldehyde but the concentration is puzzling me because if Polycycloglutaracetal is a 1:1 equivalent for glutaraldehyde, then this would suggest no dilution is needed. I contacted Seachem to see if they have changed their formulation or increased the concentration and they say no. It is still the original formula. So should we still dilute Metricide as though Excel should be at 1.6% glutaraldehyde?



Hi @chipwich74,

I don't say folks should dilute Metricide to Excel concentration; however some have asked how to do it. I just downloaded the Seachem Flourish Excel Safety Data Sheet form their website (see attachment below). Section 3 does not state the ingredients nor the concentration; it just states:


> * Proprietary aqueous solution of salts. The identity and weight of proprietary, non-hazardous,
> main ingredients are withheld as a trade secret. Other ingredients are present in amounts less
> than 1% and are non-hazardous.


The original testing of the glutaraldehyde concentration was done Apr 12, 2006 (see 9:09 pm post) so it is possible that Seachem has changed the concentration level over the years. If you could take a picture of the label showing the information about "2.5% Polycycloglutaracetal" and post it in this thread it would be helpful. 

But what is "Polycycloglutaracetal". Apparently it is a 'proprietary' ingredient; poly = 'many molecule'; cyclo = 'in a ring'; glutarcetal = derived from glutarate. If the formula has not changed then it is still equivalent to 1.5% concentration glutaraldehyde according to the testing done in 2006.


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## jeffkrol (Jun 5, 2013)

It's listed on the bottle as (can supply photo if needed):
2.5% polycycloglutaracetal..


OLD excerpt from the Seachem MSDS..



> Here's an extract from the MSDS of Flourish Excel from Seachem.
> 
> /ParaGuard, HealthGuard , Pond HealthGuard, *Flourish Excel*,
> StressGuard [NFPA 1,0,1]:
> ...


Kind of a mess if you ask me:


> I did my research and found that the formula for Excel appears to have changed. Old posts said that Excel was 1.5% Glutaraldehyde. New Excel label says that its 2.5% Polycycloglutaracetal , but the dosing instructions remain unchanged:


https://www.aquaticplantcentral.com...134002-has-seachem-excel-changed-formula.html


Want to make it messier??
Check out the photos..and msds..


> 2% acetal form of 1,5 pentandial


http://blog.naver.com/PostView.nhn?blogId=sueay&logNo=220379143748&redirect=Dlog&widgetTypeCall=true

(CAS) 111-30-8
http://www.chemicalbook.com/ChemicalProductProperty_EN_CB3762723.htm
in 2008

current US MSDS:
https://www.dropbox.com/sh/iu6wapsz...l=0&preview=Flourish+Excel+SDS+20160107+1.pdf

stuff
https://www.osha.gov/laws-regs/standardinterpretations/1985-12-10


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