# Has SeaChem Excel changed the formula



## tiger15 (Apr 9, 2017)

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:

"On initial use or after a major (> 40%) water change, use 1 capful (5 mL) for every 40 L (10 US gallons). Thereafter use 1 capful for every 200 L (50 US gallons) daily or every other day."

I am wondering if SeaChem is playing with words to frighten people into buying cheaper Metricide substitute. There is a thread that demystified Polycycloglutaracetal. It is no different from Glutaraldehyde

http://www.aquariumlife.com.au/showthread.php/54446-Excel-vs-Glutaraldehyde

I am not concerned about the change of ingredient just by name, but want to verify if Excel has indeed increased the concentration from 1.5% to 2.5% Glutaraldehyde. If so, I can just dose Metricide 14 (2.6% Glutaraldehyde) the same as I would dose Excel with no adjustment.


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## hoppycalif (Apr 7, 2005)

I can't answer the question, but I do dose Metricide 14 the same as Excel, 1 ml per 10 gallons of water. I dose it daily, 5 ml in about 50+ gallons of water in my 65 gallon tank. It is working great for me. I use it to avoid BBA attacks which my DIY CO2 would lead to as the concentration of CO2 in the water varies from day to day.

Most people mix Metricide with water to reduce the concentration to 1.5%, but I have never seen any reason to do so.


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## burr740 (Mar 6, 2015)

They are probably just trying to discourage folks from going with Metricide instead, by making you think it's something different. And it might be a slightly different compound. Though I suspect it's a matter of semantics more than anything.

Either way its a sound business move on their part. Nothing wrong with that.

Like Hoppy, I used Metricide straight for a couple years with good success, following Excel's recommended dose.

Using 2x the dose as a matter of fact. because that's what I was doing with Excel when I switched.


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