Not really sure why you are giving a breakdown for Glutaraldehyde here?
Why weaken the Excel dosing?? I think you are a bit off track here OS.
I must have not been clear. I meant that you can dilute the Metricide 14 with distilled water to be equal to excel, or like I do, you can just dose it at 100% and either use less metricide or dose more glutaraldehyde.
Metricide contains the only active ingredient in Excel and would save the average user a TON.
2x2L of excel(just over 1 gallon, would run you 62 bucks(before shipping) from Big als.
(just the first I chose, not sure if it is cheapest)
1x1 gallon of Metricide 14 is 24 bucks shipped for me, from DealMed
Now, assuming you dose it straight, 100%, not reduced at all, Metricide is 38% the cost of Excel. You would be paying 62% more for a lower concentration of Glutaraldehyde.
Now, lets assume that you dilute it at a ratio of 1.5(Glutaraldehyde):1(distilled water) you end up with a percentage of 1.8% Glutaraldehyde--just over the excel level. This will make your 1 gallon of Metricide turn into 1 2/3 gallon(1.666) gallons of Excel equivalent.
So, now, if diluted you would have the equivalent of about 100 dolars(before shipping) worth of Seachem Excel. On a 50 gallon tank, dosing at seachem dosing of 5ml per 50 gallons... you have 1261 doses... For 24 dollars.
If you don't dilute it, but still dose 100%, you would have 757 doses(on a 50g tank) and be more concentrated. On my 75 gallon tank I dose 10ml daily/every other day of 100% metricide 14(2.7%). I have 378 doses in my bottle.
The value is simple.
All for 24 dollars shipped to my door and about 3 minutes of math.