Excel Initial Dose

[Frank158]

I've always had a question about the initial dose of Excel. According to the bottle it is recommended that you dose the tank 5ml per 10 gallons then daily dose is 1ml per 10 gallons. I've also read that Excel completely dissipates after 24 hrs therefore the reason to dose daily.

So the question is, why perform the 5x initial dose if it all dissipates the next day anyway? Seems like a waste to me. I typically do my water change a few hours before the lights go on and think that I can just stick with the daily dose.

 

[burr740]

If you're battling BBA it could be useful. That's the only benefit I can see from the large post water change dose.

 

[Frank158]

So in other words your saying that the 5x initial dose is kinda of a waste of Excel

 

[rajkm]

I think there is more to it.
One thing for sure is that it reacts with iron to convert Fe3 to Fe2. So I am sure there are more ionic reactions which could result in wastage.. that's just a guess.

 

[VaughnH]

The 5 ml/10 gallons dosage is very hard on certain plants, setting them back considerably (vals, for example). I stopped doing that dosage a few years ago, and have never regretted it.

 

[Frank158]

Yes I agree. I'm just curious about why the initial 5x dose in the first place.

 

[Seattle_Aquarist]

Hi Frank158,

I asked Seachem the exact same question, the answer was appropriate. If we are trying to attain a certain ppm of available carbon molecules then when we do a significant water change we have reduced the available carbon molecules in the tank. The higher 'Initial Dose' amount is how the carbon molecule ppm is brought back to the ppm level before the water change.

 

[Frank158]

Thanks for that. I'm an accountant not a chemist so will have to take Seachem's answer at their word.

 

[Dale Hazey]

Search their forums and some of their people will give slightly different answers about the life of Excel in the water column. Definitely dose before lights come on.
Some posts by seachem state Excel will only last 11-12 hours, some say 24 hours.

I wouldn't bother with the post W/C dose.
Tom has suggested dosing 1.5-2x the daily dose in the no CO2 article. I did that for a long time and it worked very well.

 

[VaughnH]

I wouldn't bother with the post W/C dose.
Tom has suggested dosing 1.5-2x the daily dose in the no CO2 article. I did that for a long time and it worked very well.

This is why I changed to a 2X Excel dosage, daily, with no water change "super dose". When I read the test report of API's version of Excel, where they don't do the "super dose", I realized that what that report really showed was the advantage of not doing that "super dose". All it did, that was measurable was slow the initial growth of plants. (Not all plants, but some of them.)