Liquid Carbon Joke?

[staygreen]

I have a planted 15g tank with 1.6 watts per gallon. I have been worried about my CO2 levels being low. I calculate the CO2 by the pH and the KH---for the last two weeks it has been about 4mg/l according to this test.
I think this is probably the limiting factor on growth in my plants. The annoying thing is that I have been using Flourish Excel supposed carbon source but I dont think it is doing anything! I retested my KH and Co2 after adding Excel and there was no change, I have been doing about 1 ml a day--should I up the dosage?

What is everybodys experience with this product? Is it legit? Or is it just liquid bull****?

Maybe I should set up a yeast Co2 system...

 

[OrionGirl]

My understanding is that the Flourish product is valuable, but I am not sure if you can calculate the carbon from these supplements that same way you can from CO2, since it it a different form of carbon. The calculation relies on the acidity of CO2, which is an acid. Since the liquid supplements don't alter your pH and don't have the acidity to use of KH, I don't think it would be detected in this way.

Someone with a better understanding of chemistry might know more though.

 

[RTR]

OG got it in one. CO2 detection techniques do not work for Excel because it is not CO2, it is an organically linked carbon which plants can use the same was they do CO2 - from which they split out the carbon and organically link it for use.

Excel is good stuff - it is not full replacement for compressed gas CO2, but it is a lot better than nothing, a whole lot. I do use the stuff.