Originally Posted by andrew__
Well, that was a long read (with most of the same questions and answers every 3-6 pages
) and I've got a question. A bunch of times people have said things like "It's not CO2 so fish won't die from low oxygen levels" etc, however on page 6:
So is this last sentence not correct or is CO2 being produced at low enough concentrations that everyone dismisses it off hand?
Anyway, This thread was a good read, going to be starting to use Excel for plant growth purposes at Seachem's suggested dose, I'll let you know if I start to see an impact on algae at that point.
Andrew, first off, I think it's important to dismiss the oxygen myth... CO2 does not displace oxygen in the water molecule as these two gasses are stored in different 'areas' of the molecule itself. So this has never been an issue, the effect CO2 has on O2 levels within a water molecule is neglectable. Above a certain concentration, CO2 levels themselves become toxic.
When it comes to Excel, it's the product itself (a disinfectant basically) that can pose a direct danger at certain concentrations. The organic carbon becomes available once bacteria have broken down Excel into simpler forms. This form of carbon is unlike CO2 gas, it does not effect PH for example. Unsure of what it effects, if anything, but the two are quite different. My guess is that when Excel is mistakenly over-overdosed, it's the glutaraldehyde that is responsible for any problems rather than the amount of organic carbon that will become available shortly after.