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Low Tech Fertiliser Dosing. Whats your technique?


7 Apr 2008
nr Bath
Hi all,
So, the question is, whether fish and microbes provide them more CO2 than oxygenation? @Wookii took for granted that oxygenation makes the water saturated with CO2 as much as possible. While I believe that this is not the case, except in the afternoon, perhaps.
I don't understand where this going.

Plants are net CO2 consumers, it isn't a suggestion or a hypothesis. The <"oxygen we breathe">, <"fossil fuels we burn"> and <"the steel we use"> were entirely created from the difference between the CO2 consumed and oxygen evolved during photosynthesis.

@Geoffrey Rea <"measured dissolved oxygen over a 24 hour period"> in his high tech tank, with some surprising findings.

I don't think any-one is arguing that <"dissolved oxygen isn't important">, I'm certainly not, in fact quite the opposite.
The reason for all this is that the prime metric we are interested in is dissolved oxygen, and nearly everything else is just "froth". We want the biological filtration media to be fully oxygenated (for the oxygen supply to exceed the oxygen demand). In the case of a planted tank, with your filter, it is going to be quite difficult to arrive at a situation where you have de-oxygenated media.
We have a thread <"maximising dissolved O2"> and another on <"maximising CO2 in a low tech tank">.

Personally I like some <"laminar flow"> (and <"direct aeration">) to replenish the <"levels of dissolved gases">. As general rule as the bioload get larger the gas exchange surface area <"also needs to gets larger">, this is to both outgas CO2 and replenish dissolved oxygen.

If we measure the <"diel variations in pH"> it gives you a pretty good indication of the CO2:O2 balance.

cheers Darrel
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