Nope it was very helpful considering all my plants have low demands in c02The Flourish Excel FAQs confirms this (http://www.seachem.com/support/FAQs/FlourishExcel.html).
As liquid carbon isn't a gas, surface agitation doesn't appear to affect concentration.
I'm trying to design a planted tank for fish from faster flowing streams that need higher levels of oxygen all of the time.
Aside from photosynthesis, surface agitation seems to be the best way of getting oxygen into the water. However, surface agitation will degas CO2.
Switching an air stone on after lights out means you can get oxygen in when the plants are not photosynthesising. Howeve, high swings of CO2 level appears to increase BBA.
Also, to achieve required CO2 concentration at lights on, the air stone would have to be switched off two hours before. For two hours there would be little oxygen coming into the system from either the air stone or the plants and increasing CO2 levels. Not good for the fish.
Therefore, I'm planning to have surface agitation, adding liquid carbon and selecting plants that Tropica (or other suppliers) state require a lower demand for CO2.
Not sure if this helps. This doesn't seem to be a common approach.
Thank youNo, surface agitation degasses the co2 you try to dissolve, while liquid co2 is not a gas but a chemical compound that can play a similar role co2 plays during the photosynthesis
Jordi
If you have high levels of flow you will maintain CO2 and O2 levels close to their equilibrium values with the atmosphere. I recommend this approach, partially because I like the tank to be well oxygenated at all times.I'm planning to have surface agitation, adding liquid carbon and selecting plants that Tropica (or other suppliers) state require a lower demand for CO2.
Systems with a large gas exchange system (via a wet and dry trickle filter, a large surface area to volume tank or a linear flow) will maintain higher CO2 levels than other low tech systems when the plants are actively photosynthesizing.
Only when lights are on. Degassing CO2 via an airstone when lights are off and starting to add CO2 before lights are on does not cause BBA.Howeve, high swings of CO2 level appears to increase BBA.
3ppm I read somewhere.Any ideas what are the maximum ppms of co2 that we can maintain just via agiatation
Temperature is relevant, but you can largely ignore air pressure and the conductivity of the water, unless you are a marine aquarist and live in Denver.I understand T and P play a big role here.
I don't have any figures specifically for CO2, because with polluted water you are mainly trying to out-gas the CO2, but if you look at oxygen, you can maintain it pretty close to saturation, even with larger BOD values than you would get in an aquarium.Any ideas what are the maximum ppms of co2 that we can maintain just via agiatation Darrel?I
However the answer it gives is 4.25 x 10-7 M. Some one needs to convert this the ppm.
2-3 PPM vs 0.5 PPM...
I think the 2-3 PPM info is probably from http://www.hallman.org/plant/booth2.html .
Although the measurement was done by using LaMotte's test kits, the margin of error of 2 PPM
and the resolution of 1 PPM might be too coarse for this measurement. And it's an aquarium,
there must be some CO2 producing activities in it.
All other people and documents I've found state ~0.5 PPM.
I don't remember exactly how solubility of oxygen/CO2 is changed with altitude though, but IIRC with higher altitude pressure is decreasing and therefore solubility should decrease too.