I had not thought about using hydroponic root systems for the potential for storing O2 and CO2 etc.
Mainly just focusing on the shoot, as it's the part that does the O2 production.
The data just gives the ranges I measured over the same time frames on several tanks.
There is noit an additive effect.
I think exposure to pure CO2 gas ut of the water would produce the strongest O2 production afterwards.
Air would be second followed by the thick viscous medium of water with CO2 mist+ good dissolved CO2, then finally CO2 all dissolved with no non dissolved gas phase.
That's what I would predict anyway.
The goal here is not so much to have folks drain their tanks down to 95%, that's impractical with fish and other issues. It's the learn a bit more about how algae and plant production/growth rates are effected by O2 and CO2.
Few do much thinking about CO2, they would rather waste all their time on haggling over NO3 and PO4, or Ca and Mg.
Those are important as well, but CO2 is 40-50X more important in terms of dry weight biomass.
When we see dramatic increases in pearling, we should figure out a good way to measure that increase.
O2 meters are about the best measurement tool we have for that. But perhaps observations alone can help other folks.
It might not work, but we have to try
I think we still can see some evidence that the gas phases do increase growth and pearling with these methods not using an O2 meter.
One thing to think about is how might we be able to produce that much pearling and growth all week long and not just after the water change?
You need to see that intense pearling, health and growth first........then you have a max growth rate to compare to.
That is now your goal, the bar you set to achieve for your tank's growth.
You also should focus on CO2 if you use EI, EI rules out the nutrients leaving only the CO2 as the dependent variable.
We can deliver the CO2 a number of ways.
ADA and many other delivery in the gas and dissolved phase.
A combination of both appears to provide the best growth and what I would hypothesize.
So CO2 gas phase + dissolved would give the best results.
We are limited by practical matter with exposure to air or pure CO2 gas for brief periods, but we might observe and learn from those exposures and observations also
Many folks find that when they switch to CO2 mist, they have almost too much pearling, intense growth etc and algae makes a hasty retreat.
Other folks appear not to have much luck, but it might be they have not set the tank up right etc, not adding enough CO2, have other confounding issues with their independent variables etc.
Yes, it is ideal I would think to have CO2 come on about 1/2 hour before the lights come on. Then shut off about 30-60 minutes before the lights go off.
That way, as soon as the lights come on, the plants have plenty of CO2 and get going right away.
You might try the glass air bubble method to see.
I would also suggest looking at the DIY internal venturi diffuser I designed, it acts like the glass a little bit.
If you place the downward firing gas mist diffuser above a plant, it will grow very intensely compared to a similar plant on the other side of say a 4 ft long tank.
Now the pH will be the same throughout the tank mind you, but the growth will be different.
So the dissolved CO2 is fairly even, but the gas phase is the main difference in the treatments.
There are many designs you might try out here, but proving them will generally require a DO meter and relate that to growth rates.
Regards,
Tom Barr