Hey all,
While staring at my tank last night, having previously just gassed my fish and had to carry out an emergency water change, I had this idea of why all our plants pearl much more in the 12 hours after water changing.. see what you think, its just a theory, and might be full of holes.
Pearling happens when the plant is producing more O2 than can be effectively dissolved into the water column.
When we add fresh water, the water we put in is pretty super-saturated with O2.. so could it be, that under the minimal pressure of a fish tank, the saturation levels are just too high in the water to accept any more O2 from the plants?
Using my scuba knowledge about partial pressure and gas theory, to super-saturate a liquid with a gas, a higher partial pressure can be achieved by putting the liquid under pressure, much like a soda bottle.. when you release the pressure on the soda bottle, the gas (in this case co2) come out of solution and turns back into the gas phase. This is what happens when a diver comes up to fast, and nitrogen comes out of solution inside his/her body, causing micro bubbles in the nervous system.
Could this be whats happening when weve added fresh o2 laden water? The partial pressure of the O2 is purely to high to accept new gas from the plants.. so it remains out of solution as bubbles...
so.. if this is correct.. the excess pearling we see when weve carried out a water change, isnt actually a growth spurt, its purely o2 with nowhere else to go.
With no o2 measuring equipment i cant test this theory.. although it stands up on paper.
This would also explain why it takes a short while for the plants to start pearling when lights go on. The O2 levels in the water would have stabalised over night with no fresh addition of O2 from the plants (surface movement cant super-saturate).. after a few hours, the O2 levels rise to capacity, and the O2 from the plants no longer has anywhere else to go, so it bubbles off.
While staring at my tank last night, having previously just gassed my fish and had to carry out an emergency water change, I had this idea of why all our plants pearl much more in the 12 hours after water changing.. see what you think, its just a theory, and might be full of holes.
Pearling happens when the plant is producing more O2 than can be effectively dissolved into the water column.
When we add fresh water, the water we put in is pretty super-saturated with O2.. so could it be, that under the minimal pressure of a fish tank, the saturation levels are just too high in the water to accept any more O2 from the plants?
Using my scuba knowledge about partial pressure and gas theory, to super-saturate a liquid with a gas, a higher partial pressure can be achieved by putting the liquid under pressure, much like a soda bottle.. when you release the pressure on the soda bottle, the gas (in this case co2) come out of solution and turns back into the gas phase. This is what happens when a diver comes up to fast, and nitrogen comes out of solution inside his/her body, causing micro bubbles in the nervous system.
Could this be whats happening when weve added fresh o2 laden water? The partial pressure of the O2 is purely to high to accept new gas from the plants.. so it remains out of solution as bubbles...
so.. if this is correct.. the excess pearling we see when weve carried out a water change, isnt actually a growth spurt, its purely o2 with nowhere else to go.
With no o2 measuring equipment i cant test this theory.. although it stands up on paper.
This would also explain why it takes a short while for the plants to start pearling when lights go on. The O2 levels in the water would have stabalised over night with no fresh addition of O2 from the plants (surface movement cant super-saturate).. after a few hours, the O2 levels rise to capacity, and the O2 from the plants no longer has anywhere else to go, so it bubbles off.
