Jpsdad - The ice dome is a closed system. As the dome increases in size (the ice lifts farther and farther off the water) it actually increases the PSI on my pump. The air from the plume does not contact the outside atmosphere - it only contacts the air trapped under the dome. What I am asking is this, wouldn't the air trapped under the dome run out of O2 to exchange?
Thank you for clarifying. I am just sitting thinking ...
It seems to me that if the air pump is able to move air that goes through the diffusers then new air is going into the system all of the time. Now I don't know what cfm your air pump can generate but you are at least putting the air fully charged with oxygen into the pond at that rate. There is ~.08 lbs of O2 in every cubit ft (@ sea level) ... 10,000 feet it would be less. For now lets assume .06 lbs of O2 per cu ft. So at 10 cfm there would be 864 lbs of O2 entering the pond every day via the pump. To be sure, the water doesn't dissolve all of it but as far as a lack of O2 in the dome ... no ... I think the difference in O2 there and the atmosphere is likely small where the difference is caused by oxygen dissolving into the water. There must be cracks or a spill point that lets the air out, If no air leaks out, then every ounce of it is dissolved into the water, and so I think it more plausible that it leaks out of the dome some how. I don't know what cfm is being pumped or what percentage of the oxygen is dissolved but I think it is clear that only a fraction of 10 cfm would need to be dissolved to support the fish. DO will dissolve mostly at the interface of the dome air and water surface.
The trout grow even more in the summer than the winter. When we have stocked fish in late June or early July they have usually doubled or almost doubled by late September. I don't necessarily think the fatheads or scuds NEED a refuge. They survived every year before there was ever any aeration.
It would be normal for growth to be greatest during the summer.
I wasn't for sure exactly what you meant by doubling. Whether it be weight or length. If length is doubled, the weight is more than octupled. Either way, the growth of your trout in winter seems extraordinary to me and I think an explanation like "The prey is dispersed throughout the lake and the trout are greatly deprived of oxygen" falls short of explaining this extraordinary growth. Like you, I am seeking answers but the ones I postulated are the only ones that I am comfortable with.
