Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Where did my fish go? DO problem?

Re: Geo systems. Unless you have a whole house humidifier, the lower humidity in the house during the winter makes a HUGE difference in the "feels like" temp. I can run my pellet stove and keep the house at 69°F - 70°F and the house feels cold with relative humidity levels in the mid 20% range. I can turn on the forced air propane fueled furnace to keep the house at the same temp along with a whole house humidifier that is added onto the forced air furnace. The house feels comfortable at 70°F with a long sleeve t-shirt on.

The other house has a wood burning insert and can heat the house to whatever temp I want. As a test one winter I had it 100°F over ambient temp (-20°F outside). I can run 3 ultrasonic humidifiers in that house, putting 6 gallons of water into the air and I cannot get the humidity over 20% there. The house also has a natural gas forced air furnace, but there is no whole house humidifier installed on it, so the house needs to be 74°F-75°F to feel the same comfort level as 70°F in this house. That house is built on a crawlspace, and the floor is not insulated - so there is more outside air moving in and out of the house.

A customer that is local here has an open loop geothermal system. Our ground water is 53°F - 54°F. the system dumps into his pond. His system needs propane back-up in the coldest part of the winter. He has a separate whole house humidifier built into the forced air A/C system that keeps the humidity in the house where it feels comfortable.

What is the Relative Humidity in your house this winter?

For the winter with your in-the-pond geothermal system, fresh water is the densest at 39°F. So you should be seeing 39°F water at the bottom of the pond. That 39°F water sinks to the bottom of the pond and water that is colder than that OR warmer than that will come to the surface. I am assuming that your temps are a wee bit lower due to the geothermal system sucking some heat energy out of the water. In my pond, since I have a groundwater pond and water moves through the pond as it moves through the ground, my deepest pond water temps usually are around 40°F., even with the aeration system running.

Since the winter aeration system is not designed to disrupt the lower denser, therefore, warmer water, it shouldn't have much effect on your geothermal system. A properly places winter aeration system might affect water temp down to 6'-8' because the diffuser should be placed at 1/4 to maybe 1/3 the total pond depth, close enough to the shore that anything that might go swimming can get to shore to get out. I would go talk with the geothermal people in regards to your water temp in the pond to see what a degree or two of change might mean to the geothermal system.

At what water depth are the coils placed in the pond? Can you take a temp reading within a foot of those coils? That might help you when you talk to the geothermal people.

I learned that using a fish finder while ice fishing made a HUGE difference in figuring out where the fish were. They don't have to bite to be seen. I can also see the zooplankton/copepods/daphnia on the screen. It shows up close to the pond bottom, but as the light levels diminish (at sunset) I can see it rise up off the bottom and move towards the surface of the pond (following the sunlight). A few weeks ago I caught crappie and bluegills 2' under the ice.

The only way you will know for sure about the YP and SMB is to fish for them when the water temp is in the mid to upper 60's once the ice is gone.

I agree with Ron in asking what the alkalinity of the pond is? A simple test strip should tell you that, and it might also tell you what the pH is in the pond too.