Some winter O2 and temp readings - 02/03/19 07:34 PM
O2 and temp readings were taken with a YSI ODO meter. The probe was left at that depth and slightly moved until the readings stabilized.
This pond is approximately 5/8 to ¾ surface acre at this time, and the winter diffuser is placed in 9 to 10 feet of water but the actual diffuser is only 2 to 3 feet below the water surface. The open water hole is approximately 40 feet in diameter. The deepest part of the pond at this time is 14 feet.
The diffuser was turned on and off during the last cold spell to keep an open area. The last time the diffuser was on was from 48 to 36 hours ago. Since then the temps have climbed from 10°F to the mid 40's. During the past 24 hr our cloud cover has been pretty heavy with 75%-80% of our 8" of snow cover melting since yesterday morning. There was approximately 8” of snow on top of 2” of cloudy ice and there is 3”-4” of clear ice under that for a total of 6” ice.
Reading #1, is approximately 40'-50' from the diffuser. There was 4" to 5" of ice there and since it was approximately 20' from the diffuser open water I didn't want to chance getting any closer. The total water column depth at this location is 9 feet at this time.
Water depth Temp DO (in mg/l)
2 feet 34.7°F 9.15
4 feet 34.9°F 9.03
6 feet 35.2°F 8.58
8 feet 35.6°F 8.02
Reading #2, in the deepest part of the pond, This location approximately 180 feet from the diffuser and 160 feet from the open water.
Water Depth Temp Do (in mg/l)
2 feet 34.8°F 9.01
4 feet 34.9°F 8.77
6 feet 35.3°F 8.55
8 feet 35.9°F 7.40
10 feet 37.1°F 5.63
12 feet 37.1°F 5.60
13 feet 37.1° 5.60
So, the further away from the winter diffuser, the less O2 there is. That’s why I recommend a minimum of 5% of the total pond surface be exposed to the air for the winter to prevent a winterkill.
This pond is approximately 5/8 to ¾ surface acre at this time, and the winter diffuser is placed in 9 to 10 feet of water but the actual diffuser is only 2 to 3 feet below the water surface. The open water hole is approximately 40 feet in diameter. The deepest part of the pond at this time is 14 feet.
The diffuser was turned on and off during the last cold spell to keep an open area. The last time the diffuser was on was from 48 to 36 hours ago. Since then the temps have climbed from 10°F to the mid 40's. During the past 24 hr our cloud cover has been pretty heavy with 75%-80% of our 8" of snow cover melting since yesterday morning. There was approximately 8” of snow on top of 2” of cloudy ice and there is 3”-4” of clear ice under that for a total of 6” ice.
Reading #1, is approximately 40'-50' from the diffuser. There was 4" to 5" of ice there and since it was approximately 20' from the diffuser open water I didn't want to chance getting any closer. The total water column depth at this location is 9 feet at this time.
Water depth Temp DO (in mg/l)
2 feet 34.7°F 9.15
4 feet 34.9°F 9.03
6 feet 35.2°F 8.58
8 feet 35.6°F 8.02
Reading #2, in the deepest part of the pond, This location approximately 180 feet from the diffuser and 160 feet from the open water.
Water Depth Temp Do (in mg/l)
2 feet 34.8°F 9.01
4 feet 34.9°F 8.77
6 feet 35.3°F 8.55
8 feet 35.9°F 7.40
10 feet 37.1°F 5.63
12 feet 37.1°F 5.60
13 feet 37.1° 5.60
So, the further away from the winter diffuser, the less O2 there is. That’s why I recommend a minimum of 5% of the total pond surface be exposed to the air for the winter to prevent a winterkill.
