Use a thermometer to measure the
surface water temperature of the pond. The water temperature at the deepest
part of the pond can be measured using a thermometer attached to a weighted
rope. Lower the device until it is just off the bottom and leave it suspended
there for approximately 5 minutes. Raise the device quickly through the
water column, remove the thermometer and check the temperature immediately.
Thermometers can be purchased from local hardware stores, aquarium shops,
equipment supply companies.
There are several ways to estimate the volume of your pond. Generally, the following calculations will give you a reasonable estimate of the number of gallons in your pond.
If you have rectangular pond:
Length x Width
x Average Depth (see above)= ___ft cubed
3.14 x radius of your pond squared x average depth = ___ft cubed
Use the same conversion from cubic feet to gallons:
ft cubed / 0.134 ft cubed per gallon = ___gal
If your pond basin in mostly conical in shape you can use the formula for the volume of a cone:
1.047 x radius squared x maximum depth = ___ft cubed
Water clarity can be influenced by many variables such as turbidity of sediments and algal density in pond ecosystems. Monitoring the water clarity in your pond can be very interesting over the course of the year. Besides qualitative methods which are informative, the standard method for measuring water transparency is to use a secchi disk. Secchi disks are available for purchase from various equipment supply companies.