It is important to monitor your water quality throughout the year every year. By doing so you will notice trends and it may help you see an arising problem before it becomes a severe problem that may cause a fish kill resulting in a lot of costs to fix. Three factors, alkalinity, hardness and pH, may be pretty confusing to understand for some but more importantly difficult for the average person to sample. However with the right equipment and a little learning you can take these samples yourself as well. You want to see your waters alkalinity between 20-150 ppm. However if it falls below 20 ppm your ponds ability to grow fish is greatly diminished. This indicates that all the minerals needed to develop properly are not available.
You can buy test strips to test your waters pH on your own. If your waters pH is 6-8 I would not worry about anything. However if it starts getting to 5 or below you have an issue, the same goes for if it gets too much above 8. Outside of those parameters there will begin to be a great deal of stress on your fish just trying to stay alive. You may need to add lime to your water to bring it back to that happy medium. These next two parameters are a little easier to understand and sample yourself at home.
Water color and turbidity are important measure to look at. When it comes to fish production you would ideally like your water to have some shade of green to it. This indicates that there is phytoplankton blooms happening which is the basis of the food chain and is ideal for fish production. If the water is shaded brown or white looking the turbidity is caused by suspended soil particles, most likely clay. This is undesirable because that will prevent phytoplankton blooms hindering fish production. This leads us into the water turbidity.
For ideal fish production you want to have a depth of view, usually measured with a secchi disk, to be between 18-24 inches. If the water is too turbid from too much phytoplankton there may be a shortage of dissolved oxygen in the water after awhile, stressing the fish. However if it is due to soil particles, light cannot enter the water column to entice phytoplankton growth limiting productivity. This can also cause low dissolved oxygen levels because aquatic plants cannot get enough light for photosynthesis. However if the water is too clear, depth readings greater than 24 inches, the phytoplankton productivity is inadequate for proper fish growth and you run the risk of problems with aquatic plants taking over the pond bottom.
Finally this brings me to dissolved oxygen content. You can buy meters to check your dissolved oxygen or have a biologist come do it for you. Dissolved oxygen will be lowest in the mornings due to lack of photosynthesis overnight. Ideally you want dissolved oxygen to be at or above 5mg/L, in fact some studies show that largemouth bass growth is best with about 8mg/L. Fish growth will slow and there will be a higher risk of disease if the concentration falls between 2-5mg/L and anything less than 2mg/L becomes lethal and a fish kill is likely. Some signs that your waters dissolved oxygen may be dwindling is if your water begins to stink like rotten eggs and if you are seeing fish at the surface gasping for air. In both situations the outcome is likely not good.
Although it is tough to understand water quality is the number one limiting factor to having a successful fishing pond. Watch and monitor your water closely to observe any potential changes. The more records you keep and the longer you keep them, the more likely you may see a problem arising before it becomes a serious issue and it may be able to be corrected with minimal expenses.
Manage today for a better tomorrow!
Brett Kleinschmit