Should you fertilize your pond?
It’s the age-old question…should you fertilize your pond? I get this question a lot, especially when the weather is halfway acting like it wants to get warmer. That question is usually met with a possibly unsatisfactory answer which is it depends. It depends because there are several factors that must be evaluated before determining whether or not you actually need to fertilize or not. However, what does fertilizer actually do for a pond?
What fertilizer does not do is directly make your fish grow larger. First, it is going to provide nutrients for any plant life you have in the pond.
Second, it is going to provide nutrients for any algae you may have growing in your pond.
This is not necessarily always good. Most importantly, fertilization will grow your planktonic population that will then serve as the beginning of the food chain for smaller fish that will eventually grow into larger fish or be eaten by larger fish.
Therefore, do you need to fertilize or do you have adequate planktonic populations to support the fish you have already? The clarity of the water is going to serve as a major indicator of whether you need to fertilize or not. Utilizing a Secchi disk will not only let you know if you need to fertilize depending on the depth at which you can see the disk, but it can also let you know if you have too many nutrients that will rob the water of oxygen and potentially cause a fish kill or restrict sunlight that can cause oxygen depletion and potentially cause a fish kill. Another thing to consider is how much water is draining out of the pond. If you have a considerable amount of water draining then it is possible that whatever fertilizer you are applying will just end up downstream. Unlike soil, there is not a lab analysis that can indicate if or how much fertilizer is necessary for you pond.
The Extension office does test water hardness in office to determine lime needs, but that does not give an indication of the pond’s fertility. Therefore, the Secchi disk and/or water clarity may be the best indicators.
Improper fertilization can have severely negative impacts on your pond’s ecosystem as well. If your pond does require fertilization then applications should be made monthly between March and October.
Applying fertilizer once per year is not the best practice. It would be better to not fertilize at all than to just make one application because inconsistent fertilization will disrupt the forage base for bass and bream due to inconsistency.
With soils the levels of nitrogen or potassium is usually the major concern, but with ponds the emphasis is on phosphorous. The Extension office also has information on which formulation of fertilizer should be used and how much per application.
Another consideration is what are your goals for the pond? Fertilizing will increase the carrying capacity for the pond which will bring about bigger fish, but if you simply want a healthy pond then fertilization may not be right for you.
Should you fertilize your pond? It depends on your ponds natural production, do you have a major infestation of weeds that will be fed even more with fertilization, are you trying to improve the forage base of your food chain, and the questions could go on. Luckily if you have any questions about pond fertilization or other aspects of pond management then stop by the Extension office, call 478-986-3958, or email brennan4@uga.edu.
