There are many things to consider in deciding to fertilize your pond. Do you want to grow bigger fish? Do your want to catch fish when you do go fishing? Do you want your pond to look good? A fertilized pond can produce three to four times as many pounds of fish per acre each year than a non-fertilized pond. A well-managed pond will usually produce 300 to 500 pounds more fish per acre each year. With a fertilized pond, you have more fish and your fish will have more to eat; in return you have bigger fish to catch. It takes very little time or money to have a good fertilized pond or lake. The secret is knowing what to do, how to do it, when to do it and why you are doing it. Why is simple to answer -  to grow bigger fish, to catch more fish and to have a better time fishing. You have spent probably thousands of dollars in building a pond and now you want to enjoy it, so fertilize it.

Pond fertilizers are available in liquid, granular, or powdered forms. All of them are good. Consider your preferences to find the one that’s right for you. Liquid is heavier than water and will have to be diluted before it can be applied. Some times special equipment is needed to apply this liquid fertilizer.  Large lakes require you to apply over a larger area, boat and spray equipment should be used. First if your pond is small you will have to shake up the liquid to get it to mixed properly. If all is not used, then dilute it. You should dilute liquid fertilizer;  three gallons of water for one gallon of liquid fertilizer needed and apply with a sprayer. Try to apply as much as you can evenly over your pond. Liquid takes more time to apply and it might not be to your advantage to use that type. But it does act a littler quicker than granular fertilizer. The liquid does cost a little more to use. Granular fertilizer is a little less expensive but it will have to be kept off the mud. This is very important. You will have to put something under the granular, to keep off the mud. You can use visqueen or any kind of plastic or a platform. For every 3-5 surface acres of water you would need a location to apply your granular. You need to place the granular fertilizer in about 3-6 inches of water near the pond bank. Do not take you granular and broadcast it into the water or pour it behind you boat. If you do that, you just wasted your money. Power fertilizer should be used as the instructions say. There are several different kinds of power fertilizer.  What little I have used has not work in my commercial operation. But some of my clients like the powder and it works well for them, so you might try it. 

Liming is the key. It is so important that if you need lime you have to use it.  Get help. Contact your County Extension Agent, your local Soil Conservationist, or your State Universities Aquaculture Department. Get a soil sample from the pond and get it tested. This is a must. If you need lime and don’t get it you will never have good pond.  I cannot over emphasize the importance of lime to your pond’s water quality. It’s the key to unlocking everything in the pond. Lime is going to make your fertilizer work and be more effective. If unsure of your need for lime, get help. 

Begin fertilization in the spring when water temperatures have stabilized at 60 degrees Fahrenheit.  Then stop when water temperatures cool down to 60 degrees in the fall. A simple method of knowing when to fertilizer is to examine your water clarity. If the sunlight penetrates the water 18 inches or more, a fertilization program should be implemented. The depth of light penetrating into the pond is a measurement of algae density or bloom. Once a program is started, it needs to be continued all summer.  General instructions to fertilize.

After fertilizing, pond water will turn a light green color. The reason for this color change is plankton growth. Plankton is presence when the water is filled with tiny plants and animals, called plankton.  A good bloom is light green water, dark enough where you cannot see more than 12-18 inches deep. A good fertilization program will keep the water a light green color all summer long. Fertilizer will turn water light green in color with plankton. Water insects and other organisms use the plankton for food. Small fish feed on these insects and organisms. When plankton production is increased with fertilizer, fish production also increases. Fertilizer can be applied to stimulate plankton growth and increase fish production in all ponds. 

No two ponds are alike, and with our present knowledge, it is impossible to predict the rate of fertilizer to use in everyone’s pond or lake. The types of soil in your pond will determine the amount of fertilizer you will need. Try these rates for the various types and find out what works best for you. 
Liquid fertilizers include 10-34-0 and 13-37-0 or 13-38-0.  The key ingredient is phosphorous (middle number). Try one gallon per surface acre and wait 7 days for a bloom. If no bloom add one quart every 7 days until you get a bloom.
A granular fertilizer such as Triple Super Phosphate (0-46-0) is the most economical. Try 12 pounds per surface acre.  Wait 7 days and if no bloom appears, add 10 pounds a week until you get a bloom.
Another granular fertilizer is 0-20-0. Use twice the amount recommended for 0-46-0. Try 24 pounds per surface acre and wait 7 days.  If there is no bloom, add 20 pounds a week until you get a bloom.
16-20-5  is also a granular fertilizer that can be used. You would need about 40 pounds per surface acre of this type. If there is not a bloom within 7 days after application, add 20 pounds per week until the water turns light green in color.
18-46-0 is a good granular fertilizer that requires about 18 pounds per surface acre. Wait seven days and check for a bloom. If there is not a bloom, add 9 pounds per week until the bloom appears.