When to fertilize and apply lime

This topic is pretty complex, but I'll hit the high spots.

You only need to lime if your pond's alkalinity levels fall below 20 ppm. Actually, 15 ppm is probably the threshold where benefits from liming outweigh the costs. If you don't have the capability of testing your alkalinity, a call to your state fisheries biologist or extension agent could tell you if alkalinity levels are typically high or low in your area. If lime is required, a typical rate would be 3 tons/acre. Virtually all of the cost is due to transport and application, as agricultural lime is only a few dollars per ton.

Water temperature should exceed 60 F before fertilizer is applied. In the south this occurs in March. You can use any fertilizer that is high in phosphorous, but application rates and methods vary depending on whether it is liquid, granular (slow dissove), or powder (quick dissolve). Two applications, three weeks apart, is the minimum for establishing a bloom. A third application is often required after an additional three weeks. After that app, wait for the bloom. Don't be tempted to add additional fertilizer or you will regret it. When the initial bloom begins to wane, hit it again. Continue until water temperatures cool into the 60's.

I use 10-34-0 or 11-37-0 liquid, which is pretty cheap. First application is 2 gal/acre, with subsequent apps at 1 gal/acre. For lakes larger than about 2 acres, mix 10:1 with water and apply to the entire surface. I use a stock tank and electric bilge pump or small gas pump when applying from a boat. For smaller lakes, mixing 10:1 with water in a stock tank and applying with a gas pump/spray nozzle combo works great. Others have used small pump-up sprayers without dilution effectively.

You can begin fertilization as late as mid-summer if you want, but DON'T add fertilizer to a lake already infested with aquatic vegetation that has reached the surface. :rolleyes: