What Pond Dye Can Add to Your Pond
Pond dye is most often used to enhance the color of your pond, whether you use bright or dark shades of blue, blue-green, or even black. If your water is starting to look cloudy and unattractive, pond dye can “hide the blemishes.” But besides the aesthetic appeal of pond dye, it also can reduce the sun’s exposure and limit the growth of algae. This is because pond dye can block parts of the solar spectrum, slowing growth and creating a cleaner pond environment. Also, pond dyes can protect your fish from predators flying from above, as the dye helps to prevent birds from seeing through the water. During summer months, pond dye can keep your water cooler and allow fish more oxygen to breathe.
You Choose a Color
The color choice is largely up to you. In most cases it depends on your personal preference. Brown and grayish water can be transformed into a mirrored surface with black pond dyes, reflecting trees and boulders onto the pond’s surface. The mirrored surface can be mesmerizing when the light is right. Blue dyes are probably the most popular, as they are pretty to look at and contrast well with green landscapes surrounding a pond. 
How to Apply the Dye
You should wear gloves during application, whether you use liquid dye or packets. You can spread around the shoreline or take out a boat to the deepest spot and spread it out there, using an oar to push it around a bit. Eventually, the dye should spread out to the entire pond.
But in order to know how much to use, you will need to know either your pond’s total estimated gallons of water or acre feet of volume. You’ll need to estimate your pond’s average depth, typically by taking measurements at different points in the pond. You can take out a boat and drop a weighted line into the water at various spots in your pond. And of course you will need an estimate of your pond’s length and width. Then you can use our pond size calculator to determine both acre feet and total gallons of water.
If it’s your first time using pond dye, then add dye in small amounts at a time until you find the color you’re looking for. Make a note of how much you used so that next time you’ll know how much dye it takes.
You’ll need to reapply dye every 4 to 8 weeks, depending on rain.
But Is It Safe?
Pond dye is safe for fish, wildlife, birds, horses, and humans, though it is not recommended if you use a pond for drinking water.
However, in its concentrated form, it can stain clothing and skin, so it is best to wear gloves and work clothes when applying. After the dye has been in the pond for 24 hours or so, it should be diluted and no longer stain.
More on Pond Dyes
Ponds often undergo algae blooms during the spring and fall, when ponds are stirred by changes in temperature and wind conditions. Organic bottom sediments create fresh nutrients, which can create a murky green or brownish look to the pond. If nutrients keep being added to the pond from the wind or other sources. If possible, prevent more nutrients from entering the pond by creating barriers to them. But pond dyes, as discussed above, prevent photosynthesis from occurring by creating a shade. Sunlight has a more difficult time penetrating.
You Might Also Want to Add an Aerator
At the same time, you can prevent unwanted weeds from growing by adding an aerator of some kind. You can add a surface aerator (or a bottom aerator if your pond has an average depth of seven or eight feet or more). The surface aerator floats on the surface and the pump is suspended by a float. The pump normally has a very long cord so that it can hang down to the bottom of the pond and then be plugged in at the shoreline. These are quite safe as long as you use a GFCI outlet, though swimmers should not be in a pond where a pump is running. Bottom aerators use a diffuser system which provides air bubbles similar to what you see in an aquarium. An air compressor pumps air from a location on the shore through tubing that emits air through the diffusers.
Final Thoughts
All in all, pond dye can be beneficial in more ways than beauty. It can provide the shade to cut down on the growth of algae. The addition of a pond fountain or other form of aeration can also provide for a more healthy pond. It can decrease sun exposure and provide a balanced and healthy pond, decreasing unwanted algae, muck, and protecting your fish.