How to Get Rid of Leeches in Lakes and Ponds (Without Freaking Out!)

Alright, so you’re dealing with leeches in your pond or lake—those creepy, blood-sucking little critters that make your skin crawl just thinking about them. Don’t worry, you’re not alone. These slimy parasites are annoying, but there are ways to get rid of them without turning your pond into a horror movie set.

Spoiler alert: You don’t have to drain the lake or avoid swimming forever. Let’s break it down step by step… 

No panicking allowed, this is as easy as 1 2 3...

Step 1: First Things First, Make Sure The offensive Organisms are Leeches

If you’ve never encountered a leech before, they look a little like this:

The common aquatic leech is a parasitic segmented worm. These wriggly critters are native to just about everywhere and are NOT (generally) indicators of a degraded aquatic resource. Most of the time they are black, sometimes they have a stripe, and still other times you can see an interesting mottled pattern to liven things up a bit. They are active swimmers, but will mostly hang out at the bottom of your lake/pond or in the weeds, waiting for an unsuspecting human or fish to wander on by.

These vampires of the depths feed on blood and do not discriminate in hosts. If your water body has an abundance of leeches, you will probably know about it if you spend enough time wading around in the shallows. 

Before you start the “Leech Apocalypse” (sounds cool, right?), make sure you actually have a leech problem. Here’s how to know if leeches are lurking in your pond:

• Look for them: Leeches love to hang out in shallow, murky areas, like the creepy villains they are. Check the water’s edge.
• Swimming wounds: If you or your friends come out of the water with small, circular bite marks (gross, I know), you’ve got leeches.
• Bait test: Take some raw meat, toss it into the water, and see if leeches show up for a snack. If they do, it’s game on.

Not all leech-containing waters are in trouble, some are just unlucky. An overabundance of leeches IS an indicator of a resource that has been poorly managed or contains an underlying condition that lends itself to ecological imbalance.

Step 2: Build a Leech Trap (Yes, You Can DIY This!)

This is probably the easiest and cheapest way to start. It’s like fishing but instead of catching bass, you’re trapping slimy, bloodsucking critters. And guess what? It’s oddly satisfying!

Here’s how you do it:

How to set it up:

1. Put a small piece of raw meat in the can (yum, right?).
2. Punch some holes in the lid or side of the can.
3. Drop it in the shallow areas of your pond where leeches love to hang out.
4. Leave it overnight (think of it like leech room service).
5. In the morning, surprise! The can will be full of leeches. Dispose of them far away from the pond, so they can’t make a comeback.

Repeat the process for a few nights, and soon you’ll notice fewer leeches swimming around.

Step 3: Unleash the Fish Army

Leeches may be a terror to you, but to some fish, they’re just a snack. Introducing fish that eat leeches is like hiring an all-you-can-eat buffet crew to keep your pond clean. This is the simplest and easiest solution to a leech issue. Leeches are a high-value prey item for most game fish.

Fish that LOVE to eat leeches:

• Sunfish (Bluegills, Bream, Pumpkinseed, Redear, etc)
• Bass

Just about any fish that is large enough to fit a leech in its mouth will gladly consume them. 

Throw a few of these bad boys into your pond, and they’ll naturally keep the leech population down. Plus, having some extra fish in your pond makes it feel more lively (and less like a leech-infested horror zone). A stable fishery is a major part of a balanced ecosystem, Mother Nature gave us fish for a reason - they are a vital cog in the gears of the nutrient cycle. 

Step 4: Clean Up the Pond (Because Leeches Love Mess)

Leeches love hiding in muck, debris, and vegetation. The messier your pond, the more they’ll stick around. So, do a little cleaning:

• Remove leaves, twigs, and dead plants from the pond’s edges.
• Specifically in areas where you access the water (beaches & docks/piers)
• Start using organic muck digesting Pond bacteria to chew up leech habitat and kick-start the bottom of your pond's food chain. Here are some good products that I use:
• Superior Pond: Eco-Block
• Easy Pro: Sludge Remover Bacteria
• Clear Lake: Muck Eliminator
• Trim overgrown vegetation where leeches like to hide.
• Messy trees like willows contribute literally TONS of debris to your pond every year. If you can remove or prune back willows away from the pond’s edge
• Add a fountain or aerator to keep the water moving. Leeches love still water, but they hate when things get bubbly and active. Pond Aeration is NEVER a bad thing. Supercharging your pond ecosystem helps in numerous ways.
• Here are a few easy DIY Pond Aerator kits/devices for your perusal:
• Pond Fountains
• Surface Aerators
• Diffused Aeration Kits

(Need more info on pond aerators? Please read this article on the 3 Types of pond aeration: Which is best for your pond?)

Turn your pond into a leech-hostile zone. A clean, well-circulated pond is no place for these freeloaders. Stocking fish and having a good aerator should keep your leech issue at bay.

Step 5: When All Else Fails, Salt ‘Em (Carefully)

If you’re looking for the nuclear option, salt can be a leech’s worst enemy. Here’s the deal though: you can’t just dump salt into the pond like you’re seasoning a giant soup—too much can harm plants and fish.

But, for small areas where leeches are heavily concentrated (like the edges of the pond), a little bit of salt can do the trick. Just sprinkle it around carefully. You could even use a saltwater solution in specific spots to clear out leeches.

SPECIAL BIOLOGICAL NOTE: Koi can handle a fair bit of salt in the water column. In fact, a slightly briny pond helps them develop their slime coat which is a vital part of their immune system. It acts as a barrier to pathogens and parasites. How much salt did you ask? Ideally. Between 0.1%-0.3% or 1000-3000 PPM.

Step 6: Prevent Future Leeches

Once you've dealt with the leech invasion, you’ll want to keep it that way. Here’s how to prevent them from returning:

• Keep the pond clean and debris-free.
• Maintain water circulation with a fountain or aerator (leeches hate the movement).
• Stockfish that love to eat leeches and keep them in check naturally.

A Quick Recap (Because Leech Prevention is Key):

Final Thoughts: The Great Leech Battle

Dealing with leeches might seem like a nightmare, but it’s totally manageable if you follow these simple steps. Just remember, you don’t need to go full-on "monster hunter." Start with the leech traps and let your new fishy friends help out. Keep your pond clean, and soon enough, leeches will be a thing of the past.

As the saying goes, “An ounce of prevention is worth a pound of cure.” So, keep that pond leech-free and enjoy your time on the water—minus the creepy crawlers!

Good luck, and may your lake or pond become a leech-free paradise!