Guppy Grass: Friend or Foe?

​Najas Guadalupensis,
also known as Najas grass,
​aka Guppy Grass.
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The Good

​This fast-growing plant, which can grow rooted or floating, is named for its ability to provide baby guppies with plenty of hiding places when born. It’s also great at removing toxins from water. As is the case with most fast-growing plants, it is exceptional at taking up nutrients in the form of heavy metals, toxins, ammonia, nitrite, and nitrates from water. It consumes almost every free nutrient in the water leaving little behind for algae growth. As great as that sounds, don’t run out and plant your water garden up with Guppy Grass until you understand its growth habits.
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The Bad

In our experience, it grows faster than algae, which can cause some inconvenient problems if not constantly removed from your stream.  It spreads throughout small ponds like a wildfire and once it is completely rooted throughout your stream, it has the ability to displace most of the water in your shallow babbling brook in just a couple of weeks, which means if you don’t “mow” it to the stones every week, you are in for some displacement leaks.
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How did guppy grass get into my pond?  I didn’t plant it there!

Guppy grass is native to the Americas, from Canada to southern Mexico. It is an extremely popular plant in the aquarium hobby. So, basically, it’s everywhere. It’s commonly found in golf course ponds and backyard ponds that do not have circulation systems, largely due to its amazing ability to sponge impurities from the water. It only takes an inch of plant to start a new plant. So, a one-inch piece of plant can hitchhike its way to your pond on a bird that visited a golf course pond just before it stopped off at your pond.  We have seen this several times now.
If you have a golf course pond nearby (as so many of us do here in the Valley of the Sun), keep a watchful eye on your pond for any new and unknown plants showing up. The most likely place for you to see the Guppy Grass first is in your stream bed.  If you should see it, carefully remove ALL of it immediately.  It doesn’t take long for it to get a foothold and once established, it is virtually impossible to remove without a complete cleanout, and dry-out, of your organic water garden.  In short, it is rarely worth the effort.
That’s not to say that there is never a time Guppy Grass is a good idea. However, if you have a longish gravel stream bed, Guppy Grass presents a higher maintenance issue than filamentous algae.

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What do I do about Guppy Grass?

Please check with your Pond Gnome Pond Pro to see if Guppy Grass is right for your pond!
Pros

• Provides great habitat for guppies and invertebrates to hide from predators.
• Removes toxins and nutrients from the water in large quantities

Cons

• Grows like wildfire!
• Impossible to remove from an established eco system pond once established

The Pond Gnome does not recommend introducing Guppy Grass to your Pond Gnome water garden.

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OTHER POSTS YOU MIGHT LIKE:
WETLANDS: THE WHAT, WHY AND WHERE
WHY YOUR PLANTS CAN SUFFOCATE YOUR FISH
PH FOR PHOENIX PONDS

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