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Can You Trim Frogbit Roots?

The popularity of using frogbit in both aquariums and ponds is continuing to grow in popularity with more and more people reaching out and asking various questions about frogbit as its popularity continues to increase.

As we covered in our duckweed vs frogbit comparison article, frogbit is an excellent live plant to have in your aquarium or pond but it does require some level of maintenance to keep the frogbit roots in check due to how fast and long they can grow.

This is why we see so many people reaching out with various questions about trimming frogbit roots each month so we decided to make our own article dedicated to the topic.

Many people choose frogbit as their surface plant of choice due to it looking more like a mini water lily leaf but the trade-off is that once or twice per month, you will have to trim its roots.

If you don’t have the time to trim the roots of your frogbit then you should probably consider duckweed instead.

We actually see a range of different questions being asked from the fish keeping community about frogbit roots so we have decided to include as many of these questions as possible in this single article.

Our hope is that we will be able to help as many of our readers as possible by including all the information that you require about frogbit roots and our table of contents below is able to help you navigate the article quickly.

Does Frogbit Have Long Roots?

Frogbit can have very long roots that will just keep growing and growing unless you trim them.

The optimal water parameters, frogbit can easily grow its roots from around one inch to around six inches in four weeks with additional growth being common in some tanks depending on water parameters.

As you may be able to guess, the longer your frogbit roots get the more problems they will cause. Not only will they tangle on the decorations of your aquarium or pond but they also blog out a large amount of light too.

This can cause issues with your submerged live plants not being able to get all of the light that they need to grow correctly and result in issues with oxygen levels in your tank.

On top of this, if you have some skittish fish species that are easily scared in your tank, the long frogbit roots can end up causing stress and anxiety in some fish as it constantly brushes against your fish.

This is why the majority of people who keep frogbit will cut its roots down once or twice per month to prevent these issues from occurring in their tanks.

“Frogbit – Hydrocharis morsus-ranae” by Jeremy Halls is licensed under CC BY-SA 2.0. To view a copy of this license, visit

Is It Ok To Trim Frogbit Roots?

It is fine to trim frogbit roots down but you will usually have to keep their roots around an inch long to ensure that the frogbit is still able to draw nutrients from the water.

Some people do trim their frogbit roots down to around half an inch in length but this can cause problems with the frogbit not being able to draw nutrients from the water so we usually recommend you keep one full inch of root length when trimming it down.

There is no need to use fancy tools when trimming your frogbit roots either with the majority of people simply using No products found..

This allows you to quickly and easily cut the roots of your frogbit down to size without having to waste time on maintaining the frogbit growing in your aquarium or pond.

Scissors tend to offer a nice clean cut on the roots too making it easier for them to continue to grow without issue.

We have seen some people using unsuitable tools to trim their frog bit roots that can rip and tear them causing problems with the root being able to absorb nutrients from the water and the frogbit having problems.

Recommended Frogbit Root Length!

We usually recommend that you trim your frogbit roots down to around an inch in length.

This tends to offer the best blend of trimming the roots down to allow light to get into your tank while also leaving enough length on the roots to allow the plants to absorb nutrients from your water.

As we covered in our article on how to stop your frogbit dying, cutting the roots of your frogbit too short is a common problem and although some people will cut the roots of their frogbit as short as half an inch, we don’t recommend it.

Not only does this make it difficult for the frogbit to absorb nutrients from the water but the shorter the roots of the frogbit, the more likely it is that the fish in your aquarium or pond will eat it in large amounts too.

We have seen people on social media recommending that you apply root growth inhibitor sprays on your frogbit roots after cutting them but we would never recommend this.

These sprays have a large number of different chemicals in them and they will cause problems with your water parameters so if you don’t have the time to trim your frogbit roots, just go with duckweed instead.

How Often Should You Trim Frogbit Roots?

The majority of people will usually trim their frogbit roots once or twice per month depending on how quickly the roots of their frogbit grow.

In some aquariums and ponds, the water parameters will allow to frogbit roots to grow at a rapid pace and you may have to trim the roots three or even four times a month depending on your situation.

This is somewhat of a pain for many people as they have to work the trimming of their frogbit roots into their regular tank maintenance too. If you have a larger aquarium or pond then simply trimming the roots of your frogbit can add a surprising amount of work to your maintenance tasks.

This is why we feel that many people are often better off just going with duckweed over frogbit as it doesn’t require as much maintenance and helps to free up your time.

It will usually come down to your own personal preferences though depending on your situation and the goals you have for your aquarium or pond.


That brings our article going over trimming frogbit roots to an end. We hope that we have been able to help you better understand what you should be doing with your frogbit roots and that it is perfectly fine to trim the roots down when needed. It is very common and the vast majority of people who keep frogbit in their aquariums or ponds will regularly trim the roots of their frogbit down to keep them around the one inch length when possible.