If you are unsure of what filter, undergravel or power, is right for you, then continue reading because you've come to the right place


Each of these filters is has its own unique advantages and disadvantages, and while there is going to be a certain % of the population that may have slightly (or drastically) different circumstances, chances are the outcome is going to apply to you, too. 

Undergravel Filter vs. Power Filter - What Wins?

At least, for the vast, vast majority of users. 

The (slightly) longer reason for this: 

  •    Undergravel filters don't actually do a good job of filtering in larger tanks, or tanks with turtles, who love to kick around pieces of gravel and substrate 
  •   They are not difficult to set-up, but it is a bit laborious, as you need to set everything up before laying the substrate 
  • They need cleaned less often than power filters, but the cleaning process is a bit more wearisome 
  •   You can't use any type of rooted plants, and sometimes you might have difficulty ensuring that anything that sits on the bottom of the tank is stable 

#1 Rated Power Filter
AquaClear Power Filter

AquaClear Power Filter 3

Still not convinced? 

Here is the longer (and more complicated) explanation. 

How Undergravel Filters Work

In theory, an undergravel filter sounds awesome. 

Remembering that every filter should have 3 types of filtrations, an undergravel filter works by simply using the substrate, in this case, pieces of gravel, to act as our mechanical filtration. 

lee premium undergravel filter 2

What happens is this: 

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    Water is pulled to the bottom of the tank 
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    That water flows over and through the gravel sitting on the bottom of the tank 
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    Particles and other pieces of junk are trapped and get stuck in the gravel, ensuring that they do not circulate in the water 
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    The water that passes through the gravel is pushed or sucked back to the top of the tank and re-circulated (as well as passing through other types of filtration processes, such as chemical or biological). 

Like noted above, great in theory, right? 

Here's the problem with how this tends to actually work out in practice, however. 

  •      For starters, you need to use gravel. This type of filtration doesn't work with any other type of substrate, especially very fine particles, such as sand. The problem? Turtles will often times mistake pieces of gravel for food, and eat them.  
  •         Secondly, gravel serving as the mechanical filtration does work. Pieces of gunk and junk do get trapped around and in between the rocks. The problem? Turtles are messy, and they enjoy being messy. They often times kick up gravel and boom, suddenly your pristine, clear tank isn't looking so pristine and clean anymore after Tommy the Turtle just kicked up a bunch of poo-laden gravel.
  •        If you don't clean the gravel, the tank becomes dirty, and sometimes smelly, quickly. While you need to clean a little bit less than a regular power filter, you still need to clean. The problem is that cleaning a bunch of gravel is a lot more tiresome and taxing than cleaning a sponge out of a power filter. 

Does this mean that undergravel filters won't work for everyone? 

Of course not!

In some cases, you may opt for one instead. 

Here are some of the pros: 

undergravel filter vs power filter main
  •    Aesthetically, they look nice. Tanks are a lot nicer to look at without also noticing the (often large) gawdy-looking filters attached to their sides.
  •     By using gravel, instead of another form of filtration, this can also serve as a form of biological filtration as well.  Helpful microbial lifeforms typically build-up quickly. 
  • They are incredibly cheap. You can pick up a decent undergravel filter for less than $20 or so. 

Next, let's take a quick look at power filters. 

How Power Filters Work

If you have ever purchased one of those cheap, small aquarium sets before, it probably came with a power filter. 

It works like this: 

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    Water enters the filter through an opening (usually vented) at the bottom 
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    That water is then lifted via pump up through at least one type of filtration device (often times a sponge, can also be a cartridge of some type) 
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    The clean water is then pushed out through a spill-way on the top, out to flow throughout the rest of the tank 
AquaClear Power Filter 2

Sounds simple? 

That's because it is. 

Here is what a power filter gets right, vis-a-vis an undergravel filter 

  •    These types of filters can filter out the water and get it to a quality that is at least as good as an undergravel filter, and often times even better. 
  •     They often hang on the back or the side of the aquarium. While this is similar to undergravel filters, power filters still win out as an undergravel filter still needs to occupy space on the bottom. 
  • They can easily handle all types of filtration processes. 
  •  They are far more accessible to clean and handle, as well as being able to fit on irregularly-shaped tanks. 
  • They are nearly as inexpensive than undergravel filters. 
  • You can use them with other types of substrate, or no substrate at all. 
  • They do not affect water plant root growth. 
  •     They cannot be tampered with by your turtles. Your turtle isn't going to kick up a rock that is going to somewhere get lodged in the filter. 

Now, to be fair and objective, that doesn't mean that power filters don't have their flaws. In fact, they have a ton of flaws. 

And what are those flaws? 

  • They often need regular cleaning. At least once-a-week. 
  •          Because the spill-way hands over the bottom filter entrance, often times clean water just gets continually sucked in and cleaned, as opposed to water on the other end of the tank. That being said, these filters still can handle a lot more water volume than undergravel filters (and that water does get cleaned, eventually). 
  •      These filters usually need an open top. That means, unless your tank is well-secured, it might provide an avenue for your turtle to escape. At the very least, this contributes to increased water evaporation. 

Who Will Prefer an Undergravel Filter?

Overall, your best bet is more than likely a good power filter. 

But, (and as noted above), for some people, an undergravel filter may actually be preferable. 

In a match of undergravel filter vs. power filter, who might prefer an undergravel? 

lee premium undergravel filter 1
  •      Anyone that places the utmost priority on the tank's aesthetics. If your #1 (or near the top) priority is how your tank looks, an undergravel filter is a good option, because at the end of  the day, you can't really see it
  •      If your tank has a hood or is enclosed. Likewise, if your tank is hooded or is enclosed in any way, attaching a power filter to the side might be problematic. In this case, using an undergravel filter might be preferable. 

If you're dead set on thinking the undergravel filter is the way to go, here is an excellent recommendation. 

Best Undergravel Filter Choice: Lee's Premium Undergravel Filter

If, after reading all of this, you still believe that an undergravel filter is the way to go, you might as well go with a really quality filter. 

Lee's Premium Undergravel Filter is just that. 

It's a good, reliable filter that provides both mechanical, as well as biological filtration.

What's more: 

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    Comes in a variety of sizes, for small, medium and larger tanks 
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    Filtration unit comes with carbon cartridges, so you've got two forms of filtration already covered 
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      The bottom plate filter is relatively large, so if you've picked the right size, it should do a fairly good job of actually filtering out the junk in your tank 
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    Fairly inexpensive and decent value for the money 
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    Can be easily combined with power filters for an excellent combo filter system
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    Rated 4.3 out of 5 stars, with 66% of consumers giving it a 5-star rating 

Lee's Premium Undergravel Filter

lee premium undergravel filter 1

On the down side, you'll have to make sure that you measure your tank and get the right size, or else it won't fit laying on the bottom of your tank. 

And if the undergravel filter just won't do, you might as well good an excellent power filter. 

Best Power Filter Choice: AquaClear Power Filter

The AquaClear Power Filter is easily an excellent choice for power filters. There's a reason why it's one of the most popular, and highly-rated power filters sold today. 

For starters, it has mechanical, biological and chemical filtration. 

And that's not all: 

AquaClear Power Filter 3
  • Comes in 5 different sizes, from 5 gallon tanks all the way up to 110 gallon tanks
  • Very fairly priced, inexpensive 
  • Comes with a 2-year warranty, in case anything goes wrong 
  • Comes with a ton of different biological and filtration media, so you don't have to purchase anything extra 
  • Easy filter set-up 
  • Only recommend to clean twice monthly (instead of weekly for a lot of other commercial filters) 

The filter is very highly-rated, with 65% of over 2,500 consumers giving it a 5-star review. 

If you've read this far now, you should feel quite informed and a lot more confident about your decision. 

Hopefully this article helped you out. If so (or not), please leave a comment below and let TurtleHolic know! 

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Hi, I'm J and I'm the chelonian-obsessed creator of this website. Feel free to leave a comment below, as unlike a snapping turtle, I promise I won't bite!

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