Eheim Classic Canister Filter Unboxed, Tested, and Reviewed 2024

Eheim are one of the longest standing, most respected aquarium product manufactures in the hobby.

So I was excited to purchase the Eheim Classic External Canister filter and put it through its paces to see if it stands up to their high reputation.

After setting this filter up on my own tank, I ran it for several weeks to bring you what I like and don’t like, how it compares to other canister filters, and who this filter would be right for.

TLDR: Review Overview

I highly recommend this filter for anyone looking for a simple to use canister filter that’s reliable. 

The Eheim Classic doesn’t have a lot of bells and whistles, but it delivers straightforward operation that doesn’t require an engineering degree to set up and use, unlike some other filters.

It holds an enormous amount of biomedia and it performed well during testing.

My biggest gripe is that it doesn’t come with very much mechanical filter media. But, the  cylindrical canister shape makes it easy to add on your own aftermarket sponges and flosses.

Last update on 2024-04-19 / Commissions Earned / Images from Amazon Product Advertising API

How I Tested The Eheim Classic Canister Filter

I wanted to know what it’s like to really use this filter on a day-to-day basis. 

For years, I’ve read reviews and forum posts that touted this filter as the best, most reliable canister filter on the market. I’ve seen it described as a little workhorse that gets the job done without a bunch of hassle.

So, I set up this filter on my 40 gallon (151 liter) rainbow fish tank. I let the filter run for several weeks on my tank so I could get an idea of the real user experience.

I took a bunch of notes and pictures along the way so I could gather my thoughts and create a comprehensive review. 

In particular, I was looking at the following factors:

• Installation – was it difficult to get this filter installed?
• Priming – what’s it like to get this filter primed for the first time and after routine maintenance?
• Performance – does this filter maintain healthy water parameters in ​the tank? Does it help maintain the water clarity?
• Maintenance – how difficult was it to perform routine maintenance on this filter?
• Noise – how loud is this fiter? How many decibels does it emit?

What’s in the Box?

This Eheim is definitely the simplest canister filter that I’ve ever tried out. It does not have elaborate baskets or compartments to fit together.

Unboxing this filter was easy. Here’s what’s included:

• Canister
• Hoses 
• Spray bar
• Intake tube with strainer
• Carbon pad
• 2 plastic grates
• Reusable sponge
• Ceramic noodles
• Ceramic pellets
• Suction cups

Here’s a look at the criteria that I laid out earlier: 

Installation

Getting this filter installed was a breeze. 

This canister comes with a large bag of ceramic noodles and another bag that contains ceramic pellets. The ceramic pieces were very, very dusty after being jostled around in shipping. 

I got everything unpacked and made sure to rinse off all the filter media.

This Eheim is essentially just a big open canister that you layer the media in.

Online, I have seen some videos that show similar Eheim filters that have baskets for the different kinds of media, however, this model did not include any.

Once everything was rinsed off, I placed one of the grates in the bottom of the canister and put the ceramic noodles down on top of that. 

There is a blue reusable sponge that goes on top of the noodles and then you pile in the round ceramic pellets.

A carbon infused pad and a thin, fine sponge go on next and the whole thing is topped off with another plastic grate.

That’s it, no baskets or nifty dividers. This model is basically just an open cylinder that you place loose media into.

For long term use, I would highly recommend adding on more reusable sponges. The limited mechanical media will mean that more gunk and algae will cover the biomedia, possibly clogging it and restricting flow through. However, I set up this filter with only the media it came with.  

The hoses for this filter were really easy to cut to fit and they cooperated nicely when I was running them to the back of the tank.

For this install, I have the canister sitting behind my tank stand since the cabinet beneath the aquarium is not tall enough to house the filter. There are holes in the back of the stand meant for running wires and it was simple to feed the hoses through these so they could reach the tank.

Eheim gives you two quick connect valves for the hoses. To attach them, you cut short pieces of included hose (I’d recommend about 6 inches/15 centimeters long) and these attach to the intake and outflow ports on the canister. 

One end of the quick connect valve connects to the short piece of hose coming from the canister and the other end connects to the long hose that goes to the tank.

You can shut off the water and then unscrew the middle of the quick connect and it pops apart, it’s super simple. 

I really like these valves. They’re easy to take apart and hook back together.

I especially like the curved intake and outflow pieces that come with this filter. They’re easy to attach and fit nicely over the side of rimmed and rimless tanks. The large suction cups make a strong attachment to the inside of the tank.

My only gripe with the intake and outflow is that they’re a bright green color. I prefer for things like that to be black or clear so they’re less visible. The green detracts from the look of the tank a little bit, in my opinion. 

Overall, installation was quick and efficient. I got everything done in about 45 minutes.

A definite change from the 2 hour install times I’ve had to put in with fancier filters.

Priming

You prime this Eheim in a very different way than any of the other canisters that I’ve tried out. 

The intake hose connects to the top of the motorhead and the outflow comes from the bottom of the canister. 

You connect the intake hose but keep the outflow hose disconnected at the valve. You open the outflow valve and suck air through it. This will get water to start flowing into the canister. 

You connect the outflow hose and let the canister fill with water. Once you stop hearing gurgling, you plug in the filter and it should start right up.

Not the fanciest priming method I’ve ever seen, but it’s easy and reliable.

Priming after maintenance should be a breeze. The quick connect valve should maintain your siphon. When you reconnect the hoses and open the valves, water should automatically start filling the canister. 

I did have to unplug/replug the canister twice to get the motor to start drawing water after maintenance. But frankly, I’ve had to do that with just about every canister filter I’ve tried. Just be aware you might have to do this to get the siphon going. You only need to unplug for about 10 seconds before you reconnect to power.

Performance

Water clarity has been excellent while I’ve been using this filter. This tank has lots of live plants and is fairly heavily stocked. I haven’t had any trouble with detritus or cloudiness. 

My water parameters have been great. There is so much biomedia inside this Eheim, it could filter a tank with three times as many fish as I have in there. 

When I tested this filter, I found that it was capable of pumping out 105.11 gallons per hour (GPH). 

The manufacturer states you can use this filter for tanks up to 92 gallon (350 liter). But, I think the GPH is too low for tanks that big. 

I recommend this filter for 30-40 gallon (113-151 liter) tanks. This Eheim should be able to churn through enough water to process fish waste on tanks in that size range.

Maintenance

When I started this project, I thought that maintenance was going to be a big hassle with this filter, mostly because all the media is loose inside the canister with no baskets.

But I must say, I was pleasantly surprised by how easy it is to give this filter a good cleaning.

As I mentioned before, the quick connects on the hoses come apart easily once you shut the water off with the valves.

Then I just moved the whole canister to my kitchen sink. You can open the top hose valve, make sure to point the bottom one into the sink, and open the bottom valve and all the water in the canister will quickly drain out.

Then you just pop the motorhead off the top. Well, I say “just” but this thing creates a REALLY strong seal so I did have to fiddle with it a bit to get the top loose.

I took the grate, carbon pad and fine filter pad off the top. I sprayed the gunk out of the fine pad with the sink sprayer.

To get to the big blue sponge for cleaning, I just tipped the canister and poured the ceramic pellets into a bucket. 

Then I just grabbed out the sponge and rinsed it out in the sink. I rinsed the ceramic pellets with a little dechlorinated water to get off some bits of algae.

I put everything back together, placed the canister behind the stand and reconnected the hoses. 

All this took me about 25 minutes, easy, peasy, lemon-squeezy. 

This was all super simple and way less messy than servicing a lot of hang-on-the-back filters I’ve had over the years.

Noise 

I was really impressed with how quiet this Eheim is. When I measured the sound it emits with a  meter, I got a reading of 51.0 decibels. In a very quiet room, you can hear a light hum.

To be fair, this filter does have a much lower GPH than many of the other filters that I’ve sound tested. So, it’s a little more impressive that the Fluval 407 only gives off 51.9 decibels since it pumps out more than twice as much water. 

But, that doesn’t negate the fact that this Eheim runs very quietly. 

Overall Pros and Cons

Pros: 

• Very quiet
• Simple to set up
• Includes tons of biomedia
• Performs well, maintains good water clarity
• Easy maintenance
• Easy to cut aftermarket media to fit

Cons: 

• On the lower end as far as GPH
• Needs more mechanical media

Last update on 2024-04-19 / Commissions Earned / Images from Amazon Product Advertising API

How Does it Compare?

It was so much simpler to install this filter versus other canisters. It only took me about 45 minutes to get this filter up and running.

This filter might not have some of the bells and whistles that others do, but what you get in return is straightforward reliability that flat out gets the job done.

This Eheim filter was one of the quietest filters that I tested. Only the FX6 produced less sound. You’ll only hear a soft hum from this filter.

The tank’s water parameters and clarity were both excellent while using this filter. Things went really well. Like all the other canisters I tried, this filter had tons of room for biomedia that helped process fish waste from the tank.

I would prefer that this canister had more mechanical media. I think this is something that Fluval really does better than its competitors. The big reusable sponges you get with a Fluval catch tons of gunk and help keep the biomedia cleaner.

Maintenance was much simpler and less messy than some of the other canisters I’ve tried. Even though there are no media baskets, you don’t have to reach down into the dirty water to get the media out, unlike the Polar Aurora, Marineland and Aqueon filters. 

However, this canister has the lowest GPH rating in the group of filters I’ve tested. It’s rated for about 164 GPH. Compared to something like the Fluval 407, that’s rated at 383 GPH, 164 is pretty darn low.

That doesn’t make this a bad filter. But, in my opinion, if you’re wanting to filter a tank larger than 55 gallons (208 liters), this canister isn’t powerful enough and you should consider getting something else.

Who is the Eheim Classic Canister Filter Best For?

I think this filter is best for people with 30-40 gallon tanks. It will work well for fish only and planted tanks. 

It has worked very well in my rainbow fish tank. I may even leave this filter on the aquarium long term. This tank has a lot of fish in it and the Eheim has easily maintained the water parameters.

I would recommend putting a sponge pre-filter over the intake strainer if you plan on keeping shrimp in the tank.

I recommend adding on some fine matten filter media. Luckily, it will be an easy task to cut the sponge media since it just needs to be a simple circle, no corners or weirdly placed pipes to cut around.

I like how simple this is. This would be a great first foray into canister filters for beginners.

Last update on 2024-04-19 / Commissions Earned / Images from Amazon Product Advertising API