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This article is our detailed review of the Marineland Emperor 400 HOB Filter.

Below you’ll find a quick overview of all the filter’s best features as well as what we don’t like.

Then, we show you how to set up the filter, clean it, and address any problems that you might encounter while setting it up.

Lastly, we’ve included a few helpful videos and links to manufacturers manuals for even more detail.

Let’s begin.

Quick Overview Of The Marineland Emperor 400 HOB Filter

The Marineland Emperor 400 Pro Series Bio-Wheel Power Filter from Marineland is a powerhouse of biological filtration.

The filter includes two Bio-wheels that provide a living space for friendly bacteria, which filter out harmful chemicals in the water and help keep your fish happy and healthy.

The Emperor 400 also features a high flow rate, 3-stage filtration, quiet and efficient operation, adjustable intake, and a unique dual-pump design.

If you’re looking for an efficient and powerful filter with the best in biological filtration, the Emperor 400 may be the best HOB filter for you.

The Best Features Of The Marineland Emperor

  • The Bio-Wheels are an extremely efficient way to up the biological filtration capabilities of your aquarium.
  • There is also a second intake in the middle of the intake tube to ensure all of your tank water is getting pumped into the filtration system.
  • This filter features a unique two-pump design.

What We Like About The Emperor 400

  • Two Bio-wheels give you the best biological filtration possible.
  • 4 filter pad slots ensure all water passes through filtration media.
  • High flow rate and adjustable flow.
  • Extra-long, adjustable intake tube.
  • Durable, quiet, and efficient.

What We Don’t Like About The Emperor 400

  • Need to be careful NOT to clean the Bio-wheels with tap water.
  • Spray bars can get clogged with debris, preventing Bio-wheels from spinning.
  • May become noisy after a lot of use (this can usually be fixed).

What You Need To Know About The Emperor 400

The Emperor 400 is a HOB aquarium filter that is powerful, efficient, quiet and has unparalleled biological filtration with its two Bio-wheels. This filter also provides mechanical and chemical filtration through its 4 filter pad slots.

The Marineland is a very quiet and efficient filter and has a very high flow rate. It can handle 400 gph, and it’s rated for tanks up to 80 gallons.

This filter features a unique two-pump design.

The first pump pulls water through the intake tube and runs it through the filter, while the second pump pulls water into the spray bar system and sprays the top of the Bio-wheels, which makes them spin through the water.

What About Those Bio-Wheels?

Marineland Emperor 400 Pro Series Bio-wheel Power Filter - Up to 80 gallon, Rite Size

The Bio-wheels are the big selling point of the Emperor 400 and for a good reason. Bio-wheels are an extremely efficient way to up the biological filtration capabilities of your aquarium.

But there are some things you need to know about Bio-wheels before you jump into buying this filter.

Here’s how they work:

The Bio-wheels are made of porous material that provides a friendly habitat for beneficial bacteria to flourish.

Marineland Emperor 400 HOB Filter Bio Wheel

As the Bio-wheels spin, the bacteria come into contact with as much of your tank water as possible. This lets the bacteria break down harmful ammonia and nitrite in the water and convert them into the less-harmful nitrate.

This means healthier fish and a better-functioning aquarium.

When you clean your power filter, it’s crucial NOT to wash your Bio-wheels. Even just rinsing them with tap water will kill much of the bacteria living on them, and then you’ll be back to square one with your biological filtration.

We recommend just dropping them in the aquarium while you’re cleaning the rest of the filter.

Some owners of the Emperor 400 have reported that their Bio-wheels stop spinning after a while.

We have found that this is usually due to clogs in the spray bar system, so make sure you keep your spray bars free of debris, and you shouldn’t have any problems.

Filter Specifications

Dimensions

The Emperor 400 is on the larger side for a HOB Filter. The assembled dimensions are 17 x 11 x 8 Inches (L x W x H)Manual.

Marineland has a very detailed product manual for the Emperor 400 available online you can view it by clicking here.

If you purchase the product, a copy is included in the package.

The manual includes the basic things you would expect, like safety instructions, part identification, assembly instructions, and a troubleshooting guide.

Marineland Emperor 400 Parts

As mentioned above, if you refer to the product manual, you’ll find a list of all the parts that make up the Emperor 400.

However, here is a list of the main parts and equipment for this filter;

  • The Impeller
  • The Intake Tube
  • Mid Level Intake Strainer
  • Extension Tube
  • Bio Wheels
  • Spray Bar
  • Filter Cartridges (Rite-Size E)
  • Filter Cleaning Brush (Bonus)

Below we’ve put together a chart of all the replacement parts along with their identification number and a link so you can easily find a new part if you need one.

Replacement Parts

Description

ID #

Two-Way Hinged Cover Assembly PR11305
Flow Manifold Housing PR11389
Impeller PR2121
Flow Manifold Housing Cover PR2122
Intake Tube PR2111
Mid-Level Intake Strainer PR11297
Extension Tube PR2112
Strainer PR2110
BIO-Wheel PR2140
BIO-Wheel Bearings PR2141
Spray Bar PR2130
Spray Bar O-Rings PR2045
Refillable Media Container PR2150

How To Set Up The Marineland Emperor 400

1. Install Filter Cartridges & Bio Wheels

Start by rinsing the filter cartridges, then place the media cartridge in the media container and insert it into the filter box with the blue side facing the back.

Next, place the Bio Wheels into the Bio-Wheel bearings.

2. Assemble & Insert The Intake Tube

  • Start by attaching the strainer to the extension tube.
  • Then attach the extension tube to the mid-level strainer.
  • Next, attach the mid-level strainer to the bottom of the intake tube.
  • Lastly, insert the intake tube (short end) into the filter box and connect to the flow manifold housing.

3. Hang The Filter Box & Fill

Next, hang the filter box in your aquarium’s desired location, fill the filter box with water (priming). Place the cover on and plug it in.

After that, the filter will make a few sounds as it starts to work the air out of the system and begins to pull water from your aquarium into the filter box.

If the above sounds difficult, watch the following video;

Here is a link to a setup manual from Marineland.

Adjusting The Water Flow

To adjust the water flow, you can adjust the mid-level strainer.

While this won’t do much, it helps a little. This, in my opinion, is one downside to this filter as most other HOB filters have some way to adjust the water flow.

How To Fill The Slot Filter Cartridges

There are two steps to installing the media.

First, you’ll need to take the filter media cartridge (colored blue/white) and insert it into the filter container and clip it closed.

Once this is done, slide the filter container into the filter box with the blue side facing the filter’s back.

How To Clean The Marineland Emperor 400

Impeller Cleaning

To clean the impeller, you’ll need to remove the flow manifold housing (Refer to the manual) from the filter box.

Once you’ve done that, pull out the impeller, rinse it under some warm water and clean the inside of the manifold housing with a brush to ensure it is free from debris.

Then replace the impeller and manifold housing into the filter box.

Filter Maintenance

For the best performance, you should ensure you complete the following task;

  • Clean the impeller each month
  • Replace the filter cartridges every 2-4 weeks
  • Clean your spray bar and intake tube each month

When Should You Change The Filter Media And Bio Wheels

As mentioned above, you can change out the filter media every 2-4 weeks, depending on your stocking levels.

Regarding the Bio Wheels, you should never clean them or replace them. Some build-up and discoloration are normal. If you find that excessive build-up affects performance, you can rinse the Bio Wheels with aquarium water during a water change.

What Size Bio-Wheel Does The Size Bio-Wheel Does The Marineland Emperor 400 Use

The Marineland Emperor 400 Uses The PR2140 Bio-Wheel and is available here.

Troubleshooting The Marineland Emperor 400

Below we’ve listed a few of the most common problems people face after they’ve purchased this filter.

You’ll find the problem, the most common reason it might be happening as well as the recommended fix.

Impeller Or Mechanical Noise

Mechanical noise is usually a result of the impeller, so run through the following checks;

  • Check that the impeller is installed properly and free of debris.
  • Replace any worn or damaged impeller
  • Ensure that the water level is not below the recommended levels

Spray Bar Not Working

This is typically a result of mineral deposits building up on the spray bar and cover the holes.

To fix this, take out the spray bar, clean the outside, and ensure it is free from debris or mineral deposits.

Cleaning the inside with a brush will help clean the inside of the tube.

Gurgle Sound

Gurgling is usually a result of air getting into the system. The most common reason is a crack in the intake tube or not assembling them properly.

Check the intake tubes for cracks and replace them as required.

Bio-Wheel Not Turning

You should note that the Bio-Wheel will not spin constantly and irregular spinning and brief pauses are normal.

The most common reason the Bio Wheels stops turning is the axles have become dirty and need quick cleaning. Pop the Bio-Wheel out and clean the axle, then place the Bio-Wheel back in place.

Not Pulling Or Sucking Water

If your filter isn’t pumping, pulling, or sucking water, it could result from a few things. Run through the following items;

  • Check that your power is working.
  • Check that the impeller is installed properly and free of debris.
  • Ensure that the water level is not below the recommended levels
  • Clean the intake tube with a brush

Water Coming Out Of The Intake Tube

This is typically a result of improper assembly. To fix this, take apart the intake tube parts, reassemble and insert it firmly into the filter box.

Hands-On Marineland Emperor 400 HOB Filter

This filter is made of very high-quality materials and seems to be very durable. It’s made of a black plastic material that is both heavy and flexible and seems less brittle than the clear plastic that you’ll find in other filters.

In our time with this filter, we’ve found that it’s tough to break, doesn’t leak, and doesn’t show wear as quickly as other HOB filters out there.

Many other filters out there have intake tubes that are too short, but the intake on this Marineland Pro Series Bio-Wheel Power Filter is very long. That means you can put your intake at the bottom of your tank.

There is also a second intake in the middle of the intake tube, which helps prevent dead zones and ensures that all of your tank water is getting pumped into the filtration system.

The four filter pad slots are a bonus, and you can easily swap out the included foam pads with bags of activated carbon or other filtration media if you prefer.

Buy The Marineland Emperor 400 Power Filter

Crystal clear water and healthy fish are a hallmark of this Marineland Power Filter. The high flow rate, efficient filtration, and dual Bio-wheels combine to make this one of the best filters on the market.

If you’re looking for efficiency, high water flow, and the best in biological filtration available, then you should be looking at the Marineland Emperor 400 Pro Series Bio-Wheel Power Filter.