marineland emperor 400 review

at 8:25 am

For the last decade (or more) you could not have a discussion pertaining to the “Best HOB Filter” without two specific filters rising to the top, the Marineland Emperor 400 and the Aquaclear 110. Man, have times changed. While such a discussion must still consider the Emperor 400, it can no longer compete with the Aquaclear if the subject of noise levels is included. Since “noise” has a direct correlation to quality, the longevity of the newer Emperor filters must also be questioned.


Marineland is a shell of its former self, run to the ground by United Pet Group who has turned it into an offshoot of Tetra. The newer models of Emperor 400s reflect the change in philosophy resulting from United Pet Group leadership, quantity over quality. As a result, the Emperor 400 now sells based upon its former reputation, which is no longer as well deserved.


I have owned Marineland Bio-Wheel filters since the early 1990s. I have observed a decline in the quality of these filters over the years with a very sharp decline occurring around the 2008-2009 time frame. The filters look the same, they just do not run the same and they certainly do not sound the same. The two most recently purchased Marineland HOBs I own happen to be the loudest HOBs I own, with one of those being an Emperor 400.


I don’t want to come off as completely negative. The Emperor 400 remains a viable option. It’s not as if the decline in quality that is affecting this filter is not a universal problem. Basically, All manufacturing of All filters now occurs in China so the quality of All filters is suspect. The days of “make the best product and people will buy it” are gone, replaced by the “make the cheapest product and people will buy it”. Unfortunately, we, as consumers, support this change in philosophy so we deserve what we get. This is why the Emperor 400 remains a viable option. It is so much less expensive than it’s only (true) competitor, the AC 110. I purchased my Marineland 400 for $39, which is a great price on these filters. The competing Aquaclear is $89 (can be found on sale for $69). Still the Emperor is much less expensive. So if you can handle the noise, it is a better option because in reality, as a biological filter, it remains superior to the Aquaclear design.


Nor do I want to over emphasis the noise levels. If you want absolute silence, you do not need to be using HOB filters. When I first hooked up my Emperor 400, it rattled and hummed like U2 in 1998. 24 hours later, the rattle was gone, only the hum remains. It certainly is not as quite as its 2005 and prior version (versions with flow control knobs) but nor is it at jet engine levels. However, if you are in the same room with this filter, you will be aware that it is running.


EDIT: Several months after authoring this review, the filter has become somewhat quieter. It has reached the “bearable” stage. A hum remains and you will be aware of the filter if you are in the same room with it, but it is no longer nearly as obnoxious.


It is also an impressive filter. Open the box, pull it out, and the size of the filter will surprise you. The “water wells” are very deep for an HOB which allows for very large mechanical surface area of the cartridges. It also utilizes a much larger Biowheel than the Penguin line.


  • As a primary filter for those that simply do not want to go with a canister filter, it remains a viable option, potentially even preferred over the Aquaclear line (because it is a better bio-filter). Just be prepared to handle the noise.


  • As a secondary filter to be used in conjunction with a canister filter it remains a viable option, potentially even preferred over the Aquaclear line (because of costs). Just be prepared to handle the noise.


If “design” is the primary focus of the discussion of “Best HOB”, the Emperor 400 wins, hands down. If you include noise and noise as an indicator of quality, it does not.


  • Outstanding Biomedia Capacity – Best biofiltration capability of any HOB.


  • Large Biowheels– The inherent dynamics of HOB filters makes them undesirable as biological filters. Biowheels eliminate this concern. They are the only method of biofiltration where flow rate is more important than surface area.


  • Large Media Containers– Each Emperor 400 ships with two media containers. If using the Emperor 400 as primary filters, you should fill these containers with Eheim Ehfilav, Eheim Substrate Pro, or some similar (smaller sized) biomedia, to extend the bio-capacity. Combined, these two containers will easily hold more biomedia than can be included in an AquaClear filter, then you have the added biofiltration capacity of the biowheels.


  • Large Mechanical Surface Area– Mechanical filtration effectiveness is determined by surface volume (length x width) and flow rates. Combined, the two cartridges provide more mechanical surface area than other HOBs, including the AquaClear line. If using as a secondary filter optimized for mechanical filtration, you can include 4 cartridges (see “Suggested Modifications” below.)


  • Impressive Flow Rate– At 400gph, only the AquaClear 110 surpasses it. However, as it relates to biofiltration, the higher flow rate on the AquaClear 110 is pretty much wasted whereas it is not on the Emperor 400. As it relates to mechanical filtration, as mentioned, flow rate plays a significant role. Since the flow rate of the Emperor 400 is higher than most canisters, it can easily be optimized to become the primary mechanical filter on a tank (see “Suggested Modifications” below).


  • Marineland Customer Service– While manufacturing has moved overseas, Marineland Customer Service has not. They remain amongst the best.


  • Cost – A high end capacity filter at a reasonable cost.



  • Frigging Noise– Come on Marineland/Tetra/United Pet Group. Do something about it.


  • Quality – As far as materials used in construction of the casing, the Emperor 400 is an improvement over the Penguins. However, noise is an indication of quality construction, and the Emperor 400 fails here.


  • Tube length – In order to use the shipped tubing or mid -level strainer in a 55 gallon tank, it would have to be cut. Otherwise, you just connect the strainer to the first level of tubing, which means it is not at the optimal depth for mechanical filtration.

Emperor 400 Modifications:

I don’t use the manufacturer cartridges. Instead, I use Bio3 Emperor Filter Cartridges, only using the clamshell and blue sponge, setting the carbon pads aside, and using blue bonded padding cut to fit. If optimizing your Emperor 400 for mechanical filtration, you want to use 4 of these customize cartridges.

Use of these Bio3 cartridges (with blue-bonded padding and the blue sponge) greatly improves the mechanical filtration capability of this filter. To extend the biofiltration capacity, fill the included media container with Eheim Ehfilav (or other smaller sized biomedia). I prefer use of Eheim Ehfilav in this role because it retains biofiltration capabilities even when mechanical filtration is weak. Nor does it ever need to be replaced, just rinsed in tank water.

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