The Downsides of A Hang on Back Protein Skimmer - Taking a Look at the Cons

Welcome to Simple Reefs. This is a brand new website dedicated to taking the complexity out of Marine Aquarium Ownership. Our goal is to show you how you can own your very own slice of the ocean without spending a fortune. As well as giving you tons of easy to digest information on all things marine. Today we are going to be looking at the downsides of a hang on back protein skimmer.

If you have found yourself here, there is a good chance you are thinking about adding a hang on back protein skimmer to your aquarium. Perhaps you have a freshwater conversion or, maybe, you have an all in one aquarium? Either way, you are in the right place.

As I mentioned in our opening article about hang on back protein skimmers. I actually started my marine aquarium ownership journey using a hang on back protein skimmer (Bubble Magus E3) so I feel I am pretty well qualified to talk about them.

We have already talked about the benefits of hang on back protein skimmers but, let’s be real, there has to be some downsides? Well, there is, and some of them are quite significant. One, in particular, can be absolutely catastrophic so keep reading. First, let’s quickly recap some of our prior protein skimmer articles.

A Quick Recap

If you have missed any of our previous articles on protein skimmers, you might want to take a little while to catch up. We have gone into depth on them in a whole range of different ways.

• What is a protein skimmer and what do they do?
• How does a protein skimmer work?
• What are the benefits of a protein skimmer?
• What are the downsides of a protein skimmer?
• Do you need a protein skimmer in your marine aquarium?

This article follows on from our first article on hang on back protein skimmers where we explain what they are and how they work. You may want to check that out before we begin. Having already discussed the benefits of hang on back protein skimmers. We mentioned how they share many of the same pros as regular protein skimmers.

When it comes to the cons of hang on back protein skimmers, the same is true. After all, a hang on back protein skimmer does the same job as a regular protein skimmer. There are some issues that are very specific to the hang on back format, however, so let’s take a look at those.

The Downsides of a Hang On Back Protein Skimmer

The benefits of hang on back protein skimmers are all well and good, but, this is where things can get a little bit rough. While most of these are fairly minor issues. One of the downsides, here, is something that deserves special consideration when you consider adding a hang on back protein skimmer to your aquarium.

• Typical protein skimmer downsides like stripping nutrients, noise, etc
• Can easily introduce pollutants into your aquarium
• Limited options for larger aquariums and higher bioloads
• Less efficient
• Harder to dial in
• Can release micro bubbles into your aquarium
• Need space behind your aquarium
• Can be a pain to clean
• Can be on the ugly side
• Do you want to stare at a collection cup full of skimmate all day?
• Water spills are possible and, potentially, catastrophic

Some of these things are pretty obvious. Naturally, hang on back protein skimmers have all the pros and cons of regular protein skimmers. Meaning you have to consider the overcleaning of water, stripping of beneficial elements, the noise and expense etc. There are a fair few things that are very specific to the hang on back format, though, so let’s focus in on some of those.

Hang on Back Protein Skimmer Cons

The space thing can be a bit of a non-starter when it comes to certain aquariums. You need a good few inches behind your aquarium to fit a hang on back protein skimmer on your tank. If you tank is flush against the wall, it is a no go.

This can be easily rectified with some aquariums but others would require a lot of adapting to fit one in. Imagine trying to move a 300 litre aquarium without emptying it completely. It’s not an easy task. You can opt to install one on the side but this can be tough with narrow aquariums.

Hang on Back protein skimmers can be a bit on the tough side of life when it comes to cleaning. Taking them off and dismantling can be a pain. It is a lot easier to just grab one out of your sump than it is to move things around to take it off the back.

They can be on the ugly side of life, as well. It’s never fun to see equipment around your display if it is in a living room and some people are going to hate staring at that collection cup. I found myself cleaning the collection cup immaculately every single time I emptied it because it was pretty horrible to look at. It’s not such an issue on smaller protein skimmers but it is a noteworthy problem on large ones.

Some of the hang on back protein skimmer downsides are more specific to certain types of aquarium. Hang on back protein skimmers only tend to go up to a certain size. Meaning it can be hard to find one that will work well for larger aquariums with higher bioloads. They are, also, less efficient, in general, thanks to the way they work. Meaning a larger hang on back protein skimmer will be able to process less water than an in sump equivalent.

More Specific Issues

Some of the issues are very specific to the way hang on back protein skimmers work. For example, when returning the water into your aquarium, the protein skimmer can release micro bubbles which can irritate fish and coral. This is especially likely when the protein skimmer is new and “breaking in” meaning it doesn’t have a coating of slime inside the reaction chamber, yet.

In sump protein skimmers do this, too. But most sumps will have, what is known as, a bubble trap. Which is a narrow section of the sump designed to trap any bubbles before they enter the return section of your sump and end up in your display. These tiny bubbles can make your display aquarium look carbonated and fizzy. They tend to go away pretty quickly but it is worth keeping in mind. Some hang on back protein skimmers come with foam to trap the bubbles which helps minimise this hang on back protein skimmer downside.

Hang on back protein skimmers can be harder to dial in. They tend to need much more careful balance between air and water which requires a whole bunch of fine tuning and tiny adjustments. This can get a little frustrating, after awhile. You can end up in a cycle of tuning, waiting an hour, tuning a bit more, waiting another hour. They tend to suffer a lot more from your water level changing, as well, so keeping up with evaporation is important.

Another general protein skimmer downside, that is a much bigger problem with hang on back protein skimmers, is the introduction of pollutants into your aquarium’s water column. Hang on back protein skimmers are even more prone to this as they are right out in the open and pulling their air from the room they are in. Air fresheners, paint, deodorant, cleaning products, smoke, and other types of pollution are going to be sucked right into the tank. Meaning you have to be very careful about air quality in the room.

The Huge Problem With Hang on Back Protein Skimmers

This is the big one! I am not going to lie, this is a massive problem and a major con when it comes to hang on back protein skimmers. Water spillages are very possible and can be absolutely catastrophic. Even dialling your hang on back protein skimmer in can be a recipe for disaster. The problem stems from the fact that your hang on back protein skimmer is outside of your aquarium. Meaning the water inside of it can only go to one place if it overflows and that is down the back of your tank and onto the floor.

An example of how easily this can happen is simply through dialling your protein skimmer in. This involves adjusting the level of water in the reaction chamber relative to how much air is being introduced. If I want to do this with the protein skimmer in my sump, I simply take the collection cup off and adjust the water level until the bubbles creep to the top of the neck. It doesn’t matter if it overflows a little. The bubble trap in my sump will catch the bubbles and the overflow will be going straight into the water. No big deal!

With a hang on back protein skimmer, that overflow is going straight on the floor, bubbles and all. Meaning you really need to keep the collection cup on the skimmer and be ready to turn it off if anything goes wrong. It seems like a fairly simple issue, right? Get it dialled in with a bucket underneath and you will be fine. The thing is, however, hang on back protein skimmers can be very temperamental.

Overflow Chaos

There are certain things that can make your protein skimmer run extremely wet. Meaning it will, simply, overflow within seconds. You switch it on and the water level shoots up, even at the lowest water level possible. No bubbles are produced and water comes straight out of the collection cup or neck. This can happen for myriad reasons.

Adding treatments to your aquarium can be a nightmare as they can make your protein skimmer go haywire. Pollutants in the air can do the same if they are absorbed into the water. Even certain coral foods and amino acids can make this happen. I have experienced it first hand and it is not pretty.

If you add a treatment to your aquarium with a sump, it’s no big deal. Leave the collection cup off and allow your skimmer to overflow until the treatment no longer impacts the protein skimmer’s function. It’s all just going into the sump, anyways and will be returned to the aquarium. Don’t worry about it.

With a hang on back protein skimmer, this can be a disaster. It will overflow extremely quickly, all over the floor, and not stop until you turn it off. If you aren’t home when this happens, the protein skimmer will empty the aquarium right up to the level of its intake pipe.

The pump will then, probably, burn out. Leaving you with a soaking wet floor, damaged woodwork, potential damage to your aquarium’s cabinet, a broken protein skimmer pump and potential electrical issues depending on where the water went.

This is can even happen days later when you thought the treatment was gone from the water. The protein skimmer can appear, at first, to be completely fine before going haywire later and causing disaster. I am going to be adding an article reflecting my own personal experience with this problem in just a few days in our first “Mistake Monday” article. A feature where I will reflect on things that went wrong and mistakes I made on my marine aquarium ownership journey.

Exercise Caution with Hang on Back Protein Skimmers

Most of the downsides of hang on back protein skimmers are fairly innocuous. In fact, the vast majority of the issues are things that you would expect simply by looking at your average hang on back protein skimmers. Especially in larger aquariums where a larger protein skimmer is necessary. That last one can be a major problem, however.

Exercise caution with hang on back protein skimmers. Always have something to absorb water ready when you are dialling them in. Always make sure you are ready to turn them off at a moment’s notice. Never keep them even remotely close to electrics. Make sure all of your aquarium’s wiring has water loops and never run a hang on back protein skimmer while using treatments in your aquarium. Thanks for reading and spending your time at Simple Reefs.