Protein Skimmers for your marine tank

Taking the mayhem out of marine fish keeping


Protein skimmers


A protien skimmer is, in my opinion, one of the most essential pieces of equipment you will need for your marine tank.


There are many marine tanks out there that are run successfully without a protein skimmer, indeed almost all of my smaller tanks (less than 180 litres) were run with no more than a couple of powerheads a piece. I would, however, still recommend using them, particularly if you are starting off in the hobby and/or trying to run a simple marine tank. It will help you keep nutrient levels down such as nitrate and phosphates which will, in turn make keeping your water parameters in check that bit easier.


Protein skimmers can either fit inside your sump (if you have one) or they can hang on the outside of your tank, either at the back or the side. They sometimes need modifying to fit as some tanks come made with wide, glass bracing bars which can mean the pipework on the skimmer is too short. This can usually be rectified with a bit of tweaking



Protein skimmers consist of an intake that draws water out of the tank, through a pump that releases the tank water into a chamber. Air is also drawn into the chamber through an air line and puts thousands of tiny bubbles into the water column. Due to the polarity of the proteins they are attracted to the air/water interface created by the bubbles.


As those bubbles rise to the top of the water column within the protein skimmer they become denser and the foam that is carrying the organics from the water starts to collect in the skimmer cup. This condenses into a liquid in the cup which can then be removed and disposed of thus reducing the amount of organics in your marine tank.


When you are considering which protein skimmer to buy and although this website is about marine fish keeping on a budget, it really is a case of you get what you pay for. Decent skimmers aren't cheap but you will always see the benefits from using one that is at the higher end of the market and ideally over rated for your sized system.


Some skimmers are designed to sit in a sump whilst others can hang off the side or back of your tank. Which ever skimmer you go for always try and go for one that is over rated for your system. For example I use a Deltec MCE600 on my lightly stocked 432 litre tank dispite these skimmers being rated for up to 700 litres (depending on stocking density). After flow and live rock your skimmer will be the thing pulling out the most fish waste in your marine aquarium and if you want the benefits of healthy live stock, vibrant corals and a tank that is relatively easy to maintain the it will pay to make sure you are skimming as much as you can.


Make sure you know how the skimmer will work, some of the older protein skimmers I used to use had the main body of the pump sitting inside the tank itself. This meant that day in and day out I had to look at a great, huge, black lump on the back wall of my tank that completely dominated my aquascape. Many of the higher end skimmers now that you can use without a sump sit on the edge of the tank and the only thing you see in the tank itself is a small intake pipe.


If you are running a marine tank without a sump or any other type of filtration you may want to consider a protein skimmer with some sort of additional chamber where you can put media such as filter floss or phosphate reducing media.


Helpful tips


Protein skimmers


If you are ot using a sump, when positioning your new marine tank make sure you leave enough room between the wall and the back of your tank for a 'Hang on Back' (HOB) protein skimmer


If you don't have a sump and are not intending to run any other sort of filtration choose a skimmer with a built in chamber that will allow you to use filter floss or filter meduims such as carbon or phosphate reducing media



Protein skimmers - in a nutshell

After live rock and flow which will filter your tank water your protein skimmer will be the most important piec of kit you will use to keep your organics down (nitrates and phosphates)

Don't worry if you are not using a sump, there are plenty of good quality, effective skimmers out there that will simply hang on teh back or side of your tank.

Protein skimmers work by mixing air bubbles in the water column within the skimmer so when chosing a skimmer look for the amount of air produced

Don't scrimp when buying your skimmer, there are plenty of decent second hand ones out there that are reasonably priced and it will be one of the most important pieces of kit you will ever buy.

If you can, get a skimmer that is over rated for your system, their efficiency may reduce as they get older anyway


There are many different opinions on when to start running your protein skimmer but I would suggest you run it from day one of your cycle. That way, not only are you giving it time to 'bed in' but you can start to get to grips with how it works, changing air flows and checking it won't leak!