Keeping a Successful Refugium


Remember those fresh water aquariums a lot of us started out with? And how many of use used live plants to help oxygenate the water and prevent nutrient levels getting out of control. Well its the same for a marine aquarium but its normally done in your sump tank rather than your display.



A refugium (A section of a sump tank designed to keep algae) is one of my favourite sections of my filtration. Now before I begin many people have a successful marine aquarium without a refugium. Like most things within this hobby, there is more than one option and they all have their pros and cons. Within this post I will simply refer to the use of algae in a refugium and the benefits of having one.


What is a Refugium?


That photo above is of a basic refugium (not mine, a simple google image) just to give you an idea of what one is. The basic refugium consists of algae, live rock and substrate (also know as mud) in a separate section to the display tank. Many people link up a smaller side tank or the most common place for a refugium is probably the sump. Mine is in my sump and works great.

For those who don’t know what a sump is, its a extra tank attached to your main display tank which is normally located under the tank within the cabinet. This is where all the equipment and filtration can be found out of sight leaving the display tank clear and clutter free. I didn’t always have a sump, but it is by far easier and makes the overall tank look much better and natural.


Anyway…back to a refugium. There are two main functions of a refugium in my opinion.


The first and by far most important reason is the exportation of nutrients such as nitrates and phosphates. As the algae grows, it uses up nutrients from your tank and you simply remove portions of the algae as it grows. Every handful of algae you remove is a handful of nutrients from your tank. The second reason is to allow a natural habitat for pods to grown in. It is a safe haven for them to breed and reproduce. Once the pod population grows they get sucked up by the return pump and into the display tank. Where they become a natural food source for your tank inhabitants.



Refugium set up


# Substrate



Many people don’t use a substrate within their refugium as it can gather detritus and be difficult to clean. I personally use miracle mud as its a great for beneficial bacteria and allows the pods a place to live. It isn’t need in a successful refugium, but I personally use it as I have heard good reviews for miracle mud. It is the same for live rock, many people have it in their refugium but it is not essential.

I use Ecosystems Miracle Mud and have had good results with this product. If you wish to use it to – Click Here


# Algae



There are many different options for your chosen algae. but the easiest, fastest in growth and most used is the cheato macroalgae. You want a simple, fast growing algae that is going use up nutrients at a rapid rate. Other more complex algae’s still do well in a refugium but they can cause tank crashes when they bread, or so I have heard. I would personally highly rate the use of cheato in a sump as it grows at an incredible rate…if you use the right lighting.


# Lighting



Often this part of the refugium isn’t given much though but this is a critical aspect of any refugium. If you want your corals to grow at a fast rate you supply them with the best lighting possible, correct? or it you want garden plants to grow you make sure they have enough sunlight, correct? its the same for cheato growth.

A good quality light to maximise the growth of algae making a refugium go from good to great in terms of nutrient exportation as cheato wont grow under a weak light.  Since I upgraded my lighting I have seen an increase in growth and my nitrate and phosphate levels are perfect. My refugium is so beneficial and reliable that I rarely test for these two anymore, unless I encounter problems.  But don’t worry, you wont be paying out for a highly expensive light like your display tank.


I simply use a 150w LED plant grow light (hence why my sump pictures are in pink/red light) and it works great. but remember, water and electricity don’t mix, so be care when installing into your tank.  I hang mine up in my sump cabinet but have heard of people resting it on egg creates or having it placed on a wall behind the cabinet. what ever is safest and best for your set up is what I recommend.

Take a look at the light I and many use – LED 150w Lighting


# Mangroves



Totally not necessary but I love them so had to mention it. These are slow growing trees that have a little impact on removing nutrients in the early stages but they make a great addition to a refugium and look cool. I would love them to grow up the back of my tank and give the who set up a natural feel, but its not for everyone. Its simply a nice addition to a reef tank and if wanted these can be placed into the main display tank.

If you are like me and love mangroves, check out these – mangrove seedlings


So there we have it, a basic walk through to a refugium, one of the filtration aspects of my tank that I would not go without. Its natural, low maintenance and highly effective when you use the right lighting.


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