Filtration - Refugiums/Sumps 101


Reef Tank Filtration - Refugiums/Sumps

Filtration gets to be a touchy subject with most of us here. Other methods of filtration such as biopellet reactors, carbon reactors, zeovit reactors, nitrate reactors, tap water filtration, GFO reactors, and media reactors will be addressed in separate sections. This section however is primarily based around sumps/refugiums.
One, we don’t sell “canister filters” at all. We also don’t carry OR recommend the use of mechanical or biological media as any part of tank filtration. Just because we could make money off selling something, doesn't mean we'll carry it if we don't believe in it. These are items such as ceramic rings, plastic balls, mesh socks, or even slabs of porous material that look like a brick. The main reason behind this is because at Reef2Land we work in the aquarium industry. We do everything from simply feeding the tanks we have, to installation and maintenance, to dealing with the hundreds of customers a month who shop with us. Because of this we are consistently dealing with a lot of tanks, and a lot of feedback, on a daily basis (whether it be our tanks or customers' tanks).
In a brief way of explaining, we have seen most of these types of media accumulate a great deal of waste. Water then flows or "trickles" over this media as the accumulated waste is decomposing. Our perspective - these items almost resemble the equivalent of if we pumped all of our tank water through trash cans full of decomposing food. If we did this with our tank water it would flow into the trash can, over the decomposing waste, and then back into our tanks. We can’t understand why anyone would want their tank water flowing through something that contains waste for any period of time.
Sumps/Refugiums – When it comes to sumps/refugiums the rule is very simple, buy the biggest one you can fit. One reason for this is because it allows for a greater area to supply the most filtration. Another reason is because the extra room will also come in handy in the event you decide to add extra equipment such as reactors, a UV sterilizer, an ATO, a return pump, a protein skimmers, etc. Sumps/Refugiums come in many shapes and sizes for the many shapes and sizes of tanks. There are even hang on refugiums for smaller tanks that may not have built in plumbing.
Sumps/Refugiums are an amazing addition when properly utilized for all of their benefits. They can house the majority of your filtration, grow beneficial organisms, vastly improve water quality, maintain proper water chemistry and you can plumb additional equipment directly into your sump/refugium. This is the reason that we carry only top of the line sumps/refugiums here at Reef2Land. Because your entire tank relies on these vital pieces of amazing equipment in order to maintain peak water conditions, which is one of the biggest factors in maintaining a healthy aquarium. There is a tremendous difference between simply maintaining and ultimately succeeding in the reefkeeping hobby. 
On an ideal setup, such as what most of us that work here have, a sump/refugium would contain a skimmer, some sort of buffering compound (such as Fiji Gold or Miracle Mud) one or more forms of natural filtration (such as macroalgae, live rock and/or live sand), a UV sterilizer and a refugium light, which is usually left on around the clock. This setup allows for water to flow down from the display tank, over the natural filtration, where harmful nutrients such nitrates and phosphates are then "removed". Usually next in line the protein skimmer removes any dissolved organic compounds, that may be small enough to simply pass through your natural filtration. Fiji Gold and Miracle Mud are tank buffers that are used as an alternative substrate usually in the center refugium chamber.
One reason we strongly recommend people use a buffering compound is because they assist in replenishing the essential minerals and vital elements that are utilized by your tank inhabitants. The water is then returned to the tank ready for the next stage of supplying your tank members with the best possible environment.
For those unfamiliar with macroalgae, they are algae such as Chaeto, Caulerpa, Halimeda and Maiden's Hair. These are organisms that use undesirable nutrients, such as nitrates and phosphates, as a primary food source. Assuming they are provided with proper lighting, and a suitable growing area, they will do a very efficient job at harmful nutrient removal for your reek tank.
The only alga that we actually recommend out of this group is Chaeto, also known as Chaetomorpha. The reason being is we have studied all these algae for some time. Halimeda and Maiden's Hair do not appear nearly as capable of harmful nutrient removal as the other two. The main problem we run into with Caulerpa is it is an extremely aggressive growing alga. We haven't had the greatest luck with preventing it from spreading to the display tanks. Once it does, it is immensely difficult to remove. This is why the benefits of Chaetomorpha are far superior to the other 3 types of algae in our opinion.
I will briefly touch on the subject of refugium light, as it is a rather important factor. Some people prefer to put whatever refugium light they can find over their macroalgae as a means of helping it grow around the clock. However, there is a lighting method that I have a personal preference of which biologically makes more sense in my opinion. It is a somewhat more expensive method, but the advantages can far outweigh the costs. In my experience the light over the refugium is almost as important as the light over the display tank - which is why I run Kessil a160s or a80s over the macroalgae in my refugiums.
Macroalgae is an organism that, like any plant, requires light to grow. Supplying any algae, or plant, with better lighting will cause it to fundamentally perform more effectively, leading to a more beneficial result.
More adequate lighting also assists in preventing PH drops in the tank by consistently adding dissolved oxygen to the water.
Another type of filtration for sumps/refugiums we call “backup reefs”. "Backup Reefs" are when people basically build a smaller reef system under their display tank. They often contain nearly the identical natural filtration content of their display tank. Such as sand, live rock, and sometimes even a smaller clean-up crew; as long as they can't be harmed by pumps. 
Lastly a substantial benefit of sumps/refugiums is the considerable growth of Copepod colonies which can occur. These little crustaceans or "critters" are, for the most part, a valuable resource to almost every aquarium. The addition of live rock to any display tank or sump/refugium almost guarantees the introduction of copepods into your reef system. One primary contribution of copepods is their ability to act as a clean up crew, consuming excess food, detritus, and waste.  As their population increases they will become a valuable food source for your reef. They will be carried into the main display tank by means of the water flow, where they will feed many organisms of your tank such as corals, fish, invertebrates, and other tank inhabitants.
When it comes to sumps/refugiums we believe they are one of the top 3 essential part towards maintaining a thriving marine aquarium.  A part that should never be overlooked and should be one of the first purchases before starting a new reef tank.
If you still have any further questions about Filtration, feel free to contact us at