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Some thoughts on marine filtration systems.

Article by : Moolis Moolman @ Pet Stop SA

The marine hobby has gone thru massive changes the last 20 years. This was not limited only to filtration but to every aspect from lighting, water parameters, additives, food and today’s topic filtration.

When I started up my first marine aquarium 25+ years ago, the local marine specialist shop owner (uncle Tom Bakker) excitedly told me about a brand new filtration system called “the drip filtration system” that apparently would replace the need of a under gravel aquarium filter for ever and would last years and years in this hobby. It was only 2 years before the new craze was “the Berlin system” and this was closely followed by the cyclone skimmer and each of these would replace the need for the previous filtration system. And so it went on and on year after year a “new system” arrive that would eliminate the “old systems” completely and this would be the one for the future.

Out of this I learnt that there always will be new inventions and adjusted old inventions used in a different way, to constantly update and change the landscape of our great hobby for the next year or 2.

So you should not expect this article to explain all the intricacy of each system or give you the ultimate version that would stay the best for ever. No, this article will give you some basic insight into the types and why they work or worked as well as they did when they were introduced.

Let’s start with my personal pet hate. The undergravel filter. This was the first big move taking aquarium keepers into the wonderful world of becoming good bacteria keepers. Although it was not clearly understood by everyone why it worked at that time, everyone knew it worked much better than the previous attempts at keeping fish alive in general. The concept is really basic in that, water is moved through the gravel at the bottom of the aquarium and thus gave bacteria a much bigger surface area to grow and multiply and this simplicity made it a huge success. But it also had a massive drawback! The same bacteria that helped to convert toxic ammonia and nitrite into nitrate also polluted the water very fast once the flow stopped, especially if the filter gravel was not cleaned regularly or it was old (over 2 years).

Another brilliant filter called the canister made its appearance in freshwater circles and quickly became a marine aquarium favourite. It was much easier to clean / maintain than the under-gravel filter but due to the design of the filter, the filter used so much oxygen that it limiting the bio-load of the aquarium and the price also made it quite expensive.

Then there was the “drip filter” that made keeping tropical aquarium fish a breeze and also had lots of success in the marine world. This was one of the first filters that was able to allow marine keepers to keep more fish in their aquariums, but still did not help with the scurge of marine aquariums up to that time, namely nitrates and phosphates.

Then the sump filter with all the variety of options it gave the aquarium keeper to customise his/her filter to suit their needs arrived. This is still one of the best ways to do filtration in any marine aquarium. Not only does it give you the freedom to customize your filtration but it also add to your water volume and boost your introduction of much needed aeration to a reef aquarium.

The same thing happened with our understanding of how toxic ammonia, nitrite, nitrate and phosphates affect the fish, invertebrates and corals. So with loads of studies made on the bacterial side they initially identified Nitrosomonas and Nitrobacter bacteria as the main active bacteria in our aquariums. Today there are a bacteria product called Special blend from Microbe-lift on the market that contain 19 active bacteria in one bottle, this bacteria is at present the backbone of all Pet Stop’s aquariums and our customers swear by it.

Understanding the essentials of bacterial cultures and types of bacteria available for reef aquariums led to the development of loads of different filter media over the years. This started out as just gravel and escalated to noodles, plastic balls and numerous other multilayer / multi surfaces Media available on the market. My personal opinion is that most of these normal bacterial media do not have a place in the current reef aquarium due to the restrictions placed by the media for bacteria growth or bacteria that can consume nitrates.

Live rock opened up a brand new world. Before live rock, the successful keeping of marine inverts and corals was really difficult and beyond the reach of normal marine aquarium keepers living inland. But live rock’s introduction into the aquarium made the keeping of non-photosynthetic corals and inverts much easier. It did not take a rocket scientist to realize the potential of live rock in the filter. Live rock introduced 4 essential elements into the reef aquarium filtration system, namely:

  • A natural source of micro and macro organisms coming out of the live rock constantly for the corals and inverts to feed from.
  • The natural removal of phosphates and nitrates by the organisms and bacteria multiplying in larger live rock pieces.
  • More space for bacteria to grow and multiply removing ammonia and nitrite as fast as it is been produced. AND
  • A very authentically looking decoration for a natural reef aquarium.

So your decorations is also your filter

With the massive jumps in knowledge regarding the working of bacteria in the biological cycle, calcium cycle and all the additives needed in a healthy REEF aquarium we know today that the balance between all elements and the limitation of other elements like phosphates and nitrates are all needed to ensure a vibrant reef aquarium.

So the use of filters that do not limit nitrates and phosphates are not ideal to use in a marine aquarium especially a reef aquarium. As does a filter that cannot accommodate the reefers need for adding reactors, skimmers, dosing systems and chambers currently available as well as the ones that are going to arrive in the near future.

As a closing thought – a good filter need to be:

  • Adaptable
  • Enable you to place all your different hardware and wiring together
  • Easy to maintain
  • Left with extra space for future use
  • Assist not only in filtration but also help with keeping water stable though accommodation reactors, skimmers dosing and surplus water.
  • Keep everything out of site so everyone can enjoy viewing the splendid reef and not the “guts” of it all.

The brilliant thing of today’s technology is that there are a solution for all your problems and you can decide if you want to go high tech or low tech after evaluating the pro’s and con’s on you and what you expect from your reef aquarium. So do not believe there are only one way to do it, there are many but the trick is in the combinations. You need to ensure the combination of systems and protocols in your reef aquarium are all working together!!!

Happy reefing

Always hooked on marines

Moolis – Pet Stop SA

012-751 2432


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