Sat May 21 9:45:16 UTC 2011One of the largest debates in the saltwater fish keeping world has to be whether it is beneficial to run a protein skimmer on the tank or if it is detrimental to the water parameters. There are many arguments for and against so hopefully this article will help you to decide which way your thinking will go on this subject.
I personally am a great fan of running these and always found my water was higher in quality than without one but it is up to personal preferences on which decision you make.
How does a protein skimmer work?
When you visit the coastline of your country and look at the waves coming in from the sea, they always have foam as they hit the beaches which often have a brown tinge to it, this is a natural way of skimming the water of impurities and a protein skimmer replicates this on a small scale. The term ?foam fractionating? is the term used to describe this process, it’s the foam that does all of the work. So on a small scale, the air bubbles inside the skimmer remove the waste by-products from the water, these are collected on the surface of the air bubbles due to a charge that is created as the bubbles are formed thus attracting the DOC’s (dissolved organic compounds). The charge is created as the surface tension required making the bubble in the surrounding water causes friction. The gunk is attracted to the bubbles as they are the same charge while the water molecules are an opposite charge. The air bubbles in a salt water solution take longer to dissolve than in fresh water which makes the skimmer far more efficient. As the bubbles burst at the top of the skimmer, the residue is left to collect in a cup which is emptied on a regular basis.
This process was first discovered in the water treatment plants when air bubbles were forced into the waste water and it resulted in cleaner water being produced.
Types of skimmers available
One of the earliest models of protein skimmers that were available for aquarium users to buy was the co current skimmer. These were very basic models that used wooden air stones to create the perfect size of air bubble. The air stone was located at the bottom of a long chamber with a collection cup at the top. As the bubbles burst the residue was collected in the cup and the purified water simply fell back into the tank. The main problems encountered with these types of skimmers was the amount of time the air bubbles were in the tube, the dwell time wasn’t enough for them to be efficient so their only option was to extend the chamber which made them very bulky items and not pleasing to the eye at the back of the tank.
The next upgrade to this type of skimmer was the counter-current skimmer. In order to solve the problem of having the chamber to large to be practical, the new style of skimmer fed the tank water in at the top of the chamber so that it would fall against the flow of the air bubbles produced at the bottom. This has the effect of doubling the dwell time of the air bubbles making the skimmer much more effective. This type of skimmer was used for many years and some of these are still available to purchase today.
Venturi skimmers became the most recent addition to the new range of skimmers available. No air stones are required with these models but a specially designed valve allows the tank water and air bubbles to enter the venturi chamber together and the waste product is still collected in a cup at the top of the chamber.
Advantages of using a protein skimmer
- If placed in the correct position in the aquarium i.e. before the filter it will remove most of the DOC’s and high level waste.
- They also help to oxygenate the water in the aquarium.
- Many of the newer models have compartments in them for the addition of extra filter media.
- Running the skimmer will aid the mechanical filtration as it will remove debris, as well as some of the parasite spores that may be present in the water.
Disadvantages of using a protein skimmer
- Skimmers cannot remove low level waste for the aquarium water, if placed incorrectly in the filtration system they are virtually useless.
- As well as removing the DOC’s from the water, they will also remove vital trace elements needed for coral growth.
- If medicating the tank, the skimmers must be turned off or they will remove the medication from the water.
- When the skimmer is first purchased it can be daunting trying to set the bubble level correctly, this can take up to 2 weeks before the plastic loses its static charge from the production process, once this charge has disappeared, setting the bubbles is much easier.
There are many types of skimmer available nowadays and most of the manufacturers are trying to make them as invisible as possible in the tank set up. HOB skimmer has been available for many years and even the chamber skimmers can now be attached to the back of the tank hiding the actual chamber. Many skimmers will actually sit in the sump of the tank; this is the most efficient way of using them especially if the water flows over a chamber of bio balls to create the foam prior to the water reaching the actual skimmer.
There are a couple of the larger companies who are trying to develop skimmers suitable for freshwater tanks and these should be available in the near future, the main problem with these is keeping the air bubbles long enough in solution to work effectively as the dwell time is reduced drastically when there is no salt present in the water. Most freshwater skimmers are used at present in Koi ponds but this should all change in the near future.
Document created on Sat May 21 9:45:16 UTC 2011