Surface skimmers in ponds and aquariums
Brief description and introduction to the article
Surface skimming is often overlooked in the aquarium hobby, many keepers have never been told about it, but it is often a great asset to the aquarium when trying to keep the water in a pristine condition. Often we can look at the surface of the water and see a greasy film appearing or froth at the sides of the tank without ever realising where it has come from or even how to deal with it.
The film and scum mainly derives from nutrients and proteins that are in the water column and rest at the water surface, many fish foods add to this problem due to the ingredients in their recipes and it can look very unsightly if not dealt with on a regular basis. One easy way of removing the film is to lay paper towelling on the water surface for a few seconds and then pull it out, this will remove most of the film but it doesn’t solve the problem and it certainly doesn’t keep control of the situation for long periods of time.
The easiest solution to nutrient and scum build up in the aquarium is to add a surface skimmer to the equipment which will remove excess nutrients and proteins from the water surface 24 hours a day, 7 days a week, leaving your water clear and the aquarium looking healthy. The fish will also appreciate this extra addition as the water quality will also improve. Not only will a surface skimmer improve the water quality but it will also increase the oxygen levels in the water as the surface is constantly on the move increasing the gaseous exchange taking place.
There are many types of surface skimmers available to purchase, some are designed for larger tanks, and some fit directly into the pipe-work of your existing canister filters while others may simply consist of a weir arrangement at the back of the tank where the water is drawn into a sump tank or a trickle filter underneath the aquarium. If you are not sure which models are suitable for your aquarium it is always best to ask before purchasing, there is no point paying out money for equipment that is not compatible with your tank. Protein skimmers and HOB (hang on back) filters will run independently with the skimmer already pre-set to take the nutrients from the water, you can purchase a surface skimmer in its own right if you have a smaller tank and are running internal filters. These are simply positioned into place with suction cups so that the skimmer level is equal to the water surface level, often these will have a toothed fringe around the inlet to prevent any debris from entering them and are powered independently with a separate motor. Other models, as mentioned above are connected to the pipe-work of canister filters, these are also mounted by suction cups next to the pipe-work and this is spliced so that they run inline as long as the filter is running.
The principle of surface skimming applies to ponds as well as aquariums, in most cases it is often required more for a pond due to organic breakdown of alien material that blows into the pond from outside. These models will be much larger and are often hidden into the build of the pond with the only access allowed to them for maintenance if they get clogged.
Suppliers of Surface Skimmers
Eheim are renowned for the quality of their products especially their canister filters so it is no surprise that they also manufacture a surface skimmer that can be positioned inline with the filter pipe-work. The advantage of this model is that it has a T-connector built in which allows two inlets, one for the skimmer and one for the filter inlet. This means that the water from the surface is continually skimmed plus the lower levels of water are turned over by the canister filter, if you wish to turn off the skimmer it can be bypassed so that the filter is never switched off. The price for this piece of equipment is approx. £30.00 ($45) so it will not break the bank and should provide many years of cleaning the water.
Fluval also supply their version of the surface skimmer and is supplied with fitting to attach to their own external filter pipe-work. It works in exactly the same way as the Eheim model but does not come with the T-connection so it is running constantly while the filter is also running. As it is a simpler model the prices do reflect this, most suppliers can sell the unit for £8-10 ($12-15) but it is also reliable even though it is very basic.
If it’s a pond surface skimmer that you are after Oase sell larger units that will fit directly onto a suitable pump, these can come in various sizes and even inlet shapes dependent on the size of the pond or if you are after the aesthetic look as well as it being functional. All of the units will come with a basket for removal of debris from the pond and vary in price from £8 ($6) for a basic style right up to £60 ($40) for a larger model.