Jeremy Gay explains what features you should look for when purchasing a protein skimmer and highlights some of the most popular models on the market.
Pump
This supplies the skimmer with tank water and will also double up as the air supply on some models by way of a venturi. Pump strength is calculated so that the skimmer gets enough water flow through in relation to tank volume.
Not enough and it may not cleanse the water quickly enough. Too much and the proteins won’t get time to stick to the tiny air bubbles and rise up the skimmer body to the collection cup.
If the pump uses a venturi feedto draw in the air, some will be sold with a special impeller with small blades to mash the air and mix it thoroughly with the water.
Fittings
As good as any protein skimmer may be, it must be flexible enough to fit your tank. Choose one versatile as regards fitting and one that will fit several types if you have to move tanks. Check that stress bars and tank rims will be sufficiently cleared and you have room behind and above the tank for the skimmer body.
Flow adjustment
A protein skimmer often needs fine tuning for best performance. By controlling the flow of water through the unit, and sometimes the air as well, a perfect balance between air and water can be achieved so that the foam and skimmate will rise to the correct level to be collected.
Collection cup
This collects the skimmate, made by mixing the air and water. Skimmate should be dark brown, thick and smelly, so most collection cups are clear to enable you to see when they get dirty and need attention.
Empty and clean the cup regularly to get maximum performance from your skimmer. The larger the tank, or larger the load, the larger the skimmer you will need — and larger the collection cup.
Air inlet
Paramount to any protein skimmer, the inlet allows air to be mixed with the water, so starting the skimming process. Air intake is adjustable on some skimmers, allowing for some fine adjustment.
Reaction chamber
A good skimmer will create maximum contact time between bubbles and water, so all the proteins can stick to the bubbles before being collected.
Bubbles naturally rise, so skimmer designers use the water flow and design of the body to drive the bubbles down, making them stay in the water as long as possible before floating to the collection cup. The smaller the bubbles the better — and that also aids contact time as they rise more slowly.
Popular models
V2 skim
The model of choice for many marine keepers, the V2 skim offers versatility with affordability and function. Great for freshwater/marine conversions, this skimmer can be fitted to virtually any off-the-shelf or custom aquarium and, as a result, the range is very popular.
The smallest model, the V2 skim 400 is suitable for tanks of up to 400 litres, while the largest, the V2 skim 1500, will do tanks up to 1500 litres. Each model comes with a pump to provide the optimum flow rate, is ozone compatible and carries a one-year guarantee. Prices range from £88.07 to £195.73.
Deltec MCE 600
Few skimmer manufacturers are held in as high esteem as Deltec. The MCE 600 was the original, premium hang-on box-shaped skimmer, delivering a lot of performance even on large tanks.
This model has stood the test of time and is hailed by hobbyists and professionals alike as a great piece of kit.
The MCE 300 is a newer addition, though we still prefer the MCE 600. For serious applications go for a Deltec sump model. The MCE 600 sells for £312.95 (20% off for a short period) while the MCE 300 costs £179.95.
Tunze
Comline DOC skimmers won’t win awards for looks but are another well-made, German range of skimmers worthy of mention. Ranging from the petite nano DOC skimmer, choose either the modular Comline DOC, Classic DOC or Master DOC and get years of trouble-free service from a brand synonymous with quality and longevity.
The new DOC 9410 is part of the energy-saving Eco-energetic range and delivers 600 lph of air with a water flow of 900 lph — and for 16w. Prices start at £256.70 for the 9410.
Aqua Medic Turboflotor
The Turboflotor range is one of the most famous names in skimming and has proved effective in many sizes and situations for many years.
Be it internal, hang-on or sump mount, the Turboflotor really delivers.
The model pictured is one of the Blue range from Aqua Medic, and is now our preferred model to the rather dated Turboflotor Multi SL.
The Blue skimmers can be fitted either as hang on skimmers to the aquarium, or in a sump, and are made to perfectly suit the interesting looking Blue Reef Acrylic sump system. Prices start at £134.99.
The item was first published in the May 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.