[fencer]

General Skimmer Comments

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What influences skimmer efficiency ( 1-10 with 10 the most)?

Does cast acrylic make a better skimmer----------------3
Cast is usually used in situations that require strength like pressure application. Cast has strength in all directions whereas extruded is subject to cracking along the long axis. Cast is one reason why the cost is higher in upper end skimmers. Usually cast skimmers are finished better. Use of ozone may cause weakness in extruded plastic.
Overall skimmer geometry ---- 5.
There has been a rash of cone type skimmers. I have yet to see any manufacturer show numbers relating to efficiency. At most I would think you stand to gain less that 10% over non cone skimmers
Diffusion plate in chamber ----- 9
Allows for better intermixing of air and water. Although I did like the
Vortex action the coralife generated. Air draw is important, but too much can cause large bubbles with excessive cavitation. So trying to put a larger pump on a skimmer will not work
Height of skimmer----------------- 6
This used to be critical but newer designs have eroded any gains tall skimmers had ( skimz vs vertex). Still a longer pipe = greater retention times
Impeller design---------------------- 9
Design is critical for the air water intermix. Although the skimz and vertex impeller are almost identical the skimz wins out because it uses a low wattage pump and improved pump/skimmer design. If you look at a Coralife impeller it is it very inefficient. Beckett designed skimmers work very well but it requires a lot of energy to drive the beckett properly.
Pump Design------------------------ 7
Pump design is required to match the skimmer. The intermix chamber design is critical in small bubble generation. Wattage is not so important, as the Skimz is one of the better performers with small wattage pumps. I think if the pump is placed closer to the diffusion chamber you actually get better performance with less horsepower.

So what do I choose?

Determine what you can afford and then add 10% to what you are willing to pay.
Cut the manufacturers recommended usage rating by 50%
Buy used if possible
Ask Canreef members opinions
Try to buy newer technology

Final Thoughts

There have been a few articles claiming then the best skimmers are only able to extract out 30% of the total organic content in the water. One article also states that a using a wood diffuser is just as efficient as the newer skimmers. All skimmers will reach the same point. Just some of them will take a longer time. If you decide buy a high end skimmer you have a good skimmer and the resale value is good. So is paying a lot of $$$ for top of the line skimmer worth a modest gain in efficiency? I can’t say anything about BK skimmers since I have never used one. I will leave you with one analogy. I am Porsche and Alfa owner and I am never going to tell anybody they are a bunch @!^$$&& Really I do own these cars....and there great cars