Assuming the flamefest from last night has died down, I noticed an interesting post from Euroreef about their new pumps and impellers. This is in the ASM vs. Euroreef thread (
http://www.reefcentral.com/forums/showthread.php?s=&threadid=940689&perpage=25&pagenumber=2) and I noticed that Euroreef was trying to make the same point I was, namely that for skimmers that are well designed, the best objective criteria for skimmer efficiency and performance (efficiency defined as how well it skims - in this case efficiency does not have anything to do with electricity usage) is to look at how much air the skimmer is pulling (this assumes again that the skimmer is well designed and uses this air to produce lots of foam and manages the turbulence well so that the foam is properly exited from the skimmer). Let me restate my main point from my posting yesterday and ask for your data based feedback. I think when evaluating a good crop of skimmers and when you are looking to find the one that will be most efficient at removing nutrients, compare the airflow through the skimmer (either scfh or lpm) to determine which skimmer will do the best job. Does anyone know of a reason this would not be true? Keep in mind my assumption that this evaluation will only be done on top performing skimmers that already have a reputation for doing a good to excellent job of skimming.
The specific post from Euroreef announces that their new impellor (announced yesterday) can deliver 1080 lph using the Gen-X 4100 pump (the RC750 has three of these). I think that is about 38 scfh (is this right? Can someone check the math?) so it compares well with the beckett skimmer I was using as my benchmark.
With the new Euroreef numbers I have computed a new set of metrics to compare my skimmer pool. They are:
Skimmer Performance & Skimmer Pump
ER RC750 38 scfh (3 GEN-X 4100 pumps)
Deltec AP902 56 scfh (2 Eheim 1260 pumps)
H&S A200-2s1260 ?? scfh (2 Eheim 1260 pumps)
BK250 (ext) 53 scfh (1? Red Dragon pump)
AO Foaminator MAX 4000 45 scfh (1 Sequence/Reeflo UNO Tarpon)
Does anyone else know the appropriate airflow numbers for the H&S skimmer? Would it be essentially the same as the Deltec numbers? Yesterday I heard 30+ scfh for an Eheim 1260 NW pump. Deltec appears to rate theirs at 28 scfh (assuming I have the conversion right) but it’s possible they are conservative in their rating. If I don’t hear any other input I’ll use 30 scfh for the H&S but it doesn’t seem right to use different numbers for the Deltec and H&S unless someone knows they produce different results.
The NW air flow numbers I had been using were based on some ER Sedra airflow numbers. These are much larger and compare favorably with the beckett numbers (unless I decide to upgrade to a dual beckett skimmer). I am also starting to look much more closely at the H&S skimmer. If it really does 56 (or 60) scfh then maybe it is moving into first place in my evaluation. Based on this data it also appears that both the Deltec and H&S skimmers perform better than the BK although the BK is more expensive (I also backed down from the BK400 â€"œ it does 88 scfh â€"œ almost the same as the dual beckett skimmer - so it is clearly in a different league than these skimmers)
Any feedback on my methodology or results? I know there are other factors impacting skimmer performance such as geometry and turbulence but for skimmers that already have a proven reputation for being very good skimmers isn’t comparing airflow an effective way to measure the overall performance of the skimmer?
