Seeing as how I just ordered a new skimmer for my 180 gallon set-up, I thought I would explain how I pick out skimmers.
Here are the three simple rules of thumb that I used to pick out a needle wheel based skimmer. These are not hard fast rules, just my own personal guidelines that I have decided to use for myself based on what I have read. Nothing really too scientific about this, just my first hand experiences combined with what I have read. You have to also keep in mind; some manufacture stated capacities are based on very specific test conditions which are not always reproducible in the average set-up resulting in a stated rating that may not always be usable or 100% applicable to real life uses. That is why I like to pick out skimmers based on the below three simple guidelines:
1. Look at the airflow ratings (Liters per hour).
The reason this is important is to try to gauge if the pump will be capable to produce a lot of fine bubbles. The higher the air rating, the better the potential performance. Although a lot of skimmers will be set to use about 10% to 25% of the maximum air intake settings on the skimmer (in liters per hour), this will still give you a somewhat usable guideline even though manufactures will state the maximum un restricted air flow the pump is capable of. Higher l/hr ratings can produce larger amounts of bubbles as well as smaller sized bubbles which are two key factors for a skimmer to work efficiently. For my set-ups, I have had great success by picking a skimmer with a L/hr that is between 5 to 10 times the total water volume of my set-ups (display tank + sump water volume)
2. Look at the water flow rating (in gallons per hour).
This is the amount of water the skimmer will move. I look at this for two reasons. The first is to make sure the skimmer will be able create strong and turbulent flow to utilize the bubbles produced and push the crud up into the skimmer cup. The second is to make sure the skimmer will be able to skim anywhere from 4 to 6 times the total water volume in the set-up. However, as the air pulled into the skimmer will offset some of the water, you must subtract at least 25% of the flow rating to get a more realistic number from the manufacture’s stated flow rate. This should give you the minimum water flow you will get out of that skimmer (worse case situation) based on average air/water mixtures. For example, if the manufacture states the skimmer pump has a flow rate of 1000 gph, you should use a flow rate of 750 gph as that is closer to the actual amount of water it will move once air has been mixed into the water.
3. Get a good quality brand name skimmer pump
Look for a good quality skimmer with a good quality skimmer pump. This will also depend on you budget to purchase a skimmer. I personally pay more attention to the skimmer pump than the brand of skimmer. Pumps such as: Sicce, Red Dragon, Diablo, and Rock rank amount the better quality skimmer pumps, but there are a lot more out there. Take the time to research the brand and read a lot of customer reviews to get some firsthand feedback.
Also, many people have their own rule of thumb about using the manufacture’s recommendations on suggested water volume ratings. Some people will say to pick a skimmer that is rated for 2 times your total water volume while others will say 1.5 times. While these suggestions can be helpful, they would be best to be used only as a starting point. In addition, that approach my work well for lower to mid quality skimmers, however, it will mostly likely be very misleading for good quality and top of the line skimmers. I would still suggest to assess the capability of the skimmer pump (using the above three guidelines) as a more accurate approach to take. As long as it can help you base your decision on a little more detailed information and less on a manufacture’s suggestions.
I also try to assume that my aquarium will always have a very high bioload. That way, I will be less likely to be up-grading my skimmer in the future. The only reason why I had to up-grade my current skimmer is that I recently up-graded the tank size but did not initially up=grade the skimmer when I went to a larger tank and sump.
When I researched and selected the new skimmer I just ordered for my 180 gallon set-up (total of 250 gallon water volume), I knew I wanted a skimmer with 1000 to 1500 GPH and 1250 to 2500 L/hr. I also wanted a very good quality brand as I have the budget that will allow for that. This certainly helped me a lot to narrow down my choices and to select my next skimmer.
Rating Overview: 4.5 out of 5
Details of my ratings along with the manufacture’s specifications are contained below.
The below is taken directly from the manufacture’s website:
Skimz E-Series SK181 Protein Skimmer features the highly efficient Skimz ES2000 needlewheel pump, suitable for aquariums up to 750 litres. With the combination of the conical body and bubble plate, it is the most effective skimmer in its class by significantly reducing turbulence, bubble bursting and surface agitation.
The SK181 protein skimmer draws an air intake of 540 litres per hour. Low power consumption and superior performance makes the SK181 an excellent choice for reefers looking for a value-for-money, attractive yet powerful protein skimmer. No feed pump required. Skimz Sk181 draws water directly from sump.
Skimmer pump: 1 Skimz ES2000 needlewheel
The below is my own assessment after a few years of using a SKIMZ SK181 in sump skimmer
Price Point (4 out of 5):
While this skimmer is still reasonably priced, it is a little bit higher priced than other skimmers that perform just as well or at least close to the SK181 skimmer. You can typically find these skimmers brand new ranging anywhere between $375.00 and $475.00 throughout Canada and the USA.
Ease of Use and Set-up (4 out of 5)
This is not exactly “plug-n-play”, but it is not that hard to set-up and use. The instruction are clear and this skimmer should take you less than 5 minutes to assemble even if you have never assembled a skimmer before. When following the instructions to adjust this skimmer, you should have it dialed into your set-up after about 15 to 20 minutes of minor adjustments and abservation. I do like the fact that once you have your skimmer adjusted correctly, it will need almost no routine or even minor adjustments from that point on. The Skimz SK181 also started pulling some pretty nasty looking crub out of my water within about 2 to 4 hours of taking it out of the box and setting it up. There are a few pictures showing some of the steps involved in stepping up and maintaining this skimmer at the end of this review.
Overall Size (5 out of 5)
This is one of the qualities that I really like about the Skimz SKS181 skimmer. It has a very small foot print as well as being shorter than most other skimmers with similar capacities.
Noise Level (5 out of 5)
This is another good aspect of the Skimz SKS 181 skimmer. It makes very little noise when running and I would even say it would be among the quietest of the skimmers with this type of capacity.
Ease of on-going Maintenance (4 out of 5)
The one thing that I both like and dislike at the same time is how the Skimz SKS181 skimmer is designed to be taken apart. I do really like how easy it is for everything to come apart and be cleaned very well, but I do not like the amount of screws that are needed to remove in order to take it apart. I find the cup to be on the small size. I have it set for a thicker skimmate and I have to empty the cup every 5 to 7 days. However, these are very minor complaints when compared to the other aspect of this skimmer.
Effectiveness of Operation (5 out of 5)
The Skimz SK181 needle wheel pump design is very efficient, producing a very fine and thick layer of bubbles once the air intake is adjusted correctly. It comes with the Skimz ES2000 needlewheel pump in it. This skimmer is a 6 out of 5 in my books. Within hours of taking this skimmer out of the box, it started removing a lot of gunk from the water and it just kept getting better from there. Even after a few years of use, it is still removing an amazing amount of stuff from the water. The below picture is what I get in the cup after around 36 hours of use, even after running this skimmer for a few years.
Likeliness of Recommending this Skimmer to Others (4 out of 5)
This would be one of the true ways to really assess how well this skimmer preformed for anyone. In short, this is among the best skimmers that I have used and I typically recommend this skimmer to people that have enough room in their budget for one. This is also one of the few skimmers that I would at least somewhat agree with the manufactures recommend tank size for use. I have been using this skimmer on my moderate to heavy stocked 180 gallon aquarium with a 100 gallon sump and I am very happy with the performance and resulting water quality. Although I do feel that is seriously pushing the limits of this skimmer with my set-up, this is not the only form of filtration and nutrient export that I have on that set-up. I would have absolutely no concerns using this skimmer on heavily stocked set-ups up to 150 gallons in size (combined display tank and sump water volume) or lighter stocked tanks slightly larger.
This skimmer is also an excellent choice for a smaller or limited size sumps due to the small foot print taken up by the skimmer and its relatively shorter height.
Some Additional Information:
The skimmer pump can be maintained by removing the four screws (two on each side of the pump) from the front plate allowing you to remove the front plate and then the needle wheel assembly for cleaning. When you purchase a Skimz Skimmer the motor will come fully assembled.
The below shows all the parts of the skimmer as you would unpack them when you purchase this skimmer. I never did think to take any pictures before assembling my skimmer when I purchase it new. These are pictures taken after a detialed cleaning a did a little while ago.
Start by adding the bubble plate chamber to the pump
Slide the pump onto the skimmer base. It will lock into place.
Attach the skimmer body to the skimmer base
Attach the micro adjustable valve to the skimmer body
Attach the air intake assembly to the skimmer body and the skimmer pump
This only leaves the skimmer cup and skimmer cup lid and you are done.
When picking out a skimmer for your set-up, I would refer you to the below article which may help you select the correct skimmer for your aquarium