skimmer for 120g long

[jedimaster1138]

I'm posting this here because it seems like the fine folks at Premium Aquatics (cough Jeremy cough) seem to have a really good grasp on skimmers. I've also been following the Vertex Omega thread for some time.

My tank is a 120g long, with a 40 ish sump. Mixed reef, but it's going to be heavy on the SPS going forward. 2-3 clams, LPS, fish that I feed pretty heavily (a happy fish is a well fed fish, I say)

I brought my Reef Octopus NWB-110 over from my 50g when I upgraded. It's fine...for now, still pulling out some stuff. That being said I know in a few months, as my stocking ramps up, I'm going to need more skimming horsepower. So I'm thinking about what to upgrade too. Note that I don't need to upgrade NOW, though NO3 is around 4 ppm currently, which is as high as I'd like to see it go.

Silence is key. Tank is in my living room. Wife won't like a noisy skimmer. Even my current NWB-110 is a little noisy - and gets worse so between cleanings, which is a bother.

Skimmers I've considered....

Super Reef Octopus 2000
Reef Octopus Open Volute line with the DC pump
Vertex Omega 150
Vertex Alpha 170 or 200

I have no problem spending more $ now to not regret it later. Speaking of - the Vertex Omega 150. Looks like a hot skimmer but I have a feeling it's going to be a tad under powered for my system a year from now when I have more fish and way more coral. I realize there are bigger models in the Omega line coming, but I have no clue when. Also, how they compare to the Alpha line, especially in regards to the silence of the pump (all Omega line will use the Sicce pump, right?) The Red Dragon is, I assume, the standard for silence and efficiency when it comes to skimmer pumps.

So I'm looking for a little guidance. Right now I'm seriously considering the Alpha 170. It seems like a beast that's worth the premium price tag. A specific question there though - does the 170 employ the RD 1500 as the 200 does? Or does it use a different Red Dragon pump? I seem to be seeing conflicting information on that)

I don't run ozone, or bio pellets, FWIW. My skimmer chamber baffle is currently at 8 1/4. Running it higher isn't a problem, and if I need a shallower depth, I can hack together a stand pretty easily.

Thanks in advance to one and all

[Jeremy B.]

Thanks for the inquiry. I really think that a good 6" body skimmer is the way to go on this size tank, and really up to about 140g - 150g display. Figure that you're stocking the tank - 120g, not the sump. So regardless of the sump being 20g or being 75g, it's not really changing stocking density at all, but rather just adding a little more water volume. I don't put too much weight into sump size when sizing a skimmer, unless the sump is extremely large 90g+ additional water volume, and even then I don't recommend drastic changes in skimmer sizing based on a really large sump on a system.

With all that being said, the best 6" body skimmers on the market are the Super Reef Octopus 2000 Int and the Vertex Omega 150 in my personal opinion. I have not yet ran the POV 6" for any length of time yet, so I can't give a lot of input on this one, but from the small amount of experience I have with the POV 8" it should run very well too.

The Alpha 170 is a good choice as well, but I still feel for your volume that the SRO 2000 and Omega 150 would outperform it. With the neck size on the Alpha I feel like that would be a better fit for a 140g - 180g display, and the Alpha 200 would fall in that 170g - 220g display size. There are only two 110v - 120v motorblocks used on all Royal-Exclusiv skimmers which are the Askoll 1500 and Askoll 2000 motorblock, then the differences are the size of the volutes, size of venturis, impeller head sizes, etc. That's how you can have an RD 600 or RD 1500 that is all the same size block. Kind of confusing, I know. There is no other water pump or skimmer pumps that is as quiet as what the Red Dragon's are though, the are the benchmark for noise level in our hobby.

Let me know your thoughts or questions, I'd be happy to help out.

[jedimaster1138]

Jeremy -

Thank you a lot for the detailed reply. This is the kind of information I've been looking for. Thanks for the pump motor block clarification.

I think at this point it's a 2 way race between the 2 Vertex skimmers...the Omega 150 and the Alpha 170. Obviously the Omega has the big advantage in terms of being half the price. But as usual, it's not that simple.

Can you give me some insight into how the neck size effects the efficiency of the skimmer? That seems to be something that's quoted often...neck size being a key point. The Omega has a 4 1/2" neck, IIRC, and a 6" body. I think the Alpha 170 is an 8+" body with a ... I guess 6" neck? Feel free to not spare the technical jargon, I have an engineer's degree around here somewhere

I think I just need a little more education on what sorts of negatives, assuming they can be classified as such, come with a skimmer that could be considered "too big" for a particular set up.

One more bit, while it's probably moot, I do have part of my sump dedicated as a coral frag grow out section. It's probably...12-15g total, filled 3/4 of the way. It probably doesn't matter, I see what you're driving at with the huge sumps/fuges bit, but just throwing that out there. I hope to, sooner than later, have if stuffed with SPS frags growing out to be sold to support this habit/hobby/addiction/obsession...

Oh, one more more thing (last one I promise) How sensitive are either of these (the SRO too) to water fluctuations and/or daily power offs for 30 minutes? When I feed right now I close a main return valve and shut off my return pump and my skimmer for 20 and 30 minutes, respectively. After 20 minutes the return turns back on, I open the valve, and by the time the water level stabilizes again, the skimmer is turning back on (it's all pro grammatically done with the apex). Now I'm not married to this feeding method. I suppose I could leave the return on, but I feel like then I'm not giving the fish a lot of time to grab the food. I could also shut the return off, but leave the skimmer on, but then the skimmer is going to be running in "normal water level" - currently 8 1/4" - and then probably 9 1/2" + because of drain empty out, back flow etc. I suppose I could also valve the drains, but meh. Anyway, just throwing that out there there as to how it would effect the skimmer. I don't want to be in a situation where the skimmer is going to have to "start over" building its head and take 12 hours to do so, every time I feed...

Thanks again

PS - special thanks for not immediately saying "get the alpha!" as it's the more expensive unit. Not dealing with a salesperson whose first move is to up sell you the more expensive item is a pleasure. That's the mark of a good and trustworthy person. So kudos to you.

Joe

[Jeremy B.]

Very generally speaking about protein skimmers the higher the ratio of air draw to neck size the better the skimmer works. With that said, there is not one magic point of emphasis you can really dial in on a skimmer to make it work, and work well at that, but for the most part a skimmer that has a high air draw to neck size ratio the better that skimmer usually performs. On top of that, the larger diameter the neck you have the more dissolved organics you need for the skimmer to react correctly and pull it out. I'm sure you've come across skimmers that you've had to run the water level really low at first and it ran with a really tall foam head on top of it, and as the skimmer cleaned up the water the higher you had to raise the operating water level inside the skimmer and it ran a shorter foam head. The same goes when you widen up the neck, you need more air and water to push the foam head, but you also want to match up that neck diameter to your volume of water, because at some point you can only have so much disolved organics for the skimmer to pull out. There does come a point where the neck diameter is just too big for a given amount of water volume.

Over the years there have been a few different skimmers that the manufacturer has really hit the nail on the head with the main things that go into skimmer performance:

- Body Design
- Pump Air Draw / Water Flow
- Neck Size
- Height

These skimmers in my opinion are the old EuroReef CS6-2 (RS135 later models), Older Reeflo Orca 200 and Orca 250, various older Beckett skimmers with the right pump, Vertex Alpha 200, Vertex Omega 150, Super Reef Octopus 2000 Internal, Super Reef Octopus 3000 Internal, Bubble King Super Marin 200 and Super Marin 250.

For reasons mentioned above these skimmer models are just extremely well balanced, and some of the best all-time performers I've seen. That doesn't mean that other models don't work well because they do, it just so happens that these specific ones are extremely well balanced and just rock on any appropriate size system you would put them on, period.

The Omega 150 has a 3.5" diameter neck, the SRO 2000 Int has a 3" neck, and the Alpha 170 has a 4.25" neck. It doesn't seem like much, but over a 6" vertical rise there is a 50% increase in volume between the Omega 150 and Alpha 170 neck sizes.

I hope all of this makes sense. Basically use this info as a really fine tune guide on skimmer selection for your system. There are many skimmers out there which will work just fine for you, but if you're OCD about skimmer selection (I am myself , then these are the things to look at.

[jedimaster1138]

Thanks for the detail Jeremy - the loon in me now has a spreadsheet listing various skimmers, their neck sizes, air draw, and the resulting ratio.

The Alpha 200 is uh, very good. It's too bad my skimmer chamber is only 16x16! (and that's it's nearly 1000$ ! )

Maybe I can make a decision soon...

PS - do you give an credence to the whole cone shape vs "inverted wine glass" shape or whatever they are calling it now?

[Jeremy B.]

Yeah, the Alpha 200 has a decent ratio, huh?

In my opinion a cone skimmer / inverted wine glass body has just the slightest edge in design performance over a standard cylinder body skimmer. With that said, I think you can put a good cylinder next to a good cone / wine glass skimmer of very similar size and pump configurations, and I don't think you could tell a difference. I have personally had an SRO 2000 Internal next to an XP 2000 Int cone and I think the SRO 2000 Int put out slightly more. I had an older Vertex IN-100 next to an ATB 840, and I think the IN-100 put out more.

From an engineering stand point I think cones are a better design, but I think the differences are so small that it might not warrant spending the extra money on it, and other factors come into play weighing more of an impact on how that specific skimmer performs than just that body design alone. In other words, no one has any way to quantify one being better than the other in our hobby.

Don't stress too much over it and just go with a skimmer that gets really good reviews, your inhabitants up top aren't going to care either way as long as it's working well.

[orly20]

[QUOTE=jedimaster1138;21381966]Thanks for the detail Jeremy - the loon in me now has a spreadsheet listing various skimmers, their neck sizes, air draw, and the resulting ratio.

The Alpha 200 is uh, very good. It's too bad my skimmer chamber is only 16x16! (and that's it's nearly 1000$ ! )

Maybe I can make a decision soon...



Hey what did you finally go with and how is it working for you?

[jedimaster1138]

I actually went in a somewhat different direction and got the Bubble King Double Cone 180 with the DC Red Dragon pump. It's a beast.

100% completely dead silent. I wasn't sure it was on at first. LOL

Easy to adjust. Forget all that messing with the volute malarkey. Increase or decrease the power to the pump. Adjustment made. I have mine at about halfway to full power.

Pulls out some VERY foul skimmate. I mean really foul. Even my dog leaves the kitchen when I put the cup in the sink to clean it


Great skimmer. Just not cheap. But worth it.