Skimmer size debate!!??

[madweazl]

Nothing living therefore nothing to skim coming from the sump for one thing.

For another, the volume of water in the typical sump isn't enough to matter all that much in terms of a skimmer rating.

Last, how could skimmer ratings be based on sump size when they have no idea what size sump anyone will fit with a given display tank? What if you run sumpless??

So, just count all the displays, frag tanks, refugiums, etc....still size the skimmer according to manufacturer guidelines though.

Seems like the opposite:

By that logic, there isnt anything living in about 70% of my display either but it is the same body of water. My sump is roughly 18% (actual water level) of my displays capacity. What you've illustrated is the exact reason a skimmer shouldnt be rated on "tank size."

 

[Scott.h]

Where did you see this?

Seems like the opposite:

. It was slight sarcasm as if skimmers are 33% efficient run 3. That debate just doesn't sound logical to me. Every week when I clean my collection cup it smells like garbage and looks it too. The more I carbon dose the nastier it gets. So it's hard to agree with all of that. Although I have always thought that skimmers aren't as efficient as everyone thinks.

 

[mcarroll]

Ah-hah! That went straight over my head. (Doh! Making replies too late at night....or too early!)

Although I have always thought that skimmers aren't as efficient as everyone thinks.

You see that same rationale at work with lights and pumps too – I think it's related to the hype. Don't believe the hype.

Aside from the fact that skimmers do work at least to some significant degree, the #1 reason that skimmers are great is that they run essentially forever with no upkeep aside from basic cleaning.

If they still required air-stone replacements every few weeks/months I don't know if I'd even have one, for example.

 

[TaylorPilot]

. It was slight sarcasm as if skimmers are 33% efficient run 3. That debate just doesn't sound logical to me. Every week when I clean my collection cup it smells like garbage and looks it too. The more I carbon dose the nastier it gets. So it's hard to agree with all of that. Although I have always thought that skimmers aren't as efficient as everyone thinks.

How do you even measure the total DOC produced by the system. Sounds kind of suspect to me. Kind of taking a best guess and making a pronouncement like it is the gospel. It is interesting in regards to sizing, because with scrubbers, they base size on the amount of food added to the system. It makes sense. Nutrient in = nutrient out. Also, just basing it off of display size can be misleading. What if you have a 300 full of giant tangs and angels, or you could have that same system with a bunch of high $ wrasses/designer fish. Wouldn't you think the large fish system would require more nutrient removal. I guess that is why they base them off light or heavy loads. My point is that there is no hard and fast rule. Just guidelines.

Also, skimmers do more than just remove proteins. They remove CO2, oxygenate the water, buffer PH and can help in cooling the tank.

 

[reefwiser]

I would go back and read the papers I posted. Adding extra be carbon dosing just muddies the water. When you carbon dose the skimmer just pulls out that too so it makes it darker. A skimmer is one part of a filtration system for your tank. When you add a algae component be it refugium, Algae scrubber or algae reactor depending on your inclination. Then soup up your bacterial to handle the load on the tank you should have a more balanced tank to handle the total bio load on the Reef tank system.

 

[Starwar]

I just added a lifereef vs2-24 to my 90 gallon. I call it overkill but we'll see what happens. I do agree it's possible to have inconsistent skimming with going too big. But i like the idea of future proofing. Dont mind the lego blocks...it was the only thing i could find till i build a platform haha!

 

[madweazl]

How do you even measure the total DOC produced by the system. Sounds kind of suspect to me. Kind of taking a best guess and making a pronouncement like it is the gospel. It is interesting in regards to sizing, because with scrubbers, they base size on the amount of food added to the system. It makes sense. Nutrient in = nutrient out. Also, just basing it off of display size can be misleading. What if you have a 300 full of giant tangs and angels, or you could have that same system with a bunch of high $ wrasses/designer fish. Wouldn't you think the large fish system would require more nutrient removal. I guess that is why they base them off light or heavy loads. My point is that there is no hard and fast rule. Just guidelines.

Also, skimmers do more than just remove proteins. They remove CO2, oxygenate the water, buffer PH and can help in cooling the tank.

How does a skimmer remove CO2 and buffer pH?

 

[mcarroll]

Dont mind the lego blocks...

What?! Your post should be about the lego blocks! Genius!

How does a skimmer remove CO2 and buffer pH?

One and the same action...the atmospheric level of CO2 is what anchors pH levels in the tank.

CO2 can accumulate in the system if there's poor mixing with surface water where gas exchange happens.

A skimmer maximizes this mixing, which equalizes the CO2 levels in the water with the CO2 levels in the room/space where the skimmer runs.

 

[hart24601]

Exactly. The issue with getting a huge vastly oversized skimmer isn't with nutrients or "too clean" but getting it to work at all. I have experienced this and there are several thread of it too, but if get a humongous skimmer (neck size) you need a lot of DOC to build the foam head. Generally what happens is no head is produced no matter the setting until you reach a certain doc level (might take a day, maybe a week +) then boom, pukes out the top. If you adjust it while overflowing it works fine if you don't mind doc rising until the skimmer hits the level it needs and skimmes properly.

Now with how some manufacturers over rate skimmers it seems like you're going crazy oversized, until you look at ones like vertex with "real" ratings. Oversize one of those and you wont be happy.

It's fun to look at say vertex skimmer stats (gph, air in l/hr) and recommend tank volumes vs other companies and see the difference. It can be extreme.


Here is a good example. Now sure there are slight differences, but nothing really major. This is not a recommendation of a brand, both nice skimmers, but to show it can be hard to tell what is "oversized".

Vertex 180i and the aquamaxx CO-3.

180i specs - 28W draw. 1300 l/hr air intake
CO3 specs - 27W draw. 1020 l/hr air intake

Similar body size. The vertex rating is for 90-180 gallon tanks. The CO3 is rated 270-450 gallon tanks! If you have a 100g tank the vertex is "right on" while the CO3 would be up to 4.5 oversized, but they have very similar specs. Put a 4.5x oversized vetex (180i on a 40g or smaller) and it just wont work well.

 

[madweazl]

What?! Your post should be about the lego blocks! Genius!



One and the same action...the atmospheric level of CO2 is what anchors pH levels in the tank.

CO2 can accumulate in the system if there's poor mixing with surface water where gas exchange happens.

A skimmer maximizes this mixing, which equalizes the CO2 levels in the water with the CO2 levels in the room/space where the skimmer runs.

So a more accurate statement would be with adequate gas exchange, a skimmer would do nothing in regard to CO2 and pH?

 

[mcarroll]

Right. Or maybe that having a skimmer means you don't have to worry about it. It's not the only way to aerate or even necessarily the best way.

 

[Damion]

I have a co2 problem, and have to use soda lime media on the air intake of my skimmer just to achieve 8.1 with 9.5dkh (south FL, house closed up, AC on 90% of the year)
On my bucket list is to run a line from outside straight into the skimmer air intake.

 

[reefwiser]

If you run an air line you need to run the air thru a carbon filter. As you can draw in weed spray into your skimmer. An I can tell you it's not a good thing.

 

[madweazl]

I have a co2 problem, and have to use soda lime media on the air intake of my skimmer just to achieve 8.1 with 9.5dkh (south FL, house closed up, AC on 90% of the year)
On my bucket list is to run a line from outside straight into the skimmer air intake.

I had the same issue; weather was too nasty to open a window for a couple months. Been decent at night the past couple weeks up here the pH has been staying in the 8.25-8.35 range. Pretty soon, it will be too cold I was going to run a line up into the attic and vent it somewhere up there to cut down on various pollutants.

In reality, I dont really think it is any different than opening a window though.

 

[Damion]

If you run an air line you need to run the air thru a carbon filter. As you can draw in weed spray into your skimmer. An I can tell you it's not a good thing.

Good point, I could just connect an inline carbon filter/bug catcher and a sediment trap.

 

[gcarroll]

Further Studies on Protein Skimmer Performance by Ken S. Feldman, Kelly M. Maers
Elemental Analysis of Skimmate: What Does a Protein Skimmer Actually Remove from Aquarium Water? by Ken S. Feldman

Ed, although I agree with the methods used for doing the data collection in these studies, I have to question if any of the skimmers tested were optimally tuned during the test. In most cases, you can’t just drop a skimmer in and not expect to be fine tuning it for the next month or so.

The other thing I ask is if removing DOC’s from the tank is the only benefit that we should be looking for when choosing a skimmer. I feel that a skimmer is also a benefit to the system by injecting fresh air to the water which helps raise PH and ORP. This is the reason I always look at the amount of air that a skimmer is pulling as a factor when choosing a skimmer.

Another thing I question is skimmer ratings. Most of them are simply numbers pulled from thin air by the companies to say that their skimmer will do more for the money than their competitors. These ratings surely cannot be trusted.

Here are a few for comparison. I find some completely unexplainable when compared to others.

Royal Exclusiv Bubble King Deluxe 300 Internal Skimmer
Rating: 317g – 792g
Air: 2,500 l/h
Total Height: 24,1/2"
Body Diameter: 12"

Bubble King® Supermarin 300 internal
Rating: 396g – 1056g
Air: 2,500 l/h
Total Height: 23.62ʺ
Body Diameter: 12"

ATI PowerCone 250 I-Series Protein Skimmer w/ Pump
Rating: 250g-500g+
Air: 3000+ l/h
Total Height: 21.6”
Body Diameter: 10”

Vertex VX-300 Alpha Cone Protein Skimmer
Rating: up to 600g
Air: 3600 l/h
Total Height: 27”
Body Diameter: 12”

Orphek Helix 5000
Rating: 125g – 645g
Air: 2000 l/h
Total Height: 21.25
Body Diameter: 8”

AquaMaxx Cone 6 In-Sump Protein Skimmer
Rating: up to 750g
Air: 2520 l/h
Total Height: 23.3
Body Diameter: 12”

Deltec SC 3070
Rating: 1056g – 1268g
Air: 3000 l/h
Total Height: 27.5
Body Diameter: 12

 

[reefwiser]

Greg air intake is a good measure of skimmer thru put. One thing I do. It like about the current crop of skimmers is that they rely on a single pump to do all the work. If the Venturi input get blocked just a little it effects the air mix. One of the best skimmers I ever saw was the Klaes skimmer.
http://www.advancedaquarist.com/2002/5/review
It created a massive amount of foam and air as the Venturi was separate from the water input to the skimmer.