Should There Be Some Sort Of Skimmer Sizing Standard?

[Forsaken77]

Thought I would ask everyone's opinion on this. It seems a lot of people over size their skimmer and some don't. But I'm guessing that some manufacturers take this into account, and some don't, when putting out their "recommended size."

Having a 200+ gallon gap in some skimmer ratings, between low-high bioload, seems a little lacking in available information. Such a wide margin could basically account for most tank sizes, leaving would-be customers more confused.

There really is no way to measure your bioload when purchasing a skimmer either. Some skimmers use the same pump, but suggest completely different gallon sized tanks.

Do you think it would be more helpful if there was a more "optimal" window of what size skimmer should be used? And should there be an industry wide standard for gauging skimmers so people are comparing apples to apples?

 

[User1]

Well, standards are just that, standards. However, not all skimmers are created equal not to mention the various number of different pumps people can use. So i don't see the value or need - my opinion of course. in 2000 I had a 100 gallon tank and purchased a skimmer. My requirement at the time was to find something built like a truck, consistent, didn't require daily fiddling, and future proof based on what I thought to be the biggest tank I would own - 300 gallons. Enter the year of 2018 I've since moved past that tank, downgraded to 29 gallon bio cubes and a 40 breeder with only recently (April) upgrading to a 210 gallon tank. Guess what, that skimmer handles this tank just as well has the 100 gallon. The design scaled and it has aged well.

 

[Forsaken77]

Well, standards are just that, standards. However, not all skimmers are created equal not to mention the various number of different pumps people can use. So i don't see the value or need - my opinion of course. in 2000 I had a 100 gallon tank and purchased a skimmer. My requirement at the time was to find something built like a truck, consistent, didn't require daily fiddling, and future proof based on what I thought to be the biggest tank I would own - 300 gallons. Enter the year of 2018 I've since moved past that tank, downgraded to 29 gallon bio cubes and a 40 breeder with only recently (April) upgrading to a 210 gallon tank. Guess what, that skimmer handles this tank just as well has the 100 gallon. The design scaled and it has aged well.

Over sizing some skimmers doesn't work though. Some, like a Deltec, are usually pretty accurate. In some cases, over sizing will not let the bubbles reach the top of the cup or the skimmer will idle because it's too big and be inefficient. So how would you know what will work and what won't if you're going out of the skimmers suggested range?

 

[jduong916]

Well, standards are just that, standards. However, not all skimmers are created equal not to mention the various number of different pumps people can use. So i don't see the value or need - my opinion of course. in 2000 I had a 100 gallon tank and purchased a skimmer. My requirement at the time was to find something built like a truck, consistent, didn't require daily fiddling, and future proof based on what I thought to be the biggest tank I would own - 300 gallons. Enter the year of 2018 I've since moved past that tank, downgraded to 29 gallon bio cubes and a 40 breeder with only recently (April) upgrading to a 210 gallon tank. Guess what, that skimmer handles this tank just as well has the 100 gallon. The design scaled and it has aged well.

What skimmer was it?

 

[Bpb]

It’s unfortunately something you cannot standardize. If you read some actual skimmer comparison experiments where a measurable amount of organic content is added to a controlled volume of water and duplicated for different skimmers of equal rating, the results vary widely. Some removing as little as 10% of that organic content others over 40% in a given time frame. No surprise the bubble king outperformed all in the most recent one I read.

Generally speaking, get something correctly rated if you run a light bioload, and go up a size of carbon dosing or running a heavy bioload. If your skimmer stalls for weeks on end and produces no skimmate, but overflows if you even think about adjusting it, it’s too big.

My Lifereef vs24 is “rated” for something like 250 gallons, but I am able to get a strong concentrated dry skimmate that fills the cup within a week on my 90 gallon. It literally stinks the entire house up if I remove the lid. So while on paper it is oversized, in practice it is perfect. But it is also well documented that Venturi skimmers aren’t the best most efficient performers in DOC removal. Their value lies in simplicity of use, low maintenance, and ease of pump replacement

 

[Daniel@R2R Verified Admin]

Good discussion! I do think that if there were some objective rating system by a third party, that would be ideal. It would keep buyers who aren't aware of variance between brands from confusing skimmer systems that are rated equally but truly are not.

 

[Gablami]

I also think it’s a great topic.

It’s true that if oversized, your skimmer may not produce skimmate consistently, and more gunk can get caught up in the neck. Also the tank size estimate is really a proxy for bioload. You could have a small tank with a ton of fish, or a very lightly stocked large tank and use the same skimmer effectively.

It’s hard to standardize sizes because a large component of “bioload” is owner dependent. The amount we feed as reefers varies dramatically, and thus for a similar sized tank, or number of fish, it’s hard to quantify “bioload”.

Still, there has to be a better way than what we have now.

 

[Antics]

I think the idea of "oversizing" a skimmer is more relevant for significant differences. Like a 400 gallon rating for a 40 breeder. If you have a 75 or 90g tank and get that same skimmer I'm sure it will be serviceable. Almost every aquarium in this hobby is overstocked or "high bioload" for the size. Embrace it.

 

[Forsaken77]

Maybe "bioload" or "tank size" shouldn't be the suggested variable then? How do you determine what is considered "lightly stocked" and "heavily stocked" anyway? Isn't that subjective to both the consumer and the manufacturer?

I don't really know what the answer could be. I have a tough time deciphering what skimmer size to get and I'm familiar with a bunch of brands (not even close to all). Because there are differences between manufacturers and even differences in the different models a given manufacturer offers. Then if your tank size falls into 2 or 3 different skimmer sizes, you really have a tough go at it.

It's basically almost equivalent to being blindfolded and throwing a dart at the board. Everyone wants what will produce best in their tank, but there's no way to know that without expensive trial and error. Maybe how much livestock are in your tank based on their waste, combined with tank size? I don't know.

I just feel that for the average person, "bioload" is not a helpful tool to figure out what you need.

I wish that there was a tds-type pen that could tell you what your nutrient level is, because tank maintenance plays a roll and everyone is different in that respect, so you can at least be closer to the optimal skimmer range.

 

[Antics]

Yeah, but skimmers are one of those products we all rate on the subjective eye test. Does it LOOK like its working? I think for 90+% of consumers in this industry you should assume you have a heavy bioload. Most people have too many fish, too large of fish, or are overfeeding. Any mix of that will be a heavy load as far as a skimmer is concerned. If you're not breaking any of those three rules, you probably would be fine without a skimmer at all and just performing routine water changes.

Skimmers are a tool, and instead of treating them (and equipment in general) like a character stat sheet that you're min-maxing, you should approach equipment within the triangle of a) what is my budget, b) what is this equipment supposed to accomplish, and c) where is the sweet spot between price, reliability, and performance. Trying to define or standardize equipment across brands isn't possible. In part because each company packs a little manure into the advertising/marketing of the "innovation" of their product and market research.

 

[User1]

What skimmer was it?

LifeReef.

 

[ca1ore]

It’s unfortunately something you cannot standardize. If you read some actual skimmer comparison experiments where a measurable amount of organic content is added to a controlled volume of water and duplicated for different skimmers of equal rating, the results vary widely. Some removing as little as 10% of that organic content others over 40% in a given time frame. No surprise the bubble king outperformed all in the most recent one I read.

But it is also well documented that Venturi skimmers aren’t the best most efficient performers in DOC removal.

I find both of those claims to be dubious - care to provide credible links. There haven't been many credible skimmer comparison studies. The one I recall most clearly was done by advanced aquarist back in 2010 and the conclusions were that skimmer design makes almost no difference and that DOC removal is about the same. Further, most of today's skimmers use a venturi.

 

[ca1ore]

I've posted a few times over the years on this topic over on that other forum. At one point, I asked a few skimmer manufacturers (when I still went to industry shows) about how they 'size' their skimmers and was left with an underwhelming feeling. Not saying they are necessarily 'made up', but there appeared to be very little scientific basis for the ratings. One actually said to me that that look at similar sized skimmer ratings and pick a number for theirs that 'seems right'. Chaps, we're on our own.

The reality, though, is that it's a very tricky thing to do. As folks have already noted, measuring the bio load in any system is next to impossible. Further, one person's 'high bio load' may well be another's 'medium'. I suppose it ought to be possible for skimmer manufacturers to rate their units in terms of grams-of- DOC-removed-per-day, or something like that, but since none of us know how many grams our systems produce, not sure it would actually be useful.

 

[Bpb]

I find both of those claims to be dubious - care to provide credible links. There haven't been many credible skimmer comparison studies. The one I recall most clearly was done by advanced aquarist back in 2010 and the conclusions were that skimmer design makes almost no difference and that DOC removal is about the same. Further, most of today's skimmers use a venturi.

I didn’t save the link from the experiment I read. If I come across it I’ll link it. By Venturi I mean the lifereef/MTC type design, rather than a needlewheel impeller

 

[ca1ore]

I see ......

 

[Blue Spot Octopus]

4" skimmer 75 gallon tank range.
6" up 135 gallon tank
8" up to 180 gallon tank

 

[Forsaken77]

4" skimmer 75 gallon tank range.
6" up 135 gallon tank
8" up to 180 gallon tank

Would you think an 8" skimmer would work properly on a 55 gallon tank?

 

[Blue Spot Octopus]

No unless you are feeding goldfish to a couple of moray ells, triggers and a dog face puffer.

 

[skim]

If you read some actual skimmer comparison experiments where a measurable amount of organic content is added to a controlled volume of water and duplicated for different skimmers of equal rating, the results vary widely. Some removing as little as 10% of that organic content others over 40% in a given time frame. No surprise the bubble king outperformed all in the most recent one I read.

I find both of those claims to be dubious - care to provide credible links. There haven't been many credible skimmer comparison studies. The one I recall most clearly was done by advanced aquarist back in 2010 and the conclusions were that skimmer design makes almost no difference and that DOC removal is about the same. Further, most of today's skimmers use a venturi.

Right article, and it was an interesting test and did prove a few things/or bring up some interesting points. The Skimmer that came out on top of this test I believe was the cheapest one, Precision Marine Air driven and Externally fed and the one that removed a certain amount the quickest was BK. I have believed for a long time the best skimmers will have 2 separate sections, one that creates the bubbles, being a pump or air stone/wooden block and a separate pump to deliver waste water in and out of the unit. With this set up you can control every aspect of the entire system. The two biggest factors in Skimming is Contact time and the least amount of turbulence. There are cert things that one can not change and one is the taller the skimmer the more efficient it will be and the longer a bubble stays suspended with low turbulence the more that will stick to the surface of that bubble and carry away. So next time you look at your skimmer and see that mix of bubbles that is swirling and bashing around at say 200 plus gal/hr what is actually able to stick to the surface of those tiny bubbles that are colliding into each other. Yes there are things that will but because on the lack of contact time and the massive turbulence it will be far less then a skimmer being 4 feet tall and all the turbulence at the bottom. I would say 90% of skimmers that are made and have been made/designed since the fall from the Beckett and Venturi ( not like todays but like Life Reef ) is do to public demand. Can't have a ugly mass 4 to 6 feet tall and 4 to 8 inchs round with this gunk spewing out into a large cup sitting in the Living room or Family room. Enough on this. The other point it should was Activated Carbon removes a fer larger amount 60 to 90 % but what is not clear is if it is the same DOC. The other thing I found interesting was, when the waste was tested that the largest component was Calcium and Calcium base micro organisms so here again the question, over skimming? Seen many posts, Calcium keeps dropping but Corals do not seem to be growing where is it going.
Anyhow just my 2 cents.

 

[Forsaken77]

No unless you are feeding goldfish to a couple of moray ells, triggers and a dog face puffer.

So then it's not "up to" 180 gallons . If I were to narrow down an 8" body (imo), I would say it would probably work optimally on a 150-210 gallon tank, assuming it has the right pump/air mix. But that's the thing, not every 8" body (or any other size) is equipped the same .

I have both a Deltec and an AquaMaxx with the same body size, yet the Deltec will work much better on a 180 than the AquaMaxx will. Therein lies the confusion.