Who rates skimmers

[Parker]

I've enjoyed the back and forth banter, I've learned a lot.

I think its safe to say there is limitless ways of doing things and limitless reasons for doing them. Once you throw a human into the equation math and science can go right out the window. I know I've made some choices based on ascetics rather then what might be considered best practice.

[sphelps]

Originally Posted by mr.wilson

I know, most people would rather do their own dentistry than drill into a new protein skimmer

And for good reason, quite often skimmer bodies are very thin to cut down on costs and acrylic can become more brittle from extended use.

Originally Posted by mr.wilson

Never say never. Technology and methodology is always adapting and evolving. If a sudden increase or decrease of flow ever occurred I would spin it as "intermittent wet skimmate to remove strongly hydrophilic proteins"

Interesting but I see fish poop on the floor as simply fish poop on the floor. External skimmers can make a big mess which is why I see a pump as a clear advantage.

Originally Posted by mr.wilson

Such as...

Well this thread is about skimmers and another discussion regarding turnover flow is currently taking place in another thread, I didn't want to be too repetitive but...
http://canreef.com/vbulletin/showpos...4&postcount=15
Basically I think it's fairly obvious that more return flow means more filtration. A sump is essentially a filter, bigger filters with more flow, filter more water quicker. A typical skimmer is independent from return flow and will essentially work the same regardless of return flow (in limits). Eliminating or reducing the need for additional power heads or closed loops is also a big plus in my book and I believe it results in a simpler system. You can increase in tank flow all you want but if you're limited by return flow your filter is also limited, higher return flow will not only keep particles and matter suspended but it will also filter them out faster. Not everything rises perfectly to the top of a tank and gets filtered out through the overflow in real life. Surface skimming is always going to be limited by blocks we install to prevent creatures from escaping and high total tank flow keeps things mixed up. I've also seen surface skum build up problems with lower flow tanks.

Originally Posted by mr.wilson

You haven't gone into any details other than "everyone else is doing it", and from my experience they are not all doing it. In my travels I see 3-5x the volume of the tank to be the common practice for return pumps. Apart from theory, in practice I use 3-5x the volume with a total tank flow rate of about 20x the total volume.

Dr. Stephen Spotte said it best "The successful maintenance of a seawater aquarium is mostly witchcraft mixed with a little science. In this book I have attempted to describe the science, but with the realization that understanding the witchcraft might be more useful."

Unless you care to share some of your witchcraft, we are stuck with my science

Well your science isn't that scientific, it's really just an opinion based on your own experiences and some information from various sources, just like mine.
To me turnover means the flow turned through the sump. Pure closed loop, in tank flow doesn't really turnover anything. I prefer to practice around 10x turnover with additional in tank flow if required, many times this is not required as tank demands are based on coral species kept. I've gone into as much detail as you have on this subject, perhaps it's split between two threads but it is there. The problem is it doesn't really mean anything without evidence to back it up which is why I for one look at other peoples experiences as well rather than being blinded by my own.

Originally Posted by mr.wilson

I contribute regularly to RC threads, but I have never bothered to read more than one or two TOTM profiles. I don't find them to be completely honest or particularly reflective.

Well I for one do enjoy reading TOTM profiles, I think it's interesting to see what successful tanks use for equipment and I think a lot can be learned from other peoples experiences. Taking ideas from a group will almost always produce better results than taking ideas from one individual. I'm not sure why you would consider such a thing dishonest, perhaps the parameters aren't always that accurate but the equipment and healthy corals looks awfully real to me.

Originally Posted by mr.wilson

There is no cause and effect of what you are claiming. If sure most of the tanks were glass rather than acrylic and used metallic pumps rather than magnet coupled ones, but this doesn't offer empirical evidence of anything. If you look at the TOTM historically you will see an evolution of technology and methodology. To deny this is to deny progress, and that is what I see with your opinion.

Why on earth would I deny that, of course progress exists. There's obviously more involved in these tanks but the maintainers of such aquariums seem to know what they're doing, if you want to believe it's just all luck and witchcraft that's your call.

Originally Posted by mr.wilson

I'm more experienced than smart, but I'm getting there. I have the advantage of 30 years of mistakes to learn from. I'm done making most of them

Well I guess we're opposites which is probably why we get along so well , I consider myself smarter than I am experienced. I have an engineering degree and I believe I pick up things faster than most people. Where I lack personal experience I have to rely on other peoples experience to fill gaps when necessary.

Originally Posted by mr.wilson

I'm active on a few sites, so I decided to divert some of my time over to this forum. This forum seems more active than the other Canadian site I belong to that I won't mention

I don't expect anyone to do a 180 and follow my advice, and what I said last year was as different from today as today's will be from next year's. I participate on these forums to learn and share what I have learned. I get inspiration from others and new insight into old questions.

I didn't come here to pick a fight, but it looks like I landed in the middle of one. Don't take anything I have said personally. It's all in good fun.

I usually don't take things personally unless it's obvious it's meant to be. I've enjoyed our discussion so far and I'm here for the same reasons you are.
Cheers

[sphelps]

Originally Posted by Parker

I've enjoyed the back and forth banter, I've learned a lot.

I think its safe to say there is limitless ways of doing things and limitless reasons for doing them. Once you throw a human into the equation math and science can go right out the window. I know I've made some choices based on ascetics rather then what might be considered best practice.

Would definitely agree, reef tanks are more of an art form than a science. The science is the easy part but making it all come together is what makes or breaks a tank.

[mr.wilson]

Originally Posted by sphelps

External skimmers can make a big mess which is why I see a pump as a clear advantage.

I don't know what you mean by "external skimmers". I assume it's a type of protein skimmer and not a surface skimmer.

Basically I think it's fairly obvious that more return flow means more filtration. A sump is essentially a filter, bigger filters with more flow, filter more water quicker.

I see sumps as a drip catcher for filtration devices, not as filters in and of themselves. Sometimes less is more. You never gave any reasoning or linked any sources for the 10x turnover you feel so strongly about. Why not 40x if you want to do it all with one pump? That way your drain will not need to be vented and you wont get the salt spray and suction sound. There has to be reasoning why a particular turnover volume achieves a dynamic equilibrium.

A typical skimmer is independent from return flow and will essentially work the same regardless of return flow (in limits).

Very few if any protein skimmers cannot be operated on a two compartment FIFO system as I have described above. Even a becket skimmer with a high volume pump can be plumbed with the effluent line directed to a second compartment so skimmer treats new water first.

If you compare two scenarios with the first one delivering 2500 GPH to the sump drawn over a 12" x 6" overflow, then a second system where only 1000 GPH was drawn over the same overflow and delivered to a sump. The second scenario would have a higher concentration of surfactants due to a thinner film collected at the surface. It's the same argument one would make for a longer overflow box or removing the teeth from an overflow. Both scenarios keep the protein skimmer fed with fresh water. The first version moves some extra water that doesn't reach the protein skimmer. If you don't use a FIFO method, the 2500 GPH system will process the same water over and over with greatly diminished efficiency.

There are many ways to skim the cat, but you must use a method that assures that the protein skimmer is fed pre-skimmed (highly concentrated/protein-rich water) and skim it only once before returning it to the tank where it mixes with unfiltered water.

Eliminating or reducing the need for additional power heads or closed loops is also a big plus in my book and I believe it results in a simpler system. You can increase in tank flow all you want but if you're limited by return flow your filter is also limited, higher return flow will not only keep particles and matter suspended but it will also filter them out faster.

If your gola is to eliminate closed lops and power heads than you will need a 20x turnover rate, providing your flow dynamics are good, and they will be limited by only surface draining.

Not everything rises perfectly to the top of a tank and gets filtered out through the overflow in real life. Surface skimming is always going to be limited by blocks we install to prevent creatures from escaping and high total tank flow keeps things mixed up. I've also seen surface skum build up problems with lower flow tanks.

I wouldn't use teeth on an overflow for this reason. Horizontal barriers placed parallel to the overflow (above it) will keep out fish and inverts without breaking surface tension or reducing overflow surface area. Plastic gutter guard placed vertically inside an overflow box will serve the same purpose.

This is where a closed loop system offers superior flow dynamics. A return and intake can work together to build up inertia (kinetic energy). Closed loop intakes can be located in areas where detritus settles and inline mechanical filters can be used to collect it. Closed loops also offer a back-up system for flow (gas exchange) if sumps run dry, pump failure, or while you are servicing the filtration in the sump or feeding.

Using a one pump system with a 10x turnover ratio will not adequately keep detritus suspended, create ripples on the surface, keep the whole surface moving, and reach all parts of the reef structure.

Well your science isn't that scientific, it's really just an opinion based on your own experiences and some information from various sources, just like mine.

It isn't really my science, I quoted a number of very reputable sources and I showed the math. You didn't explain your experiences and you didn't show the math or even a link to the source of your magic number of 10x turnover. If you need me to back up anything I have said with scientific information than I will be happy to. I am also willing to listen if you can find fault with any of the specifics of my logic.

To me turnover means the flow turned through the sump. Pure closed loop, in tank flow doesn't really turnover anything. I prefer to practice around 10x turnover with additional in tank flow if required, many times this is not required as tank demands are based on coral species kept. I've gone into as much detail as you have on this subject, perhaps it's split between two threads but it is there. The problem is it doesn't really mean anything without evidence to back it up which is why I for one look at other peoples experiences as well rather than being blinded by my own.

The point her is simple. Why do you move water to and from your sump? The purpose is to give the filtration devices unprocessed water to clean. If your devices operate best at 3-5x the flow of the tank, then the other 5-7x you are moving is simply a juggling act. If our goal is to use our resources wisely, then we need to put more thought into magic numbers.

I appreciate that you have found this 10x formula to work best for you, but you don't have me convinced that you have had less success with 3-5x turnover or with a closed loop system (greater than 10x).

Well I for one do enjoy reading TOTM profiles, I think it's interesting to see what successful tanks use for equipment and I think a lot can be learned from other peoples experiences. Taking ideas from a group will almost always produce better results than taking ideas from one individual. I'm not sure why you would consider such a thing dishonest, perhaps the parameters aren't always that accurate but the equipment and healthy corals looks awfully real to me.

I treat TOTM's the same way I treat a show & shine car show. It's nice to see success and a well groomed finished product, but I prefer to follow the learning curve as the transmission comes out and you pass around the greasy factory manual as you come up with innovative modifications. I learn more from forum discussions about what does and doesn't work. I learn more from failures than triumphs, but it doesn't stop me from enjoying a mint TR6

Well I guess we're opposites which is probably why we get along so well , I consider myself smarter than I am experienced. I have an engineering degree and I believe I pick up things faster than most people. Where I lack personal experience I have to rely on other peoples experience to fill gaps when necessary.

I would have gone easier on you if I had known you had an engineering degree working against you

I'm not asking you to explain the logic behind a 10x turnover ratio just to be a smart ass. I would like nothing more than to be proven wrong and learn something new. Heated debates on forums are my only chance to win an argument. I don't stand a chance with a debate with my wife

[mr.wilson]

sphelps: I forgot to answer a question you asked earlier about posting my aquarium. I don't have one going right now, but I will be doing one in the January/February. I work in the aquarium industry, but mods frown on commercial posts so I don't post any pictures of my work unless they pertain to a specific question someone is asking.

[sphelps]

I’m not quoting anything from previous posts because it’s starting to turn into meaningless debates and arguments. Simply quoting selective parts of a statement and arguing only with those parts is fairly meaningless and doesn’t present any new information but rather disagreements.

An external protein skimmer is a protein skimmer that works externally (not in sump). When someone refers to “recalculating protein skimmers” for the most part these skimmers are external models. In sump models are not usually recirculating unless modified by the owner.

Really the 10x flow rate rule is common knowledge; many basic guides to saltwater aquariums will state a total flow rate of 10 times the tank volume is a good rule of thumb. My way of thinking is to start with the minimum requirement, which I believe is about 10x, then supplement more if needed and of course only if it’s practical. Remember I’m not arguing the fact that 3-5x won’t work but rather than running 10x will also work, personally I believe it may work slightly better but that’s not my main argument. If a tank was small enough and it did require 40x turnover a single pump system could be very practical. For example if you had a 20 gallon aquarium you could push 800gph through the overflow if you wanted, it would be better in my mind than putting power heads in which would just clutter up a small tank. However I would never see the need to run that much turnover in most tanks, especially smaller ones and of course it’s simply not practical to use a single pump to push 4000gph in a 100gallon tank.
As requested:

“As with any complex subject in this hobby, people are always looking for (and giving) rules of thumb. With regard to water movement in reef aquariums, many authors will advocate at least 10 times the volume of the aquarium per hour. So if you have a 100-gallon reef, you should be moving around 1000 gallons/hour. This is a fine starting point as long as you understand that this does not mean that you need to move 1000 gallons of water in and out of your aquarium.”
http://www.advancedaquarist.com/issu...3/beginner.htm

I love how the term dynamic equilibrium was mentioned because in my mind it hasn’t really been considered. One theory states that with lower return flow you’re going to end up with a higher concentration of organics in the sump however this would only be true for the beginning of the cycle and if a build up exists. Once steady state is reached a tank shouldn’t have a build up of dissolved organics, the skimmer should have already taken them out and continues to do so as more are added. Now the other approach is higher flow but less concentrated so at the beginning of the cycle it may take longer to remove built up organics but once steady state is reached the results would be the same. I’ll try and explain this again in another way; if you have two skimmers and one that takes in a higher concentration of organics but these organics are supplied at a slower rate and the second skimmer takes in less concentration however it’s supplied at a faster rate. Once equilibrium is reached the results will be the same. A skimmer will only filter out a certain percentage of organics anyway and at the end of the day no matter what the flow rate through the sump a skimmer will eventually turn over all the water eventually either way. So on one hand we have a lower flow rate that could possibly have a higher concentration but takes longer to turnover the tanks volume and on the other hand we have a higher flow rate which could possibly have a lower concentration but turns over the tank volume faster. The way I see it, these are the same at equilibrium. It’s like walking a shorter distance compared to driving a longer distance; the question is what are the speeds and distances and which one is faster.

The last thing I’ll note on this is in regards to this so called higher concentration, is that this is not something I really buy and would be very difficult to prove either way. A lower flow rate may take a thinner layer and if there was a build up of organics the concentration would be greater however at steady state there wouldn’t be a build up, otherwise you would need a new skimmer. In addition while it may be true that organics rise that doesn’t mean all the dissolved organics are located at the very surface of the water. On top of that you’ve got tremendous amount water flow in the display so it’s not really realistic to say you’ll see a higher concentration of organics at the surface of the water. As long as you have surface skimming you shouldn’t see a build up over at steady state. This is especially true for dissolved organics, since you know, they are dissolved.

I understand the FIFO method approach but it can’t actually be pulled off. Even with a 3 times turnover on a 100g tank you’re taking about 300gph which is too much for a recalculating skimmer and any other skimmer (made for 100g tank) that pulls in that much water isn’t going to skim out 100% of the organics anyway so no matter what you going to get bypass, and then going back to equilibrium as described above you’ll end with the same results regardless.

I’m not sure what is meant by horizontal barriers so I can’t comment on how effective they are unless an example is provided but I know placing netting inside the overflow may prevent creatures from entering the sump but could still result in death, more than likely they will be stuck on the net and not be able to return to the tank on there own. It’s very simple to come up with a solution for anything and everything but if it’s not practical it’s not a real solution. Most tanks use a vertical guard on the overflow that disrupts surface skimming for obvious reasons.

While closed loops have advantages, again they are not always practical. A closed loop and inline mechanical filters will add complications most aquarists would prefer to avoid. Also closed loops are not much more efficient at creating flow as a return pump because the majority of head loss results from plumbing. Most aquarists would prefer power heads on most tanks; they are easier to maintain, easier to install, more efficient, and provide substantially more options for flow dynamics. With a good turnover rate and added “kinetic energy” (which btw is related more to velocity than flow rate) from power heads you can filter out sufficient particulate matter without the use of complicated closed loops and mechanical filtration. Remember less is more
Also in regards to efficiency this can be approached many ways however I will use my tank as an example. I run a return pump and two tunze power heads, if I drop a size in return pump I’ll save 17W and loose over 500gph, if I make that up with another power head how am I saving power? I’ll actually be using about the same but I’ve added more clutter, complication and maintenance to my tank. As stated my tank uses one return pump and two power heads, the return pump puts out about 1000gph with head and is rated at 65W (although I’m sure it’s using significantly less power) and my tunzes pulse so I’ll assume an average of 3000gph at 45W combined. That’s 110W or less for a 40X turnover on a 100 gallon tank. I’d like to see less power used and better flow on the same size tank using a smaller return pump and a closed loop. But I certainly wouldn’t want to see what it looks like.

I’m not looking for math or sources to back up claims, mainly because I don’t care that much but also because I’m not disagreeing. I know may people just love to argue but that’s not my goal here. Honestly you can use pretty much whatever flow you want for a sump turnover and my argument is that it doesn’t matter. Yes lower turnover rates are quieter and for this reason more common because higher flow rates require more experience to achieve quieter results. In addition lower flow rates require cheaper internal pumps; high flow pumps are more expensive and for the most part louder.

The two main arguments aren’t really that different, one argument is for 5x and the other is for 10x, however my argument isn’t really an argument. I’m not set in my ways but rather I believe advantages and disadvantages exist for both but really we’re not talking about a huge difference here. I’m going to say something and I honestly hope it doesn’t offend anyone but from my limited experience in both this hobby and my career, I have found that too much experience can be a bad thing. The main reason relates to the old saying, you can’t teach an old dog new tricks. This holds true in many cases, lots of guys I work/deal with are extremely reluctant to change and are set in there ways. Not that their ways are necessary bad but sometimes advancement and technology provides new opportunities and methods worth trying. For example how long have people been using the Herbie style overflow? Before this style of overflow it was virtually impossible to create quiet and bubble free high flow returns so nobody did it.

I’ve said it over and over again and feel now that I’m really beating it too death but a flow rate of 3-5x will produce success and so will 10-15x there really isn’t much of a difference. Skimmers are independent and other parts of the sump filtration need to be designed for a certain flow rate. What that flow rate is, is completely up to the owner’s or maintainer’s preference and there is no real scientific evidence to support either option.


Mr. Wilson, the way you compare TOTM to show n shines is completely irrational in my books. You can fake a car; it can be really nice but not work at all. Also they really only go together in one way until you get into customizing but the same rules apply. You can’t really fake success with a marine tank, you can clean it up a little but in the end you can’t fake it. In fact most will always say it looks better in person. Why do so many people now love using T5 lighting? I can guarantee you it’s because of all those beautiful European tanks. It doesn’t mean you’re guaranteed success and the same results by using them but it sure as heck shows they work. That’s my point with TOTM, sure nothing guarantees anything but if almost all successful tanks use something it probably works pretty good or at least you can’t say it doesn’t work.

Also I did see your webpage but was hoping to see something with a little less fluff. Not trying to prove anything but I was hoping to see examples of the filtration techniques you exercise and the mature tanks that prosper from it. I only ask out of curiosity as some of your techniques both scare and fascinate me. I can guarantee that Mods won’t object to you posting some pictures of your previous tanks, whether you owned them or not it wouldn’t be considered advertisement. Plus I’m sure after 30 years you’ve owned your fair share of aquariums.

[golf nut]

I am not sure if you noticed, but if you continue to read the article from the magazine you quoted you will see the following, if you read further you might find that the writer is actually advocating against 10x through the sump rather 3x or 4x is better..

As with any complex subject in this hobby, people are always looking for (and giving) rules of thumb. With regard to water movement in reef aquariums, many authors will advocate at least 10 times the volume of the aquarium per hour. So if you have a 100-gallon reef, you should be moving around 1000 gallons/hour. This is a fine starting point as long as you understand that this does not mean that you need to move 1000 gallons of water in and out of your aquarium.
Many reef aquarists use some sort of overflow in the tank to take water to an external container called a sump. In the sump various tools such as protein skimmers, carbon containers, reactors, etc. filter the water. The water is then returned to the aquarium. This is referred to as an open loop. The volume of water that flows through this loop need only be 3-4 times the volume of the tank (not 10+). This is the filtration flow rate. The rule of thumb that was mentioned earlier refers to the circulation rate in the aquarium. This number takes into account, not only the return from the filter, but circulation from various other pumps as well. I cannot tell you how many times people have come to me and asked how they can quiet there filter down on their 90 gallon tank because they are trying to put 900 gallons/hr through their overflow.
http://www.advancedaquarist.com/issu...3/beginner.htm

[sphelps]

Originally Posted by Mr OM

I am not sure if you noticed, but if you continue to read the article from the magazine you quoted you will see the following, if you read further you might find that the writer is actually advocating against 10x through the sump rather 3x or 4x is better..

Yes I did notice, did you notice the reasoning (noise not performance) and the fact it has nothing to do with my argument or why I quoted that? Like I said before some just love to argue but I didn't say 3-5x was wrong just that it's not a requirement and 10x will work equally well if you can deal with the higher flow. Also note the date of the article.

[golf nut]

Originally Posted by sphelps

Yes I did notice, did you notice the reasoning (noise not performance) and the fact it has nothing to do with my argument or why I quoted that? Like I said before some just love to argue but I didn't say 3-5x was wrong just that it's not a requirement and 10x will work equally well if you can deal with the higher flow. Also note the date of the article.

You appear to be confirming your 10x turnover sump rate theory, however the article simply claims that 3x is adequate, otherwise they would have advocated a 10x capacity and explained how to select the correct size pipe for a silent overflow

[sphelps]

Originally Posted by Mr OM

You appear to be confirming your 10x turnover sump rate theory, however the article simply claims that 3x is adequate, otherwise they would have advocated a 10x capacity and explained how to select the correct size pipe for a silent overflow

Like I already stated, it takes more experience to run higher flows through overflows properly, it's not for everyone and it's not necessarily better than lower flow. That article is for beginners, which you would have noticed if you read the title rather than immediately trying to find something to argue with. I would never tell a beginner to use 10x turnover just like I wouldn't tell one to use a herbie overflow either.