Who rates skimmers

[mr.wilson]

Originally Posted by Mr OM

Dan, if you wanted to remove a film of oil from the surface of a tank of water would you slowly add water to the tank so it comes off the surface slowly and gets caught in a sponge or would you pump it quickly.

The other way to test the theory is to take a small cup and quickly dip it into the tank, then do it again but this time submerge it a millimeter bellow the surface and you will see the surface tension isn't broken as much and water & oil is pulled from a thinner sample, over a greater surface area. You will see it pull water from several feet away.

Having a thin film overflow the surface skimmer will reduce the need for a coast to coast overflow. The best way to test the efficiency of an overflow is to place some flake food at one end of the tank and see if all of it either sinks or gets skimmed within 30 seconds. Any food that gets caught up in the middle, edges or corners means you have dead spots where films will accumulate. These oils are not only bad for water quality, they also diminish lighting intensity, and gas exchange.

[banditpowdercoat]

My coast to coast, in conjunction with the OM 4 way, no dead spots on my waters surface

[mr.wilson]

Originally Posted by banditpowdercoat

My coast to coast, in conjunction with the OM 4 way, no dead spots on my waters surface

Eliminating dead spots on the surface is another one of those details that makes a huge difference at no cost or compromise.

[sphelps]

Good points and good information there Mr. Wilson. I agree that the best skimmer design is based on recirculating counter current but of course it is a simple option and not a requirement (just like everything else). Recirculating skimmers, on average, cost double and not everyone should consider modifying there skimmers, this is not a simple modification for most. Drilling the expensive acrylic body can often result in fracture and voided warranty.

I wouldn't personally ever setup a skimmer to be fed by a siphon over a pump, in theory the perfect siphon will deliver consistent flow but in practice it's not the case and if flow is suddenly increased a big mess will exist. But that doesn't mean it can't be done, I simply don't see the benefit and wouldn't recomend it, however everyone's thoughts are different.

Moving a lot of flow through the sump has many benefits, of course so does moving little flow. It's important to remember it's not a simple science and there are many ways to skin a cat. I won't go into too much of my reasoning again but I will say real experience and evidence trumps theory. I believe that the best resource for this can be found in the RC site where every month some of the worlds best tanks are showcased and described. There you will find almost all tanks showcased run return flows around 5-10x display volume, if not more. For me it's hard to argue with success, they got to be doing something right.

You're obviously a smart guy and you have experience in aquarium design but we definitely have some differences in opinion and what we consider simple, which of course is a good thing
I also noticed you're new to this site (WELCOME BTW ), perhaps you could provide a link to your tank(s) or some of the work you've done. I always like to see the work of others who offer different approaches.

[mr.wilson]

Originally Posted by sphelps

Drilling the expensive acrylic body can often result in fracture and voided warranty.

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

I wouldn't personally ever setup a skimmer to be fed by a siphon over a pump, in theory the perfect siphon will deliver consistent flow but in practice it's not the case and if flow is suddenly increased a big mess will exist.

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"

Moving a lot of flow through the sump has many benefits

Such as...

It's important to remember it's not a simple science and there are many ways to skin a cat. I won't go into too much of my reasoning again but I will say real experience and evidence trumps theory.

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

I believe that the best resource for this can be found in the RC site where every month some of the worlds best tanks are showcased and described.

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.

There you will find almost all tanks showcased run return flows around 5-10x display volume, if not more. For me it's hard to argue with success, they got to be doing something right.

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.

You're obviously a smart guy and you have experience in aquarium design but we definitely have some differences in opinion and what we consider simple, which of course is a good thing

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

I also noticed you're new to this site (WELCOME BTW ), perhaps you could provide a link to your tank(s) or some of the work you've done. I always like to see the work of others who offer different approaches.

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.

[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 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.

[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

[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