03LightningSVT
New member
Seems your looking for someone willing to do custom work $$$. Assuming you want acrylic, you could check a few places such as a local acrylic fab shop, melevs reef, or the big auction site.
Clip on overflow teeth?
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Kyuss
Megistered Rember
It's understood how a coast-to-coast with no teeth would be ideal for surface skimming, and in most cases it's not worth the trouble to add teeth to an overflow that doesn't have already have them. But it's just a bit comical on how far some go to try and push such a trivial point. A simple "It's not worth the trouble" would be a much better point.
Yeah, that seems like a legit sales figure.
So the teeth block a large portion of the surface water and push it back down into the tank, meanwhile clean water from below the surface is being pulled right past it between the teeth? Is a clean slot going to be more efficient? Sure, but I'd wager it's not going to be anywhere as significant as you're making it out to be.
That said, a toothed overflow does still have some advantages. Take a overflow box with no teeth and a lid like DreamLand posted and put it in a tank with an eel and see how well it keeps him out of the overflow. In such a case a toothed overflow with a lid keeps any but the smallest eel (one that would fit in any overflow slot anyway) from getting under the lid and pushing up on it to gain access into it. Ask me how I know.
Yeah, that seems like a legit sales figure.
So the teeth block a large portion of the surface water and push it back down into the tank, meanwhile clean water from below the surface is being pulled right past it between the teeth? Is a clean slot going to be more efficient? Sure, but I'd wager it's not going to be anywhere as significant as you're making it out to be.
That said, a toothed overflow does still have some advantages. Take a overflow box with no teeth and a lid like DreamLand posted and put it in a tank with an eel and see how well it keeps him out of the overflow. In such a case a toothed overflow with a lid keeps any but the smallest eel (one that would fit in any overflow slot anyway) from getting under the lid and pushing up on it to gain access into it. Ask me how I know.
uncleof6
Active member
You would think so, but it is seldom going to fly, considering there are sound principles that underlay the use of a "weir," and how it affects the surface skimming/surface renewal and how those two things directly affect the health of the system. It is a science, not opinions.
I have done many long comments concerning this. The short version is on Bean's website. It is sad that the arguments become somewhat comical, because the science is the science, and is not something that can be debated or argued. Most don't understand the science, which makes it hard. It would be nice to simply say it is not worth the trouble to have teeth, but folks won't accept that. They are conditioned by marketing hype that the teeth are needed.
03LightningSVT
New member
What RocketEngineer & uncleof6 claim regarding surface renewal is technically correct. They're just splitting hairs to the nth degree when it comes to what happens with overflow boxes used on reef tanks. Ideally, with proper turnover rate through the sump and proper circulation in the display, organics will have no choice but to be suspended throughout the water column, in constant motion, not just concentrated on the surface. Given time, an equilibrium in the level of organics in the water will be reached regardless of overflow box design. How much time will be based on the devices you have deployed to remove organics. In a closed system, an overflow box does not remove organics from the water, it's merely one component of the total water circulation system.
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MrSandman
Team RC
Kyuss
Megistered Rember
I've never seen much of any science supporting just how much of a difference it makes in our application. I'm not saying it's not a more effective way to surface skim because I understand that it is, but where is the data to support that it's necessary in a reef tank? I'd be very interested to see it if it's available somewhere. I've not noticed any trend in members tanks where those with a smooth weir are different/better than a tank with a toothed overflow. I also don't think people are buying into "marketing hype" of some routed slots in acrylic as much as they are just trying to keep fish out of their overflow.
RCs very own overflow calculator on the front page tells me I only need 12 linear inches of overflow for the 800gph I run through my system, but again no explanation of how that was calculated or deemed the appropriate amount. Ask in the forums and you'll get several different answers including a C2C with no teeth - ie 72 linear inches of overflow - because "science" without any actual science.
Perfect, thanks!
dude. I use this in my sump to prevent chaeto from getting into the return chamber. my refugium is designed so that the chaeto ball tumbles evenly but it does cause loose strands to float away. The overflow teeth prevent those strands from getting everywhere. So yes, there is one good use for this. The thread can now close.
uncleof6
Active member
The physics of weirs is a solid set science. Mostly it applies to calculating flow rates of moving bodies of water, but also involves the head height behind the weir. Chemistry is also a solid science. However, removing the thinnest layer of surface water from marine aquariums, (physics,) yields the most organic rich water being fed to the skimmer, is interdisciplinary, (Physics and Chemistry.) That is because the organics are drawn to the surface of the water (Chemistry.) These sciences apply to marine aquariums, because all of the sciences apply to aquariums. Science does not change because it is an aquarium. It is not data, or science, that is absent from this hobby, it is a basic understanding of the underlying sciences, that is absent, and how those sciences trump opinions every time.
The concepts spoken about, are drawn directly from physics and chemistry. A few of us have tried time and again to explain it, but since this hobby is "supposed to be fun," physics and chemistry take the "fun" out of it. But this is the most interdisciplinary and complex of all hobbies, because it is dealing with a living system, a biological system. Without some study into these sciences, one would always be questioning, and not understanding, the why of things.
03LightningSVT
New member
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I don't often post, and while I know this is not exactly what you meant, I'd like to point out what dangerous thinking this is. The entire basis of science is that it is to be continually argued, proven, dis-proven etc. Ideas, theory, and even laws of science are to be continually challenged and investigated, you simply can't say "Well science says this so that's what it is" because for a long time , the "best" understanding of "science" said that the world was flat, until science got better and that was proved wrong. Don't just take something as 100% true and infallible because ~science~.
SoloGarth
Active member
Yes I have to agree teeth are a good thing not just a marketing gimmick. I know I have lost my clowns several times in my quanatine system which has a diy overflow made of bent acrylic and no teeth. My display has teeth and a top which prevents fish from getting into the sump. As long as you have enough flow the surface skimming aspect works just fine with or without teeth. I have tanks that are set up both ways. Just my opinion.
MrSandman
Team RC
An overflow with teeth and a proper fitting lid keep both fish and large snails out. The last thing anyone needs is a large snail getting stuck in a standpipe or a timid fish going down the overflow and perhaps into the sump where it could die, block a standpipe or get stuck in a return pump. Of course there are preventative measures one can take to minimize these "incidents" from occurring but redundancy is key when it comes to reefing equipment and if it can be achieved easily, why not?
All the science and chemistry is fine and dandy but I think the reason most people should use teeth on their overflows is to avoid issues related to what I stated above.
All the science and chemistry is fine and dandy but I think the reason most people should use teeth on their overflows is to avoid issues related to what I stated above.
uncleof6
Active member
Well it is going to be a long time before anything new shows up scientifically with aquariums, because there is no money in researching aquarium chemistry, biology, physiology, physics, what have you. The hobby is dominated by anecdote, which is just guessing, and hearsay, which is nothing but repeating what someone else said, that someone else said.
What is dangerous thinking is the belief that opinions and anecdote trump science, when it is the other way around. Even at the most basic level, folks know there are "dissolved organics" in their system, and they collect at the surface of the tank. The thicker the layer of water over the weir, the less surface water and the more subsurface water goes over the weir. Sub surface water has a lower concentration of dissolved organics. The skimmer performance is based on the concentration of dissolved organics in the influent. I will leave the rest for the inquisitive to find on their own. I have spent many hours explaining in minute detail on this forum these concepts. Homework time.
uncleof6
Active member
That is why they do it. But they do not understand the price they pay in system health. Anthony Calfo has all the data you need, concerning these concepts. It would be my suggestion, that if folks really want to debate this, they at least do some study on the topic. The only thing that will advance this hobby is science. If folks don't like science, because it isn't "easy" or simple...
03LightningSVT
New member
More Kool-Aid, thanks but no thanks. The factor that you fail to mention and consider that negates this is total system flow. Proper flow throughout the entire system (sump and display) will create a near homogeneous condition of everything in the water column, including organics.
SoloGarth
Active member
+1 I fail to see how teeth or no teeth means increased dissolved organics. Flow is independent of whether there are overflow teeth. There are many factors that are at play here. My display has teeth on it and highly turbulent water. There are no dissolved organics floating on the surface.
sleepydoc
Team RC
Here's my problem with the 'well mixed system' argument:
If you accept the fact that the dissolved organics collect at the surface, you must also accept that the highest concentration of these compounds will be at the surface in an 'unmixed' system. This being the case, the best method of removing them is surface skimming.
Now, assuming that the materials you are trying to remove are reasonably amenable to mixing, suppose you start mixing the water. At some point, they will become evenly distributed through the tank volume. At this point, it doesn't matter where you take the water from - surface, bottom, or middle.
Unfortunately, 'well mixed' is impossible to accurately measure in a practical way, so we are left guessing as to whether any given system is well mixed or not. If you have flow of 10x your tank volume, it very well may be, but no one really knows, and visual inspection is not a very accurate method of determining this. Once the mixing stops or becomes less than complete, the organics will then begin to re-accumulate at the surface. What you cannot argue, however is that the water at the surface will have a lower concentration of organics.
Thus, if you accept the assumptions stated above, you must accept that full surface skimming is at worst equal to partial surface skimming, and in the case of incomplete mixing better. Now it may be that for a given system the difference is negligible, but given the above facts, it makes sense to optimize surface skimming where you reasonably can.
Edit: it is also not difficult to prevent most fish and snails from entering a non-toothed overflow, if this is a concern, so you can have it both ways.
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Kyuss
Megistered Rember
The physics of weirs is a solid set science. Mostly it applies to calculating flow rates of moving bodies of water, but also involves the head height behind the weir. Chemistry is also a solid science. However, removing the thinnest layer of surface water from marine aquariums, (physics,) yields the most organic rich water being fed to the skimmer, is interdisciplinary, (Physics and Chemistry.) That is because the organics are drawn to the surface of the water (Chemistry.) These sciences apply to marine aquariums, because all of the sciences apply to aquariums. Science does not change because it is an aquarium. It is not data, or science, that is absent from this hobby, it is a basic understanding of the underlying sciences, that is absent, and how those sciences trump opinions every time.
The concepts spoken about, are drawn directly from physics and chemistry. A few of us have tried time and again to explain it, but since this hobby is "supposed to be fun," physics and chemistry take the "fun" out of it. But this is the most interdisciplinary and complex of all hobbies, because it is dealing with a living system, a biological system. Without some study into these sciences, one would always be questioning, and not understanding, the why of things.
I understand in practice how it's better, but I question was it a limiting factor to begin with?
Technically, a Ferrari is easily twice as fast as my car. In practice, I'm not getting to work twice as quick in one - the speed of my car isn't a limiting factor.
MrSandman
Team RC
To be honest I think we're just splitting hairs here. I still don't think the benefits outweigh the risks inherent with toothless overflows. If anyone has recommendations for preventing snails and fish from going into the overflow box without causing any other secondary issues, I'm sure readers would be interested to know what they are.
On systems with tall overflow boxes I see it as a concern.
On systems with tall overflow boxes I see it as a concern.
