what are all the drawbacks of no overflow box?

[BeanAnimal]

I'm not debating physics, I can only imagine you are not understanding what I am saying. You can either skim the surface with an overflow box placed around a drilled hole in your tank, or you can extend a pipe from that hole to the surface and water will overflow into that pipe in exactly the same way in overflows into an ugly plastic box.

No...

The AMOUNT of surface skimming is a function of the flow and length of the weir. That is, for a given rate of flow, the longer the weir, the greater (more efficient) the effect of surface skimming.

 

[BeanAnimal]

Agreed, I think you will feel the same about the photos of my tanks above.

propeine, I don't think the only dirty water in my tank is in the top 1/32 of the tank, though I'm sure some of it concentrates there.

The "dirty water" concentrates there because it reacts with the oxygen at the air/water interace and is bonded by the surface tension. The idea is the renew this surface as quickly as possible and get the concentrated, but already dislodged organics quickly to the skimmer where than can be more easily removed.

Also, two 1.5" elbows offers almost 9.5" of linear overflow surface. You can only skim the surface so much... it's either skimmed, or not.

No... The thinner the sheet of water, the faster the surface is renewed. It is about exposing water more quikcly to the air/water interface and then getting it to the filter.

Is there a point of diminished returns? Sure... How big is the tank, what is the flow rate over the weir, etc.

The overfflow calculator on the RC home page takes a few of these variables into consideration and spits out a minimum weir length based on some basic assumptions regarding the efficiency of surface skimming and what we know about surface renewal.

This science is used daily worldwide to size weirs for wastwater treatment, aquaculture farms, treatment ponds, etc.

 

[Tmoriarty]

If you had an overflow box with 18 inches of length but only 18 1/4" slits in it you would skim less surface then a 1.5" elbow with now slits.

I think the best option is a Coast to coast with no slits to impede surface skimming.

 

[BeanAnimal]

You in fact end up with FAR LESS than 18 x 0.25" of linear weir, as the surface tension and turbulance at each tooth further impede flow and thicken the headwater. Subtract maybe 30% for the .25" teeth. That is, an effective linear weir length of maybe 3"

 

[LobsterOfJustice]

The "dirty water" concentrates there because it reacts with the oxygen at the air/water interace and is bonded by the surface tension. The idea is the renew this surface as quickly as possible and get the concentrated, but already dislodged organics quickly to the skimmer where than can be more easily removed.


No... The thinner the sheet of water, the faster the surface is renewed. It is about exposing water more quikcly to the air/water interface and then getting it to the filter.

Is there a point of diminished returns? Sure... How big is the tank, what is the flow rate over the weir, etc.

The overfflow calculator on the RC home page takes a few of these variables into consideration and spits out a minimum weir length based on some basic assumptions regarding the efficiency of surface skimming and what we know about surface renewal.

This science is used daily worldwide to size weirs for wastwater treatment, aquaculture farms, treatment ponds, etc.

So it seems we just disagree on how much "length of weir" is necessary, and where that point of diminishing returns is. I've never had a film on the surface of my water, and flake food on the surface of my water makes it to the overflow in a matter of seconds... thats renewing the air/water interface fast enough for me.

 

[BeanAnimal]

So it seems we just disagree on how much "length of weir" is necessary, and where that point of diminishing returns is. I've never had a film on the surface of my water, and flake food on the surface of my water makes it to the overflow in a matter of seconds... thats renewing the air/water interface fast enough for me.

Respectfully, we don't "disagree", as you are failing to grasp the physics in favor of insisting it is "good enough for you".

The goal was to get you to understand that while there is a point diminished returns, you are far from it, healthy tank or not. Just because you do not have a "film" or flake food clears in "seconds" does not mean you are maximizing your nutrient export mechanism aided by the surface skimming. So telling people that it is not needed, or removing an overflow box is the "next step" in reef keeping is providing misinformation.

Happy Reefing

 

[rishma]

my favorite part of having an overflow box is the ability to have a multi channel drain (herbie or Beananimal style) with a full siphon and a backup. You cannot have a full siphon and still have surface skimming.

That said, I have an external overflow box so I think I have the best of both worlds.

The noise created from traditional durso style air/water drains is unacceptable to me....but many people feel they are quiet enough.

 

[LobsterOfJustice]

Respectfully, we don't "disagree", as you are failing to grasp the physics in favor of insisting it is "good enough for you".

The goal was to get you to understand that while there is a point diminished returns, you are far from it, healthy tank or not. Just because you do not have a "film" or flake food clears in "seconds" does not mean you are maximizing your nutrient export mechanism aided by the surface skimming. So telling people that it is not needed, or removing an overflow box is the "next step" in reef keeping is providing misinformation.

Happy Reefing

This will be the my last post on the subject as I feel we are just going back and forth now.

I get the physics. I define the point of diminished returns where the extra effort or negatives outweighs the benefit. Yes, it is "good enough for me" and not "maximized." But to ugly up my tank with an overflow box to get that extra few percent of organics I'm missing isnt worth it to me. My tank, along with 99.99% of other reefkeepers, is perfectly succesful without coast-to-coast toothless overflows with BeanAnimal drains installed, despite you thinking this is clearly the only successful way to run a tank.

In fact your setup is not maximized either. Why stop at the back for the coast-to-coast overflow. Why not extend it all the way around the back and up the two sides to get even more skimming?! Or across the front of the tank too?! Or all that and a center overflow?! That would provide EVEN BETTER surface skimming.

So getting back to the original question, what are the drawbacks of no overflow box - I guess the scientific answer according to physics is that there is less surface skimming. Does it matter? In my opinion, no.

An overflow box also lets you run a herbie or beananimal style overflow which, admitedly, is quieter than my setup (in my opinion this is their only advantage). My setup is not loud but I have been told the other setups are silent. I chose visual asthetics over audible, so I can deal with a little water trickle noise to not have the overflow box taking up space in my tank.

:beer:

 

[propeine]

This will be the my last post on the subject as I feel we are just going back and forth now.

I get the physics. I define the point of diminished returns where the extra effort or negatives outweighs the benefit. Yes, it is "good enough for me" and not "maximized." But to ugly up my tank with an overflow box to get that extra few percent of organics I'm missing isnt worth it to me. My tank, along with 99.99% of other reefkeepers, is perfectly succesful without coast-to-coast toothless overflows with BeanAnimal drains installed, despite you thinking this is clearly the only successful way to run a tank.

In fact your setup is not maximized either. Why stop at the back for the coast-to-coast overflow. Why not extend it all the way around the back and up the two sides to get even more skimming?! Or across the front of the tank too?! Or all that and a center overflow?! That would provide EVEN BETTER surface skimming.

So getting back to the original question, what are the drawbacks of no overflow box - I guess the scientific answer according to physics is that there is less surface skimming. Does it matter? In my opinion, no.

An overflow box also lets you run a herbie or beananimal style overflow which, admitedly, is quieter than my setup (in my opinion this is their only advantage). My setup is not loud but I have been told the other setups are silent. I chose visual asthetics over audible, so I can deal with a little water trickle noise to not have the overflow box taking up space in my tank.

:beer:

This would be where it falls under space constraints aesthetics etc IMO. Also as you decrease surface area your gas exchange can be reduced, your air interface would be reduced as well which alleviates the need for the increased skimming.

There is a balance there. I don't know it and I'm sure you were just being sarcastic.

Hell people do fine with no skimmer, no sump etc. Doesn't make it the best possible but I have seen some nice looking tanks that way as well.

I intend on putting some GSP on my overflow or some zoas or something to kind of hide it as best I can. I left about 3/4" shelf on the front just for that reason. Won't fix my problems with flow but neither would have shortening it up. I'm content with my setup and you're content with yours and Bean is content with his and that's what its all about if you ask me.

 

[BeanAnimal]

I define the point of diminished returns where the extra effort or negatives outweighs the benefit.

The context is/was that your definition of that point and "good enough for you" are opinions. My posts in this thread were as factual as possible and in direct response to the question "what are all the drawbacks of no overflow box".

"Good enough" depends on the stocking level, husbandry and other goals. Armed with an understanding of the dynamics, one can make their OWN decision about "good enough"

Your basic premise has been to say "Getting rid of overflow boxes is IMO a simple and huge step you can do to take your tank to the next level".

is perfectly succesful without coast-to-coast toothless overflows with BeanAnimal drains installed, despite you thinking this is clearly the only successful way to run a tank.

Not once did I say or infer that a coast to coast overflow was the only way to run a successful tank, or that ANY type of standpipe system was required, let alone attempt to promote a specific design.