I need help with circle type aquarium tank
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jsoong
Aquarium Advice Addict
Here's my math, & I think it is right:
Volume = pi * r^2 * d
= 3.14 * 15^2 * 7 = 4945 cu in
This is approx 21 US gal (231 cu in per gal).
Sudz - your metric conversion is wrong. There is 16.4 ml per cu in, not 2.2
DocOc - you use pi * d for area, which is the diameter equation, not area equation
However, a finished "cookie" fitting into the space will not hold the 21 gal of water. The biggest limitation is that you cannot fill such a tank to the top. The amount you can fill will be determined by the surface area of the water. If the cookie is filled to the brim, there will be zero suface area for gas exchange & your fish will die .... (This is the same reason not to fill a goldfish bowl to the brim ... ) Maximum surface area will be when the tank is half full .... You may be able to push 2/3 full (That would be roughly half the SA of half full, & approx 100 sq inches of SA). For comparasion, a standard 10 gal tank has a SA of 150 Sq in. So even though the cookie has more water than 10 gal, you really should stock it as if it is a 10 gal due to SA limitations.
To make a long story short - The most you can get in a setup like that is 15 gal or so. Plus you will have a water line somewhere in the middle of the circle .... prob not what you are imagining.
I would think that building a rectangular tank bigger than the circle opening & fitting that inside the wall would be the best - both in terms of estetics & tank volume, SA & maintanance issues. That, however, would mean tearing open the wall for installation & making some access panel for maintanance.
Volume = pi * r^2 * d
= 3.14 * 15^2 * 7 = 4945 cu in
This is approx 21 US gal (231 cu in per gal).
Sudz - your metric conversion is wrong. There is 16.4 ml per cu in, not 2.2
DocOc - you use pi * d for area, which is the diameter equation, not area equation
However, a finished "cookie" fitting into the space will not hold the 21 gal of water. The biggest limitation is that you cannot fill such a tank to the top. The amount you can fill will be determined by the surface area of the water. If the cookie is filled to the brim, there will be zero suface area for gas exchange & your fish will die .... (This is the same reason not to fill a goldfish bowl to the brim ... ) Maximum surface area will be when the tank is half full .... You may be able to push 2/3 full (That would be roughly half the SA of half full, & approx 100 sq inches of SA). For comparasion, a standard 10 gal tank has a SA of 150 Sq in. So even though the cookie has more water than 10 gal, you really should stock it as if it is a 10 gal due to SA limitations.
To make a long story short - The most you can get in a setup like that is 15 gal or so. Plus you will have a water line somewhere in the middle of the circle .... prob not what you are imagining.
I would think that building a rectangular tank bigger than the circle opening & fitting that inside the wall would be the best - both in terms of estetics & tank volume, SA & maintanance issues. That, however, would mean tearing open the wall for installation & making some access panel for maintanance.
QTOFFER
Aquarium Advice Addict
You want something that is completely contained INSIDE the 7 inch thick wall, right?
You could have a rectangular tank 30 x 36 x 7in custom built of acrylic. Why rectangular? Because of the surface area issue that jsoong brought up. This 32 gal tank would have 30 x 7 = 210 sq inches of surface area - bacause of this, you would only be able to stock it like a 15 gal. Why 36 inches high? The extra height would hide the waterline, filter output, and heater above the circular opening on both sides. Other than the expense, this tank wouldn't be difficult to build.
You would certainly have to add more vertical studs and double up the horizontal base plate and header in the space below that tank to support the weight (about 300 pounds). I would also double uo the vertical studs on either side of the tank. This would involve tearing up and replacing the wallboard on the walkway side.
You would almost certainly have to use a cannister filter because I'm sure you don't want an ugly HOB sticking out of the wall on either side. The cannister filter could sit on a shelf built in the space adjacent to the tank - behind a removable panel. You would have to find a cannister filter that would fit within the 7 inch wall space and drill a hole through the wall stud for the hoses to pass through. I notice an electrical outlet and wall switches on the wall - handy because you could tap them to power the filter and heater - might require more wallboard replacement and drilling through studs for the wiring
You would need a large vented access panel above the tank. Feeding and cleaning would likely require a stepladder and cleaning would probably be a major pain.
This would be a visually stunning one-of-a-kind setup, but in the end, you would have a difficult-to-maintain 15 gal tank for the price of a 75 gal with a lot of carpentry work thrown in too. If it were my wall, I'd get a circular piece of plexiglas with a nice stained glass applique decal for the opening....and spend all that money on a 75 gal setup to be placed elsewhere in the house.
You could have a rectangular tank 30 x 36 x 7in custom built of acrylic. Why rectangular? Because of the surface area issue that jsoong brought up. This 32 gal tank would have 30 x 7 = 210 sq inches of surface area - bacause of this, you would only be able to stock it like a 15 gal. Why 36 inches high? The extra height would hide the waterline, filter output, and heater above the circular opening on both sides. Other than the expense, this tank wouldn't be difficult to build.
You would certainly have to add more vertical studs and double up the horizontal base plate and header in the space below that tank to support the weight (about 300 pounds). I would also double uo the vertical studs on either side of the tank. This would involve tearing up and replacing the wallboard on the walkway side.
You would almost certainly have to use a cannister filter because I'm sure you don't want an ugly HOB sticking out of the wall on either side. The cannister filter could sit on a shelf built in the space adjacent to the tank - behind a removable panel. You would have to find a cannister filter that would fit within the 7 inch wall space and drill a hole through the wall stud for the hoses to pass through. I notice an electrical outlet and wall switches on the wall - handy because you could tap them to power the filter and heater - might require more wallboard replacement and drilling through studs for the wiring
You would need a large vented access panel above the tank. Feeding and cleaning would likely require a stepladder and cleaning would probably be a major pain.
This would be a visually stunning one-of-a-kind setup, but in the end, you would have a difficult-to-maintain 15 gal tank for the price of a 75 gal with a lot of carpentry work thrown in too. If it were my wall, I'd get a circular piece of plexiglas with a nice stained glass applique decal for the opening....and spend all that money on a 75 gal setup to be placed elsewhere in the house.
Hmm, I guess my hopes are running out 
. Yes you are correct I guess I should give up on such aquarium. One lost thought will it influence the surface calcs if I leave an open space above the circle from the back side where the walk way is .
. Yes you are correct I guess I should give up on such aquarium. One lost thought will it influence the surface calcs if I leave an open space above the circle from the back side where the walk way is .
Sicklid
Aquarium Advice Addict
Big Als had sphere shaped acrylic tanks, about that size once. But only a hemisphere, not a whole globe.
Anyone thinking about the surface area in a tank like this? It would only look cool if the water went all the way up, with no visible surface line, but we all know what happens then... No gas exchange=dead fish...
Anyone thinking about the surface area in a tank like this? It would only look cool if the water went all the way up, with no visible surface line, but we all know what happens then... No gas exchange=dead fish...
Lonewolfblue
Aquarium Advice Addict
oxygen said:Hmm, I guess my hopes are running out
From the backside, above the circle you could have a set of doors that can open so you can do your maintenance, etc. Could even hide shelves in the doors for your fish food, meds, etc.
jsoong
Aquarium Advice Addict
I don't see leaving an open space on top of a circle will increase your surface area. If your tank is circular & vertical, then the fuller it is past 1/2 way mark, the smaller the water surface area is. It does not matter much how much air is above the tank, it is the Air/water interface area that is important in gas exchange.
To get around the SA limitation, you would need a different shape to the tank ... may be a U-shape .... It is no accident that the popular fish tanks are all long rectangular shape - this maximize the SA per volume.
Personally, I would not put an in-wall tank in a 7" space. It is just too narrow to be easily maintained (How so you clean such a narrow tank when you can barely fit your hand in?). I would only consider an in-wall tank if you've got at least a 10-12" space, 16" even better. If you have lots of room behind that wall, you can build the wall thickness out to place a tank in (maybe some kind of closet like structure or something. But that would involve a fair amount of carpentry, plumbling & wiring, and prob cost a lot... but you will have a stunning & functional setup if planned properly.
BTW, before you even consider doing anything to the wall, make sure it is not load bearing. I would not touch a load-bearing wall without an engineering analysis.
To get around the SA limitation, you would need a different shape to the tank ... may be a U-shape .... It is no accident that the popular fish tanks are all long rectangular shape - this maximize the SA per volume.
Personally, I would not put an in-wall tank in a 7" space. It is just too narrow to be easily maintained (How so you clean such a narrow tank when you can barely fit your hand in?). I would only consider an in-wall tank if you've got at least a 10-12" space, 16" even better. If you have lots of room behind that wall, you can build the wall thickness out to place a tank in (maybe some kind of closet like structure or something. But that would involve a fair amount of carpentry, plumbling & wiring, and prob cost a lot... but you will have a stunning & functional setup if planned properly.
BTW, before you even consider doing anything to the wall, make sure it is not load bearing. I would not touch a load-bearing wall without an engineering analysis.
sudz
Aquarium Advice Addict
Well... Instead of worrying about surface area and such... Why not just put in a bubbler?
Interesting, but don't get me wrong I am not much familiar with the subject , by saying bubbler you mean adding a bubbler to the aquarium in order to satisfy the oxygen levels due to the lack of surface area or you mean creating an artistic water flow bubbler without any fish/plants inside.
Meanwhile since so far every comment suggested that the aquarium with such format filled to the top is not possible I start looking into making a paludarium instead. Not sure if it is a nice choice but it is something in between.
Meanwhile since so far every comment suggested that the aquarium with such format filled to the top is not possible I start looking into making a paludarium instead. Not sure if it is a nice choice but it is something in between.
sudz
Aquarium Advice Addict
I believe a bubbler would get sufficent oxygen in the water, to counteract the small surface area. I think it would be quite cool if you ran a bubble "wall" along one side of the tank.
I still wouldn't stock the tank heavily, espically if your prone to blackouts. The fish would NEED the bubbler.
Anywho, My logic could be flawed, Wait for more input I just saw that as an overly simple solution to the surface area/oxygen issue.
I still wouldn't stock the tank heavily, espically if your prone to blackouts. The fish would NEED the bubbler.
Anywho, My logic could be flawed, Wait for more input
I just saw that as an overly simple solution to the surface area/oxygen issue.
Sicklid
Aquarium Advice Addict
All info I have seen states that an air stone (which I think you are describing as a "bubbler") doesn't oxygenate the water at all. It simply creates an upward current in your water column, and agitates the surface of the water keeping it from building up a protein film, which prohibits the surface gas exchange we've been addressing here.
jsoong
Aquarium Advice Addict
An airstone works only by disturbing the water surface, creating ripples. Ripples has larger surface area than flat calm, so it will help.
A cascading water fall thing is much better ..... the thin film of water coming down the face creates a large SA and this is typically used in ponds for aeration. It should work in a paludarium in miniature.
Another way to create SA for gas exchange is with a wet/dry setup. You could have a hidden sump someplace with a large wet/dry. The disadvantage with this is the complexity of plumbling, and if not designed right, the risk of flooding. Plus, the sump won't fit inside the wall, so you'll need to find a room or closet to house that ..... generally sumps are only practical for large setup (or SW, where the fish/coral needs the large SA/gas exchange) ....
All of this, however, is dependent on electricity & water movement ..... so there is always a risk of fish dying with a blackout.
A cascading water fall thing is much better ..... the thin film of water coming down the face creates a large SA and this is typically used in ponds for aeration. It should work in a paludarium in miniature.
Another way to create SA for gas exchange is with a wet/dry setup. You could have a hidden sump someplace with a large wet/dry. The disadvantage with this is the complexity of plumbling, and if not designed right, the risk of flooding. Plus, the sump won't fit inside the wall, so you'll need to find a room or closet to house that ..... generally sumps are only practical for large setup (or SW, where the fish/coral needs the large SA/gas exchange) ....
All of this, however, is dependent on electricity & water movement ..... so there is always a risk of fish dying with a blackout.
sudz
Aquarium Advice Addict
so an air stone can help CO2 absorb into the water, but the same logic does not apply to the oxygen in the air?
jsoong
Aquarium Advice Addict
O2 has much lower solubility than CO2, so takes longer to diffuse across the air-water interface. Little O2 get diffused from the air bubbles before they get to the surface & is gone. The surface rippling effect is not insignificant, however. Vigourous surface aggitation can prob double your SA so an air stone will help with O2.
CO2 has much higher solubility & also chemical reaction with water, so will get into water much faster. (Plus your diffusion gradient is also much higher: 100% CO2 in your line into tank of maybe 2-3%, vs. less than 1 or 2% difference between air & water for O2.) So, more CO2 will get into the water with an airstone setup .... but to be truly efficient, you should use a reactor with the CO2 so none is loss to air.
CO2 has much higher solubility & also chemical reaction with water, so will get into water much faster. (Plus your diffusion gradient is also much higher: 100% CO2 in your line into tank of maybe 2-3%, vs. less than 1 or 2% difference between air & water for O2.) So, more CO2 will get into the water with an airstone setup .... but to be truly efficient, you should use a reactor with the CO2 so none is loss to air.
Lonewolfblue
Aquarium Advice Addict
Also, if you have the doors with storage space, I'd also recommend putting vents in the door as well, to allow air flow from the house to the tank, and moisture to escape.
sudz
Aquarium Advice Addict
Thanks for the science lesson. Just using a air stone would be too easy for him, eh? Laws of science have to be more difficult than that.
Yes I have access from behind the circle and I can make some sort of opening above the circle from behind , but I am a bit confused with what you are suggesting, I cannot picture myself how it will look like, also how big is the filter, or the layer . Anyhow it is a great suggestion some optimism after all the calcs.
after all the calcs.Similar threads
