Upside Down Tank

[DanK13]

Has anyone ever run an upside down tank? If so, what are the cons of it. I know one problem is maintenance of viewing area such as being able to reach to clean but due to the scope of this project its going to be large enough to get in it to perform maintenance.
Due to its location and clearances it has to be upside down for it to work. I'm pretty versed in builds but this is a new one for me. Any thoughts would be appreciated

 

[KafudaFish]

What like lights on the bottom and the reef structure is on top with corals growing towards the light like a cave?

 

[DanK13]

No, it will have lights on the top but the entry of the water is below the display pane. Kind of like when you were a kid in the bathtub and you have a cup. Submerge the cup, flip it upside down and pull it up but not break the surface of the water. The water stays in the cup even though it's above the surface.

 

[apt220]

That's over the top. Pun intended.

 

[DanK13]

I know. Its kind of a radical idea but with the space provided by the architects its the only option I have. Why they are designing the space this way I have no idea since im not an engineer but thats what they are doing. Half walls of poured concrete and such.

 

[KafudaFish]

Biggest issue would be how would you get the water into the display?

Is it being returned from a sump or are you simply turning the water over from the bottom to the top like upwelling?

 

[DanK13]

I would tap into the top of the display and have a cutout at entry to have flow match. So its kinda like having the overflow on the bottom vs the top.

 

[KafudaFish]

It is hard to picture this and I maybe seeing things differently than how you are but are you draining the tank at the bottom (your "overflow") to another area and then returning the water at the bottom as well?

If the power went out would the entire tank drain? I am picturing a bathtub with a floor drain and the water leaving it and going to another area only to return from another opening near the tub bottom.

 

[DanK13]

ill draw a quick cad so you can picture it better.

 

[Breadman03]

Just tagging along.

 

[DanK13]

rough sketch but you should get the idea.
http://i.imgur.com/54ZHY.png

 

[jong11]

Great until a seal breaks and your entire tank drains out the overflow

 

[DanK13]

either the drain side or display side would have to cause the break but there is a partition down the middle that would prevent it. I would be plenty deep enough to take the displacement of entry and exit from the tank.

 

[KafudaFish]

I saw your picture and I think it would drain very well but almost too well.

What would happen to the display water if the power was cut or even the return pump slowed down?

Would the water continue to flow out of the tank or are you thinking the cup again?

With the cup in the tub there is no air being introduced and the water stays.

We use to take a cup, fill it and flip it over on a table. As soon as someone moved it or even bumped the table it would drain.

 

[OnlyTono]

I would say this could work - it would be a similar idea to an "aqua bridge". But, you would want to flip the drain and return. The drain would have to be pump driven to hold the vacuum inside the display tank, otherwise you'll break the vacuum and all the water will drain out.

Not really sure what would happen if the pump shut off through :-/

 

[DanK13]

yeah, your right about the break dumping it. I would put in plenty of safety checks to prevent a back siphon. Though I dont know if a back siphon is really an issue if the return is up high it will only back siphon to that point.

 

[DanK13]

I saw your picture and I think it would drain very well but almost too well.

Why is it too well.

What would happen to the display water if the power was cut or even the return pump slowed down?

If the power was cut it would either 1. back siphon to the point of the return line or 2. draw water from the sump like a straw.

Would the water continue to flow out of the tank or are you thinking the cup again?

I think it kinda follows the cup idea. If you only fill the cup halfway and flip it over the air in the cup doesn't have any effect on the water still staying in there. There is downward pressure from the water wanting to down with gravity but unable to. If you puncture the top of the cup then the water would flow out but without constant flow of air it still creates a vacuum.

 

[DanK13]

I would say this could work - it would be a similar idea to an "aqua bridge". But, you would want to flip the drain and return. The drain would have to be pump driven to hold the vacuum inside the display tank, otherwise you'll break the vacuum and all the water will drain out.

Not really sure what would happen if the pump shut off through :-/

The problem i have with switching the drain and return is a back siphon. If it siphons on the "drain side" in my picture there is far less water and could cause a siphon break in the tank between sides.

 

[TundraGuy]

DanK13 these style of tanks end up being something most people wish they did not set up. Lol I know a couple. No not from leaks or catastrophic failures that land all the water on the floor. Nothing like that at all. The power gose out as long as the evaporation is kept up with your fine. It’s just that they are difficult to decorate the above surface area and keep that area clean. Now if you’re cool with fake corals and plastic plants up in there then your home free but you still have to stick your arm under the glass lip then back up into that space to change stuff out. With all that said if your still interested then lets work out the bugs.

In your drawing you have the return up in the negative pressure zone. Bad idea. If the power fails then air will be pulled in to this pipe, unless you’re using a closed loop then no worries. But in your drawing you show a zero edge for the drain to what I am assuming is a sump. The return should not be under the negative space cus lets face the reality of it we all get laze sometimes or go out of town and the ATO unit sometimes dose not function right and we blow micro bubbles from the return pump. Now if you’re using a closed loop that will work but its unnecessary and will be an eye sore so let’s move that down below and away from the negative zone. For water to move up into and back out of this zone all you’ll need is a power head of some sort pointed more or less up into that space and balm you got water flow up in the negative zone.

What I have seen in the past is a internal closed loop this removes bubbles that will collect up there. To do this you can simply run a hose/pipe from the intake of a power head to the top of the negative zone from inside the tank. This will draw water and air in and blow it out in the direction the power head is pointing. Now if you’ve ever wanted bubbles in a saltwater tank that do not cause salt creep just point the power head so it blows the bubbles back into the negative zone. The air will be pulled from the top and blown back in to the same space in a circle of air just make sure not to add so much air that the pump loses water suction. Also these bubbles will be micro bubbles and funny looking.

To get the air out of the top part is tricky but you’ll get most of it out by sucking on a hose to pull the water up in that area while your best frined pours more water in the open tank. To get the last little bit out use a pump. This method will be what limits your size you’ll have fun figuring it out. To hide you’re in tank close loop that will be up to you. But I think it would be cool to just use a drill and drill some live rock to slide over the pipe to weigh it down and use the foam method to make some fake rock structures. This could look awesome if done right. But remember when building this thing you want to be able to move this thing around somewhat to suck out stray bubbles. Now setting these tanks up you will want a sump for a place the evaporation can be controlled.

You have more questions just PM me I know some people with these types of tanks.

 

[KafudaFish]

Not a hydrologist or an engineer so I could be wrong and I hope I am.

But hydro dam often take water far below the water's surface and pump to the turbines to generate but that is one direction.

I keep looking at the picture and see the water draining over the "emergency spillway" in the back regardless of the pump.


Also there have been other discussions of using check values etc. to make sure no back siphon but the general school of thought has always been mechanical equipment can and will fail at some point.

Again I am not trying to say no way no how but it just looks difficult for this to work like everything would have to be perfect all the time and if something happened ......