My unusual aquarium

http://jasonlpsmith.googlepages.com/ I built this aquarium in June 2007. The tank is unusual since the fish are able to swim above the apparent water level.

I keep getting the same question or comment: What happens if the power goes out. Answer: Nothing. As stated in the video, the pump is a diaphragm pump. It has build in one-way valves, so the water will stay put when the pump is off. I only turn on the pump for water changes, it is off most of the time.

The tank was constructed with 4.5mm acrylic, the pump is a flopump FL-2202 diaphragm pump.

There is some more information on my website including a technical drawing which I created to laser cut the acrylic.

I got the idea from the bottled water dispensers which have a large bottle upside down. Others that have done it have called it open bottom, inverted aquarium and romaurie effect.

Music: Saint-Saëns, "The Carnival of the Animals", movement 7 "Aquarium".

Category:

Howto & Style

Tags:

• Aquarium
• unusual
• fish
• tank
• negative
• pressure
• open
• bottom
• inverted

[webnician]

I've thought about this for years and finally went looking. I have yet to find an answer to several questions: How much negative pressure can the fish take? Would a fish swim high enough to harm themselves or do they instinctively avoid it?

[jasonlpsmith]

@webnician I am not sure how much negative pressure they can handle, it probably differs between species. The top water level is about 0.3m above atmospheric pressure water level, so the pressure difference is about 3kPa. A 3kPa difference in air pressure is approximately a difference in altitude of about 800m. I think a fish in a lake 800m altitude would be the same as the top of this aquarium near sea level.

[jorasave]

is awesome!! do you have a valve that prevent the air go in if the power shots down?

[jasonlpsmith]

@jorasave Thanks. The pump has two one-way valves built in (it is a diaphragm pump). I keep the pump off most of the time since it is noisy.

[leannvlewis]

Would you be able to make and then post a video about how your filtration and pumps work, and how they're placed?

Thanks & Congrats on having such imagination.

[jasonlpsmith]

@leannvlewis Thanks. I used an Eheim internal filter that was a little bit oversized for the tank to keep the water in constant motion to prevent stagnation of the water at the top and keep the oxygen level in equilibrium with the air. I put the filter at the bottom of the tall section to keep the water moving everywhere in the tank.

[jandocky]

excellent tank although you didnt need to have a hole at the top just put an airline with a float up through the bottom and just suck the air out as you fill with water. would like to see the other design you had made

[5teampunker]

Awesome tank and nice video

[junioribanez66]

if your power goes off you're fucked !!

[idiot12494]

That is an awesome tank, superb job on it and the plants add a really nice look.

[ookachaka10]

I've done this before. It uses an upside down tank concept