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Fishtank Tubes of Doom!


This is a journal of a project that was inspired by gerbil tracks (those little tubes that hamsters run around in) and Mrs. Andrews (a friend's mom, who encoraged me to persue the idea). Here's the plan. Fish tank + tubes = sweet fish tank! What could go wrong?
The following is what has become of this idea.


It's 2005, and I'm a junior in college. Between my studies, my abortive attempts at romance, doing preventative maintenance on my few friendships, and attempting to come to grips with my religious and philosophical views in light of a nominally sympathetic institution which nevertheless arouses my umbrage with disquieting frequency, I begin my first independent fabrication and testing project. The following is a (mostly unedited) construction journal written by the me of 2005...


The tubing has arrived! 50 feet of 1" interior diameter pvc tube. What joy! I bought this tubing (along with the parts in the box) from McMaster Carr. They sell everything! In addition to the tubing, I bought a bag of ten 1" barbed tee junctions, ten feet of half inch tubing (for my little pump) and twenty feet of 1/8" tubing (for an air pump... and just because tubing is cool!)

I decided that (after getting a nasty taste of plastic when I drank from one of the tubes) it would be a good idea to flush any chemicals I could from the tube before filling the tanks. I didn't have an adapter from 1/2 inch (the tube that fits on my pump) to 1", so I forced the half inch tube inside the one inch tube and used the pressure from the pump to force the water all the way through the pipe. In both pictures the water enters the tube on the left and leaves on the right. I had the used water draining through the emergency drain in the sink (the white 'T').
Notice the towels on the floor... It took a little work to get all of the air out of the tube... and some water came with it. Fortunately my roommates didn't immediately turn me over to the authorities for attempting to flood the room.


After a delay of several days, I finally got around to buying the "tanks". These are just cheap plastic storage containers from Walmart. I cut a few holes in them with my pocket knife and sealed the 'T's in with the silicone glue I bought from McMaster (Did I mention I bought silicone glue too?). Why didn't I just buy bulkhead fittings? Maybe because I didn't know what those were at the time. Maybe because I was being cheap. Who knows?
The credit card at the end of the smaller tank is because I cut a hole there... and then decided that I didn't actually want a hole there after all. The card was donated by my roommate, David Moore, and glued in place with more silicone glue.


It lives! Here's the prototype setup. The arrows indicate flow direction, and are color coded so you can see which tube goes where. The yellow circle on the right is to call out the air hose which is acting as the pump. An air hose can't act as a pump you say? Ahh but it can... and does rather well at it too.
The problem with centrifugal pumps (the normal submersible kind) is that they suck your fish in and chop them into little pieces of sushi... and then circulate them in your fish tank. I want my fish to be alive, but also be able to swim through all of the tubing.
An air compressor is the perfect solution. The air bubbles forced into the water will force their way to the surface, and in doing so carry the water with them. The fish are unharmed (I surmise... no testing so far) and you get great flow rates.

A little change to the design. I added a 'T' to the return pipe so that I can pump the air into the main tube without running the air tube down backwards. this way there's nothing in the way of the fish when they swim in the tubes.


Also added is a little waterfall. I discovered mostly by accident that replacing the piece of plastic that I cut out of the bottle in this way forces the water to take a circuitous route, and in the process rectifies the flow (reduces turbulence), making for a quieter waterfall.


I bought five minnows and put them in the tank. One was swimming upside down, and since everyone said he wasn't going to live long I sent him through the tubes. The fish don't like it at all. Also unfortunately the fish can get stuck in the 'T' junctions if they turn sideways at just the wrong time. The other fish are staying well away from the inlets of the tubes.

This morning when I checked on them one of the fish had been stuck under the pump... and died. One down, four to go...


So, that's all the me-of-2005 wrote. Why did I break off in the middle? Well, because the experiment ended the way you probably expected. All the fish died.

By the end of the week a fish got stuck sideways on one of the intake pipes, and died. Another leapt out of the tank onto the counter (also died). A third simply died. The last... dissapeared! At the end of the semester we found its desiccated remains while we were moving one of the desks.

So, probably the fish were too large to be comfortable being sucked down the tubes. Maybe the flow speed was too much for them. Maybe the chemicals leeching from the pipes, glue, and tanks overcame their delicate biochemistry.

I kept the "fishtank" running without any fish in it for another week, until I think the silicone joints started leaking, and I disassembled it. I kept the pieces around with the idea of re-assembling it, but without knowing what went wrong, I didn't have any good ideas what to do differently.

So What did I learn from this experiment?

Nothing I guess! Let's try again in a couple years!

Fast-forward maybe three years later. I graduated university, got a real job, moved out of my parents house, and was renting a private suite from the Bozarths. This suite had a bathroom all to itself... a bathroom with lots of counter space that I didn't need... and a couple of sinks... which would be perfect for the...

Aquarium Mk. Zwei

So werden Sie einige Änderungen dieser Ausführung bemerken. Zuerst mit meinem neuen Arbeitsplatz, konnte ich echte Schottverschraubungen leisten können! Auch konnte ich große alte Wannen statt der schnuckeligen kleinen Schuhkartons aus der Zeit vor sich leisten.

Beachten Sie auch, dass ich Schlauchklemmen bin mit, wie die Gelenke eine weitere Quelle von Lecks waren, über die ich vergessen, bis ich das Bild der Schlauchschellen sah.

The bubble pump from before is still the favorite method of circulating and aerating the water.

For fish, this time I got some "neon" I think? They're much smaller. I even let them sit in their bag for a half day to acclimate to the water temperature.

But it does no good. All but one are dead within a day. The final one lasts a week...

But ends up getting trapped in the dead-end branch of the bubble pump. Either it couldn't turn around, or it was frightened by the pump and the bubbles.

Postmortem Mk.2

After the second failure, both to keep the fish alive, and to learn anything material from the process, I essentially gave up on the idea. The tubes would prove useful in the coming years, and the tubs went back to being simply storage devices. In the end, I used the bulkhead fittings, tube, and valves for a rain-water recovery system on my garage in Everett.

In the following years the "Tube Aquarium" never caught on, mostly, it seems, due to the difficulty of cleaning the tubes themselves. Aquariums need to be cleaned? Wow, I never even got that far!

I'd still like to revisit this idea, but maybe first I'll get a normal aquarium working and learn how to take care of fish the easy way before going for the trick shot.

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