Desktop Fish tank - mini 27CM aquarium with caseDesktop Fish tank - mini 27CM aquarium with case
Jan 18 2014
/theme/fishtank/00-hand-operated-mini-paper-shredder/theme/fishtank/00 lid template
This project started when this exact model paper shredder fell off a shelf and broke the top pink section. I was just going to put it in the bin but then it struck me that I could have a fish tank at long last, a desktop fish tank!

To turn this base into a tank it requires a secure lid. Above is the template I created.
Using 1.5MM plastic I cut out the lid and epoxied it to the plastic base, once dry I used silicone on the inside all around the top rim to cover any potential epoxy. Making the lid fish safe, well secured and water tight so any splashes while moving the tank for cleaning etc stay inside.

For night lights I stripped a LED crystal display base to find the PCB inside was tiny. So I first tested it out on USB and then cut out a piece of heat shrink tube big enough to cover it. As the heat shrink pipe began to come in I cut out the LED hole and then went all the way. When done I added silicone to the sides and over the bulbs making it totally water proof (even under water, I tried).

I placed the finished piece on the inside corner of the tank. You can't see it unless you bend down and actually look up at it.
/theme/fishtank/7-depron scenery/theme/fishtank/8-scenery-painted/theme/fishtank/9-scenery-silicone-sealed-in-tank/theme/fishtank/11-demo-scene-lights

Instead of using loads of big rocks trying to build a scene I like I opted to make the "base" of my scene out of depron foam using silicone to glue it together. When dry I used sandpaper to sand holes and cuts into it.

Next I spray painted the whole thing dark green and then sealed it all with silicone. When everything was dry I used a few spots of silicone to hold it on the bottom of the tank.

REMOVED, was not OK for fish.
Because the tank is so small I didn't want to buy 1 meter of background from the pet store to use on 30 * 11.5CM space. Instead I added 2 carbon fibre rods epoxied to the base which are rigid but can be pulled back to slide sheets in and out. To protect the sheets I use I simply cut them to size then laminate them.
To make the case frame I used all balsa wood. The sides and lid are 2MM balsa while the base is 6MM balsa with anti-slip mat stuck to the bottom for grip.

The lid is hinged using model plane control hinges as it's what I had, they work well though. The green bottom is a moulding putty mix that comes in 2 parts when mixed together you have 15 minutes to get the shape you want. When dry its has a massive amount of grip and is also shock absorbing, perfect to sit the tank on.
When choosing plants I decided for live and not fake. This size tank can benefit a lot from a few live plants giving oxygen and also absorbing nitrates from the fish cleaning the water.

The plants come in pots normally but with the height of the tank it was not possible to keep the pots. Instead I choose a bigger rock medium for the base where I could place the roots out below the rocks to grow out. There are 2 grass type plants for fish to hide in (or it seems for the crab to also "stand on" lol) and 2 rubber type plants which are more resilient to being nibbled on by fish.
As my corner doesn't get light for most of the day from the position of our window to the sun and trees outside, at best I get 4 hours proper sunlight. This is fine for the plants but the rest of the day its still nice to see the fish lol.

I got 4 very bright LED bulbs and soldered them up in parallel (not linked together) and first added heat shrink pipe on the back of each bulb after trimming the legs down. After I use hot glue squirted inside each back of the bulb inside the heat shrink making it water proof. Now the bulbs can go in the 4 pre-drilled holes at the back.

Finally to only use 1 USB lead I soldered the night lights and day time lights up to a three way switch. Middle is off, up is night lights and down is day white lights.
I wanted to use as much of the water the fish came in to fill my tank only being 2.5L. As the crab doesn't need as much water as the fish I put that in first. It just sat there watching me for a while even after taking the photo lol.
Next two residents to join the tank are the Guppy fish. There really nice looking fish with flares of various colours all over.
The name of this fish eludes me, the closest name I could find was "Chinese VIP tail platy". They are nice fish and they really dart about sometimes, again I got 2 of these.
The Bristle nose is a member of the Plec family and love to eat algae, this was an import role to be filled and not many fish do it better. Only one of these.
Now the tank is fully populated!

Plecs to clean algae, crab to shift water and the base of the tank up helps keeps things clean and of course fish lol. 7 in total which is perfect for the size, I don't want to over populate.
The water wasn't getting any clearer after the first 24 hours and didn't want to risk build up, I went back to the pet store and got the smallest pump I could which is this "Aqua-Flow 50" which moves 100 litres/hour. The length is 14CM and my tank is 11.5CM high.. issue.
I removed the bottom filter section and placed the filter element with carbon bits center into a bag full of holes and strapped it too the bottom, now its 7CM high.
The pump is in the back left corner behind a plant, from the front you can't see it at all. I used the supplied configuration parts to put the pipe at the top and squirting sideways at the back of the tank. Doing this means most of the water simply runs down making no noise, while some droplets create bubbles into the water oxygenating it.
During the writing of this text the tank suffered issues with a contaminant of some kind, found it to be the depron base which is now removed :(. Never the less I'm still happy with the overall look of the tank.
I don't think I'm finished just yet but any further work I'll create a part 2. For example I like the idea of the crab having it's own place to venture out of the water, just not sure in what way yet.
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