Polymate3D
Community Member
0.6L Femto Reef Aquarium:
Here is a picture of the development aquarium next to some tools to help gather a perspective of just how small this thing is.
It is smaller design of the 2.5L Pico I am working on. I chose this smaller size as it helps me to make parts quicker, but also checking how bad things like evaporation and temperature fluctuations. It is a 10x10x10cm container, but by the time you get a piece of 3D printed rockwork in there and not filling to the brim, you have 650ml of water. That's it.
Heating
Heating is being done via 2 'heating modules' These are coils of wire fitted underneath the aquarium. A single one can achieve +7c increase over ambient (19.8c ambient. 25.8c after 12 hours). I am going with 2 due to temperature loss can occur very quickly. A thermistor attached the to back off the container is measuring temperature.
Flow
I know temperature is going to be a problem, and even the heat from a internal pump is out of the question. Air pump could work but I wanted something that was a bit cleaner, so I have modified one of my 3D printed speaker motors to act like a pipette. By sucking water is and shooting it out, flow is generated. You can see this in action below:
No filtration is planned. Just cleaned up during a water change
Lighting
Lighting is custom and open to change. Currently it is using 5 small 5mm LEDs. These combined come to just 0.35W. The 5 LEDs are:
1x White 9,000K
2x Blue 465nm
2x UV 395nm
I have some concerns about not having a peak around 440nm, so if I need to change to cover this, I am ready. I have Seneye reef which literally only just fits in the container, so I captured data at the bottom, 3cm and 6cm up.
47 PAR at the base.
76 PAR at 3cm up. Likely the most important section.
168 PAR at 6cm up.
The focus on such a low volume build is soft corals, so 47 < 168 PAR seems reasonable to me.
Cooling
Planned as a addition is a Peltier based cooler fitted to the back for use in peak hot weather. The target is to be able to drop the temperature by 3 or 4c.
Controller
The micro controller running all this is Arduino based. I plan to add in functions to regulate temperature better than just on and off by learning the rating needed on average.
The entire build runs off 5V and is targeting a peak of 2A, enabling it to run off a standard 5V/2.1A USB plug. Should also enable it to run off a power bank / UPS rather easily.
Misc
The lid is a tight sealing lid. This is due to evaporation concerns, and the heating / cooling is done this way to allow this. The back and half of the sides are covered to act as insulation to stop it fluctuating so much. The base with the heating elements has a 2cm base underneath to avoid the heat being lost to the surface it is on. The pump's motor is within the lid, and so the heat from this is not put into the main aquarium.
Summary
This build is to help me learn on a bigger extreme for my 2.5L build. This one is unlikely to house any fish due to how small it is, but I have seen the Biota team mention about some small options that have worked, including a panda goby. If I do try this, I also have a 34L aquarium waiting either way.
The main focus is soft corals, with maybe a single small hermit crab and a sexy shrimp.
As with any of the above. Look forward to any questions and comments!
- Paul
