Neon Rabbit's 1G Pico Jar

NeonRabbit221B · Jan 19, 2020

I have been really missing my reef tanks during the week while I am salving away at work. I had previously asked me boss (through proxy of another) if I could get a nano tank for the office to which he was hesitant and the subject was dropped after my HR manager left. My goal is to build a stealth "tank" out of a 1G cookie jar for some corals, maybe some sexy shrimp and maybe a pom-pom crab. As I have spent close to 10% of my yearly salary on aquariums I have given myself 1 condition, I will use pre-purchased items with an additional budget of $75 to get this done. Attached is the picture of my $8 jar from Michaels and a photobomb of my dog.

My lighting options are a ABI LED 5050 Par 38 bulb and fixture or a DIY lighting fixture.
Heater options are open but I was thinking of a 15W betta type heater and rely on the light and ambient room temperature to keep it at 78
Flow will likely be from a small air pump of which I have several spares I got in a trade

Follow along and let me know if you have any advice!

Peace River · Jan 19, 2020

Should be interesting! I look forward to hearing how this goes - good luck!

Alexreefer · Jan 19, 2020

@brandon429 has some amazing pico reefs! He could help you in all your needs'

NeonRabbit221B · Jan 21, 2020

A little update here

I got my light stand in and some new dry rock cycling along with a few pieces of established rock ready to aquascape this weekend. I am still questioning the flow and heater because I wanted to try something different that I havn't seen before.

For the flow I was thinking about trying a magnetic stirring system similar to what you would find in a lab. A PTFE coated stirring rod could sit under a 3D printed guard to create a current. I would either build the base to have the built in magnetic rotating contraption but will likely test with my current magnetic stirring stand I use for titrations. This could be done with a small DC motor and PWM control to vary flow. Thoughts?

For heating I am torn between a junkie betta heater that is 15W or go entirely cordless and use a electric heating pad built into the base. (see line here https://www.adafruit.com/product/4308). I would likely use an arduino or pi to modulate using PWM to control the heat.

I am calling out to @Ranjib and @Schreiber for their thoughts as I may need to be talked down from a ledge on this.

Ranjib · Jan 21, 2020

A typical reef is a multi year system, I’m not sure how convenient will be the stirrer based setup. You are likely going to change or clean the equipment. 12 or 5v dc submersible pumps are cheap , I’d prefer those over stirrer , also stirrer may create vortex. With pumps you get to 3D print the nozzle and have more control over flow direction. I know folks who use just air pumps for flow in pico jars.

I like the heating pad idea very much. I worry it might be little underpowered. At less than 5watts and mounted outside I’m not sure how much difference it will make. But unless we experiment, we’ll never know.

Schreiber · Jan 21, 2020

Love the idea! Ranjib & I are mostly on the same page when it comes to thoughts on the magnetic stirrer. I've spent a lot of time around those things in labs. If you come up with a crazy way to side mount it so the flow is horizontal, I'd say you've got a feasible, albeit untested, idea. But yeah, to get any appreciable flow in there with a stirrer, you're likely to wind up with a whirlpool.

For water movement, you could definitely use a low-flow peristaltic pump outside of the tank & continuously "dose" the tank with itself.

I'm a big fan of the heating pad as well, assuming it puts out enough heat to maintain your water where you want it. It'd probably be best to power it with a relay controlled by a temperature sensor.... but it looks like the option for PWM control is there as well! You could just configure it as a light & fine tune the heating cycle you'd need to maintain an exact temperature. May be pretty tricky to go that route though.

NeonRabbit221B · Jan 21, 2020

All fair points on the magnetic stirrer idea. I was wondering if the whirlpool/vortex would be an issue and my only thought on that would be reversing the magnetic stirrer direction every few seconds. I will continue to play around with the idea but likely its shot down.

I like the peristaltic pump idea but my immediate first thought would be tubing wear. Seeing as how I have a few spares I will incorporate it into the testing though. If all else fails I will keep it with air or a small pump and 3D printed RFG.

If I can get some stuff wired up tonight I can test out the heating pad with an arduino and just see where it goes from there. Thank you both for your input!

eggplantparrot · Jan 21, 2020

what about a small 3d printed propeller glued onto the stirring rod? maybe make a round base to glue the stirring rod into and make a micro version of the Vortech pumps.

This is giving me all sorts of ideas

Ranjib · Jan 21, 2020

eggplantparrot said:
what about a small 3d printed propeller glued onto the stirring rod? maybe make a round base to glue the stirring rod into and make a micro version of the Vortech pumps.

This is giving me all sorts of ideas

That will be a tiny washing machine :0-) .
I think the alternate direction may work, may be introduce some time delay etc.. the pwm profiles in 3.0 should be able to pull this off, assuming the mechanism is controllable by pwm.

eggplantparrot · Jan 21, 2020

Ranjib said:
That will be a tiny washing machine :0-) .
I think the alternate direction may work, may be introduce some time delay etc.. the pwm profiles in 3.0 should be able to pull this off, assuming the mechanism is controllable by pwm.

pwm drive to slow way down? maybe electronic wizardry to pulse or change speeds. only problem would be a quiet motor

Fishko · Jan 21, 2020

Could go with the sicce mouse pump only 20$ on brs

NeonRabbit221B · Jan 21, 2020

The pulsing and speed changes are easily handled with PWM and a motor controller.
Going to experiment with an arduino, fan attachment and some random number generator functions

https://www.google.com/search?q=ard...i57j69i60l4.1489j0j7&sourceid=chrome&ie=UTF-8

NeonRabbit221B · Jan 21, 2020

I was on a roll today so I am just staying up late and running with the idea. I think for this build I might try and revert to my "natural" arduino state as I have no use for Wifi (can't get on my work's network through a pi due to security) and that I have probably 30-40 arduino boards of various types and sizes. If my boss doesn't let me keep the tank there then I can easily convert it back to a reef-pi build.

At 9ish volts and .75 A the heater pad hovered around 105 F which was able to bring a gallon of water to 77 F in about 3 hours. Given that I didn't let it hit steady state I am going to assume that this will be sufficent with the pad actually pressed up against the jar and having some PWM control using a MOSFET.

For the magnetic stirrer I will finish writing a script to take a value from a pot as a starting point and randomly generate values for a speed, duration and direction for the stirrer. Havn't figured out exactly how to code this yet but its part of the fun right?

Designing up my 3D models for a electronics/jar stand/Stirrer. Take a look!

eggplantparrot · Jan 22, 2020

are you making your own stirrer too?

that plate with the 2 raised circles are to hold the magnets right?

NeonRabbit221B · Jan 22, 2020

eggplantparrot said:
are you making your own stirrer too?

that plate with the 2 raised circles are to hold the magnets right?

Yup! I tested the stir plate today and I seems to work pretty well. The 3V "hobby motor" did not work for me but using a spare dosing pump sans the tubing crank and it went fantastic. My only issue to solve is that occasionally when the motor is changing direction it will toss the stir bar to the side. I might make some type of holster/mount for the stir bar per @eggplantparrot idea.

eggplantparrot · Jan 22, 2020

NeonRabbit221B said:
Yup! I tested the stir plate today and I seems to work pretty well. The 3V "hobby motor" did not work for me but using a spare dosing pump sans the tubing crank and it went fantastic. My only issue to solve is that occasionally when the motor is changing direction it will toss the stir bar to the side. I might make some type of holster/mount for the stir bar per @eggplantparrot idea.

what about sound? is the motor loud at all?