An Over-Engineered 1-Liter Brine Shrimp Hatchery that Does It All!

Astyanax

Member
Hi guys:

Been lurking a long, long time, I figured it's time for me to give something back! While this is not exactly specific to reef-keeping, I feel there's still an application, and I hope fishkeepers of all kinds might find this interesting. :)

For almost a year, I've been hatching brine shrimp every other day for baby swordtails using the soda bottle method. While I've been mostly successful, I've found a number of small "pain points" that I would like to solve by building a more robust housing for the same method:

  1. The soda bottles need to be replaced every 6-8 uses. Making fresh caps and removing labels becomes tedious.
  2. Darkening the entire area and aiming a light at just the right spot to entice the hatched brine shrimp to go to the bottom is difficult.
  3. New LED lamps don't provide heat.
  4. Temperature inconsistencies results in 18-36 hour hatch times.
  5. Unplugging the air pump to extract shrimp can be tricky when it's the same tube for both air and water.
  6. Using the soda bottle bottom as a splash guard often results in this "lid" falling in.
  7. The whole process of extracting shrimp and setting up for a new batch takes more time than it should.
I fancy myself a little bit of a "maker" and tinkerer (I like to make cool things), so I thought this might be a fun opportunity to over-engineer a solution that solves all these problems. I hope it would also be fun to put together, and an opportunity to learn a few new skills. So I made a list of requirements:

  • The chamber must be a 1L bottle for 800mL of water, easily replaceable.
  • No more DIY bottle caps. No more label removal!
  • A 25w heater to keep the temperature in the high 80s, consistently bringing hatch time to less than 24 hours.
  • Air pump contained in the housing.
  • A permanent light for the top that is not a desk lamp.
  • An LED light for the bottom to draw the hatched shrimp down.
  • The entire chamber encased, so it can be kept dark when needed.
  • A splash cover that won't fall in.
  • Airstone instead of bare air tube, reducing noise.
  • Individual switches for each electrical component (there are 4!).
  • Dedicated spigot to decant hatched shrimp.
  • The entire rig self-contained and portable.
  • Removable panels to access any component as needed.
After some sketches and planning, I had a rough idea of how this is all going to look and work:

hatcheryV2-0-1.jpg


I'm not great with woodworking, but I do have a bandsaw, so I think I can cut all the pieces I need from hobby board from the hardware store.

Massive, massive overkill? You bet! But I'm hoping this new setup will reduce turnaround time and solve all those pain points. I'm already very deep into this project, so I will start posting progress and photos over the next few hours.

If you have any other thoughts, ideas or concerns, please chime in!

Thanks for reading,

Bill
 
After taking lots of measurements and making some more sketches, I modeled the entire housing in Google SketchUp:

hatcheryV2-1-1.jpg


The back wall will be covered, but the front and side will have removable panels (using magnets?) that will allow me to get to all the areas.

hatcheryV2-1-2.jpg
 
Here is the basic structure of the entire hatchery. The vertical walls are 3/4" poplar hobby board, sold at 3-1/2" wide at Home Depot. I only needed to cut them to length. The base is a 5-1/2" wide piece of the same stuff, and the top is a 5-1/2" wide piece of 1/4" board. Again, only cut to length!

The hole is 1-9/16" in diameter, only because that was the only forstner drill bit I had that was close to 1-1/2" in size!

hatcheryV2-2-1.jpg


To finish the support elements, I added two 1/2" square dowels to the front. All attachments were made with wood glue and 1-1/4" finish nails.

hatcheryV2-2-2.jpg


The rest of the wood elements will be framing for the access panels, as well as the panels themselves.
 
For the bottle that will serve as my hatching chamber, I chose the 1L bottle of Fiji water:

hatcheryV2-3-1.jpg


There are several benefits to this choice:

  1. It's readily available.
  2. It has a standard size mouth.
  3. The label doesn't need to be removed to see the contents unobstructed; because there is no labeling on the sides, I need only rotate it 90 degrees.
  4. It doesn't have to be washed; I can use the water that's already inside!
Before, I was making pump-friendly bottle caps by drilling a hole and gluing an airline connector in the cap. But on Amazon I found "cola bottle adapters," at less than $13 shipped for a pack of 20.

hatcheryV2-3-2.jpg


These will last me forever, and I won't need to worry about glues or other toxins getting into the water. I was getting a massive shrimp die-off after 6-8 uses; I suspect the epoxy I was using might have been leaching toxins into the water as it aged.
 
Next, I added some cross bars to begin building up the framing that will support the panels. The longer side strips are are 1/2" strips cut by bandsaw from 1/4" thick hobby board, and the short front blocks are 1/2" square dowels, all available at Home Depot.

hatcheryV2-4-1.jpg


I made sure I positioned the height of the bars just right so that they would help support the bottle, but still be as high as possible, just a tiny bit higher that the cut-off bottom (top?) of the bottle.

I also cut a piece of scrap clear acrylic to size with my bandsaw, and test-fit it on top of these bars. This will serve as my splash guard, and framing and panels will hold it in place.

hatcheryV2-4-2.jpg


I realized at this point that getting the bottle in and out will be tricky unless I cut a slot for the nozzle of the cap! I cut this out with a hacksaw.

hatcheryV2-4-3.jpg
 
Not too exciting, but next I filled my nail holes with Bondo:

hatcheryV2-5-1.jpg


After sanding those down, I put in all my vertical framing, which consisted of 3/4" strips of 1/4" board and 1/4" square dowels to finish it out. These were all secured with wood glue and clamps.

The back/side panel was cut from some crap MDF that I had, and was gllued in with wood glue and nailed in with tiny 1/2" finish nails.

hatcheryV2-5-2.jpg


Almost done with the main body; it's about to get more interesting and fun!

hatcheryV2-5-3.jpg
 
The front and side panels need to be removable. I had this idea of embedding some rare-earth magnets in the panels and frame, and then filling over them with Bondo so they'll be invisible. I found these magnets at Home Depot:

hatcheryV2-6-1.jpg


So I drilled 3/8" holes in the frame and panel boards, about 1/8" deep. A forstner drill bit enabled me to provide a flat surface for the magnets. I then superglued them in.

After this, I filled the holes with Bondo, and sanded them down flush. Once painted, they should disappear!

hatcheryV2-6-3.jpg

hatcheryV2-6-2.jpg


For a knob, I picked up these half-inch "button plugs" from Home Depot:

hatcheryV2-6-4.jpg


I attached them to the panels with #4 screws.

hatcheryV2-6-5.jpg


All three panels ready to go!

hatcheryV2-6-6.jpg


The magnets and knobs worked perfectly! The panels don't align with the frame of the box 100% perfectly, you can't tell unless you look really closely. :)

hatcheryV2-6-7.jpg


Next, I'll drill some holes for power cords and air tubing, then it's ready to paint!

Now we're all caught up to real-time. :) Thanks for reading!

Bill
 
Wow nice job following along
subscribed!
Keep on with the updates we are enjoying it.
Brilliant work, following
Wow, great work and planning! Thanks for sharing


Thank you so much for the kind words guys, I really appreciate it! I'm glad you're enjoying the build! :)

Today I'll be painting and planning out the electrical stuff.

Bill
 
Since the panels were ready, I went ahead and painted them.

Something I had to keep in mind was the fact that paint settles on different materials in different ways. It wants to soak into wood, but not filler or glue, which means it looks matte on wood and shiny on other materials. Since I was working with all those materials (plus MDF), I needed something that was more than a paint, but also a coating. So here's my Dream Team when it comes to finishing this kind of stuff:

hatcheryV2-7-1.jpg


  1. The Rustoleum 2X flat black served as a primer, so everything else would stick a little more evenly. It also gave the wood a little something to soak up first.
  2. I followed with the Plastidip, which gives everything a slightly rubberized coating along with a slightly "rough" texture. This has the effect of evening out the coating across all materials, filling some of the gaps, hiding some of my poor sanding technique, and providing a small bit of protection.
  3. Next, I sprayed again with a couple coats of the Rustoleum 2X flat black, to once again even out the color, and to protect the rubber a little.
  4. I finished out with Testors Dullcote, which is a clearcoat that protects the finish. In my experience, it is hands-down THE BEST matte clear-coat you can use on anything.
The result of all of this is a very hard "plastic" kind of finish that wipes clean with water.

hatcheryV2-7-2.jpg


Once the panels were done, I drilled holes in the housing for power cords, switches and airline.

hatcheryV2-7-3.jpg


hatcheryV2-7-4.jpg


Time to paint the housing itself!

Bill
 
Okay, the painting. So most of the day was spent in painting the main housing, using the same spray cans mentioned above. I won't take you through every grueling step, but suffice it to say my garage still smells of fumes!

Once it was done it looked pretty nice!

hatcheryV2-8-1.jpg


Now I get to work on the insides! To start, I wanted to deal with main power first. I picked up a black power cord and a 4-outlet power strip from Home Depot, both very cheap. The power cord came pre-stripped, but I had to cut the plug off and strip the wires from the power strip myself.

hatcheryV2-8-2.jpg


Next, I ran the black power cord through the hole in the back of the housing, and then soldered the wires to the power strip, matching the wire colors. I used heat shrink tubing to insulate the wires.

I have very little experience soldering, so I spent some time studying techniques on YouTube first!

hatcheryV2-8-3.jpg


After running a larger piece of heat shrink tubing over the work (I had slid it on the cord earlier!), my power cord was done and ready to drive power into the housing.

hatcheryV2-8-4.jpg


I mounted the power strip on the back-side wall of the housing using some heavy-duty double-sided mounting tape. Then I used zip tie mounts and zip ties to secure the cord to the inside walls.

hatcheryV2-8-5.jpg


I finished by applying hot glue to the hole where the power cord comes out, securing it in place and taking tension off the cord on the inside.

hatcheryV2-8-6.jpg


Done with power! Tomorrow I'll start working on hooking up the upper light.

Thanks for reading!

Bill
 
Looking good, what are the overall dimensions of the cabinet? Your attention to detail and organization is inspirational... Curious to see what your sump looks like haha
 
Looking good, what are the overall dimensions of the cabinet? Your attention to detail and organization is inspirational... Curious to see what your sump looks like haha

Heh, no sump; I'm in the freshwater world at the moment, taking a break from saltwater. Neon swordtails breeding like rabbits on baby brine shrimp! If you live in the San Diego area and want freshwater fish, come take some away!

The dimensions are 11-3/4" long, 5-1/2" wide, and 16-3/4" high.

Bill
 
The first internal component I tackled was the overhead light. I picked up one of these LED pucks from Amazon for ten bucks:

hatcheryV2-9-1.jpg


(In retrospect, I wish I had chosen the cool white instead of warm white, but this will serve just fine.)

Because I have to run cords through holes, every component in this build will have to have its cord chopped up, shortened, and wired to a switch. So I took the puck out of its outer housing, and chopped up its cord in preparation for splicing.

hatcheryV2-9-2.jpg


For switches, I had a bunch of these red/green/black push-buttons, so I decided to use them. I would have preferred rocker switches that I could "flip" on and off, but I didn't want to have to cut rectangular holes.

hatcheryV2-9-3.jpg


After soldering and heat-shrink-wrapping the one side of the power cord, I prepped it for attaching to the switch.

hatcheryV2-9-4.jpg


This is particularly tricky, because the cord has to be wired to the switch from the other side of the hole!

hatcheryV2-9-5.jpg


But once it was done and the button fully affixed to the side, I slathered a bunch of hot glue over all the exposed metal parts, insulating and securing it all.

hatcheryV2-9-6.jpg


Then I attached the cord to the zip-tie mounts with the power cord and turned it on. Igor, it's alive!

hatcheryV2-9-7.jpg


One component down, three more to go. Later today I'll set up the heater.

Thanks for reading,

Bill
 
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