Step 1, download the 3d design and print it: https://github.com/readysetawesome/aquatic_prints/blob/main/DIY brine shrimp hatchery.stl
Step 2, you need a plastic pitcher that is almost exactly 100mm in circumference. I think this will work according to Amazon's dimensions, but it is not exactly the same as my pitcher which was found in my closet: YMMV https://www.amazon.com/Home-X-Pitcher-Design-Perfectly-Spaces/dp/B078PTPPJS/ref=sr_1_88?crid=JB2VZFQG98OE&keywords=plastic+pitcher+tall&qid=1674704435&refinements=p_36%3A100-1300&rnid=386465011&sprefix=plastic+pitcher+tall%2Caps%2C151&sr=8-88 Step 3, you need a couple things from the hardware store: extension cord lamp socket
and a wide style bulb with 7-11w of LED power Step 4 put it all together!
slip the extension plug up into the base and out through the hole near the bottom. pull the cord through completely
put the bulb threads down into the top of the stand, through the hole in the middle, and bring the socket up to meet it. Twist together completely
plug in the stand (and switch on the light if the socket has a switch)
place the pitcher into the top of the stand so it's sitting on top of the bulb
add salt water, brine eggs, aeration. Check the temperature after a while, it should be around the low 80s F given heat from the light. if the light creates too much heat, add one or more layers of aluminum foil between the bulb and the pitcher.
wait for success!