Have yet to complete testing to see how well it works but the basic principle is sound
I need some newly hatched shrimp to feed my Fry so i went the Blue Peter route and made my own Hatchery.
The components are very basic and most of them you probably have lying around.
1. 2 ltr Plastic Bottle (lemonade, cola etc)
2. 1 Small Air Stone, Air line and Pump
3. 1 Heater (the juwel type are ideal)
4. 1 Large plastic container big enough to hold the heater and Bottle
5. Some Basic Tools and Aquatic Silicone Sealant, Optional Gravel.
The 1st job was to cut the bottom off of the Bottle:
Then drill a hole in the bottom piece large enough for Air line to pass through:
Then drill a hole in the lid of the bottle just big enough for the air stone tip to pass through, add a bead of silicone sealant and press the Air Stone into the lid, this pic is for illustration after this i used a socket to hold the piece in the vice while the silicone set:
Then add a bead of sealant around the bottom of the air stone and screw the lid on the bottle (leave to set):
Then cut the top off of the container so the bottle, air line and heater cable can fit in nicely, i added some gravel in the bottom of the container for the bottle to rest on but as the level of water needed in the container had to cover the heater the bottle floats anyway:
Side Note - The hole in the bottom of the bottle was for the airline to pass through so the upturned bottle could be seated in the bottom to stand it on the gravel as it turned out the bottle floated anyway and this wasn't necessary but the option is there for tweaking the set-up, maybe you'll stand the bottle in an old tank where the heater will lie lower and the bottle will sit on the bottom, i'm just offering the basic idea.
Next connect the air line to the air stone and lower the bottle into the container which is then filled enough to cover the heater as said before and a Pint of water was placed into the Bottle, when the temp reaches approx 30 Celsius or 86 Fahrenheit (guidelines from Shrimp Egg Bottle) add salt to the water in the bottle then add the eggs and away you go.
Up and Running (minus eggs)
I may need a more powerful pump to really disturb the water and tumble the eggs, will have to see. i also placed a plastic bag loosely over the top of the bottle to prevent condensation.