Here's a couple of pics. Normally I'll add a little extension piece of PVC to the bottom of the elbow. I was just being lazy with this one.
Ingredients:
Walmart sandwich tupperware container thing (about $5)
PVC elbow
Some window screen
Rubber band
Piece of foam from a filter
4 waterproof strong magnets (could also drill small hole and use suction cups, but I prefer the option to slide it up and down and remove it easier with the magnets)
Airline tube
Air pump
Short piece of PVC pipe sized to ID of elbow
Tools:
Hole cutting bit sized to match your PVC elbow
Drill bit sized to airline tube
Drill
Your choice of tool for cutting a bigger hole (jigsaw, dremel)
Instructions:
- Cut hole for PVC elbow on one short side near the top, maybe a tiny bit smaller that outside diameter so it fits snugly
- Drill hole in PVC elbow for airline tube
- Cut rectangular opening in other short side about half way down (too low and you won't have much water left in it if you want to pull it out with fry)
- Stuff piece of low PPI filter foam in rectangular opening (don't make it too thick or too dense)
- Cover the bottom of elbow or PVC pipe extension with window screen using rubber band
- Insert elbow into hole with bottom intake inside container
- Insert airline tubing into hole (push down near bottom of PVC extension) and attach other end to air pump
- Put assembled fry saver into tank, allowing to fill with water, with top rim just a little above water line
- Fix it in place using waterproof magnets (or suction cups if you went that route)
- Breed fish and stick in fry saver when ready
When doing water changes I'll often take a spring loaded metal clamp and hold it in place to trim of tank so that when the water level drops it stays in place. There will be enough water to cover the fry if you didn't make your intake opening too low on the side. Alternatively you can just lower it down as the water level drops by sliding the magnets. Taking it out is easy - just pop off the magnets and lift it out of the tank with some water in it.
Hope that helps. They work great for me - you can stuff some java moss in there if you want. Build a few and the waterproof magnet order becomes cost effective. They can be used for a lot of things so having 10 or so on hand isn't bad.