EDIT: It looks like the SF Hatch Mix packets already have salt in them. If that is the case, and you added it to Mark's recipe you may well have been at double the target salinity . You might try significantly diluting it and seeing what happens, although I'm not sure what shape the eggs will be in at this point. Aim for 1.018.The recipe I use is below (source: http://www.brineshrimpdirect.com/res-hatching-c169.html). I also get my brine shrimp cysts from them. Have been using the same container for years, kept in the freezer long term, then moved to the fridge which I pull from. My hatchery also came with the SF eggs, I remember a very poor hatch rate, but not nothing. I can give you a batch of known good eggs if you want.Recipe:1 2/3 tbsp salt, 1L water, 1/4 to 1/2 tsp water. My house temp is 78-80, so I don't worry about temperature. My hatchery is a 2L bottle with the airline coming in the bottom.I would rinse (tap is fine) your 2L bottle just in case soap or something got in it. Between batches I wash mine with dish soap, then rinse with tap water until clear. I would also make it from scratch rather than using tank water. It seems pretty unlikely that there is an issue in the tank water, but it is another variable.