Neon Tetra Eggs Wont Hatch?

I'm no fish breeder, however, my neon tetras laid some eggs in my nano tank over 36 hours ago. Water conditions are good ( I don't have exactly what levels everything is at) Ive kept the light off for the chance of fry hatching whilst I'm away and ive read that they are meant to hatch in 24 - 36 hours I'm now going on 48 hours without a single fry. I can see some sort of dark blotch in allot of the eggs I'm not sure what they are, can anybody help?

 

HI moo I'm not a fish breeder by any means but if you have something forming in the egg says to me that the water temperature may be a little lower than liked for them slowing up the incubation period, now I've started someone with more experience will jump in

 

thanks that could make sense as its a much cooler winter than normal where I live and I wouldn't normally require a heater

 

Neon eggs don't get a dark spot. The fry hatch out completely transparent, like tiny slivers of glass. It's hard enough to find the tiny eggs scattered about, the fry are twice as hard to spot.

 

thanks that could make sense as its a much cooler winter than normal where I live and I wouldn't normally require a heater

What is the temp in the tank? From all I have read (I am researching before trying to breed my neons) the optimal temp is about 77 degrees.

 

Optimal temperature for breeding Neons is actually 74 F. They will, however, spawn at slightly warmer temps due to the excessive breeding of the species in the Far East.