some eggs are taking longer to hatch?

[asteria 0]

Hey guys, so I've had an accidental spawning with my ryukin girl and black moor guy, and the eggs are now hatching! I'm not sure if its due to the cold or something, but my earliest hatchings with this group was last night.... and now tonight I still have eggs that havent hatched. I know they are alive since I can see some of them moving in there, but from what I know they tend to hatch around the same time? Any input would be great, thanks! 

[blackmoors 359]

They can take up to two days difference at times.

What temp is your tank at?

[asteria 0]

Its about 68 right now. The adults are taking the 68 pretty well so I didnt think to add a heater for the fry either. Should I try to add a heater? 

[blackmoors 359]

68. Thaaaats approx 20

So should be fine.

I usually keep my eggs around 21st

Which I think issssss? 70?

[blackmoors 359]

Once free swimming add a heater to about 25c