Normal speed .. 4 'fishy years' till the babies are born, I believe. And a fishy year is 10 minutes ...
I always play on double speed, so it's it's four years at five minutes a year. But I also always used the magic fish that speeds this time along!
And growth hormone will help that out even more ... although sometimes it seems to abort the babies .. so is self defeating.
But when starting, with no Magic fish, and no money for growth hormone, I think 20 minutes is about as fast as it gets real time.
and I believe it's always four years fishy time.
A cool statistic I don't have on my fishie page. I'll have to test it to make sure what I 'think' is right .. then I'll get it up.