Guppy fries

Question
How many days after birth can i put back the guppy fries back into the main tank?

Answer
Rule of thumb is once they cannot fit in to the biggest fish's mouth and they cannot get sucked into the filter, THEN they can go back in the big tank.  This MAY take a couple of months.  It took about 8 weeks for my platys, and my largest fish in that tank are mollies.  My mollies however, since they are born bigger, only took a month to get in there.  IF you provide PLENTY of hiding spots for them, you may be able to put them in sooner.  They are pretty fast for being so little.  It all depends on your personal preference.  If you want to save them all, wait until they are big enough.  If only a few or none making it is ok, provide hiding spots and put them back in.  It's all on what you want to do about population control.

I hope this helps.  If I can help you out further, please write me back.  Lastly, the cleaner you keep their water, they quicker they will grow.  If you do a 25% water change every other day, they will grow quicker then if you only change it once a week.  Just a suggestion.  Also, feed good quality foods, including baby brine shrimp or frozen daphnia (water fleas).  This helps them grow also.

Good luck!!   ;o)