Pregnant fantail guppies died

Question
I had several fantail guppies that had their fry with no problem. The last four I had died before the fry were born.  I Can't understand why.  I always remove them from the community tank and place them in their own 2.5 gallon tank until the fry are born.   The temp. and water was fine, and the previous fish I had did great, producing many fry.  I have been puzzled by this one.  Can you help??  

Answer
Hi,
Did you cycle the 2.5 gallon tank? If not, there is probably excess amounts of ammonia and nitrite in there that are basically choking the fish to death. If it is not what, it may be some sort of other chemical, such as chlorine or chloramine which may have come through in the tap water.
You don't actually need to move the fish to a different tank when they are about to give birth, the stress of the move is enough to kill them. Just wait until the fry are born, and catch the fry in a net, and put them into a breeding net (which is in the main tank) until they are between 1 and 2cm in length, and too big to fit into the adult's mouths. Feed the fry with liqui-fry, crushed flake food and baby-brine shrimps.

Best of luck,
Kathryn