Betta Fry Problems

Question
I have been breeding Betta's for a while now and really haven't had any problems but this last spawn I've been having trouble with it is a month old now and recently they have been acting as though they have swim bladder problems but no matter what I try they are still dieing and swimming strangely
I tried fasting them for 2 days and have treated the water with fungus cure and ick cure and marycin 2 not all at once how ever I also tried feeding a small amount of peas  to them in case it was due to over feeding or constipation I have a whisper filter for a 20 gallon modified with a sponge filter to have max cleaning ability and still be fry safe in my 10 gallon bare bottom also I do 25% water change 3 times a week and I siphon the bottom every day I do use tap water that is treated and left sit which is why I don't change water every day my ph levels are in good range my gh,kh,amonia,nitrate,and all that good stuff are in good ranges any idea as to what this could be

Answer
Hi Loni,
If you never had this problem, I would call the water company and ask them if they put some new chemical in their water system.  You could also call your Pet Store Fish Manager, and ask if they had trouble with their fish lately.  This is certainly not normal, and it is very rare for one month old babies to get sick.  Mine are still on brine shrimp, and mixed food at one month, and I never had this problem.  I thinking maybe a lack of vitamins.  Never fast one month old fry, this is not good for them.  Babies are not like adults, you can never overfeed.  This is not the problem.  I would be very careful on using products on baby fish.  In fact, I would not use them.  Water changes everyday is best, and maybe adding a little Methylene Blue to their water, might help. The medication you have already given them probably made things worse.  This is strong medication for fry.
Female bettas must be very well fed before the spawn.  They need good food before, and after the spawn.  If the mother is weak, and not getting all the vitamins she needs, the fry will also be weak.  This is all I can think of...I breed betta fish, and have for a long time, and never had this problem.  I'm sorry, I cannot help you more.  When we buy females, we don't know how they have been fed.  It is best not to spawn them right away, and wait a month so that we know that they are well fed, and that the fry will be strong.
I just want to add, that the air the fry breathe must be very similar to the water temperature in their tank.  If it is cooler, they could get pneumonia, and die.  This too could be a reason.
As you know the water must be free of ammonia, nitrates, and stable PH all the time, which is why changing water everyday is so important.  
I always add aquarium salt to their tank.  This helps with fry.
Hope I have helped you
Lynda