Bloated Female Guppies

Question
I have a small tank set up (5L) with two females and one male guppy.  Water ph kept around 7.2 and temp about 25 C.  All my females develop the same problem.  It starts with bloating, they look pregnant and develop the dark areas on their abdomen's that I've been told is a sign that the babies are due, however, nothing happens.  They will stay bloated for a few weeks and then will go very quiet, still eating, but not swimming around much.  Then they'll suddenly be dead or so close that I put them out of their misery.  I have gone through 4 females all showing the same symptoms.  My 5th attempt at a female has just started bloating so I am concerned.  My first male exhibited the same problem and died, but my second male so far seems immune with no problems.  The petshop doesn't seem to know what is going on, can you help at all?

Answer
Hey Prue,

It sounds like the females are aborting their pregnancies, and the dead fry are either getting stuck inside her, or the stress of pregnancy in such a small tank is leaving them so unhealthy, moderate tank conditions are preventing them from recovering.

My solution to you, is to upgrade from 5L to somewhere around 20L with the same number of fish. If you wish to add more, go with a 40L tank, and get 2 males, and 5 females. By increasing the volume, you allow more room for your female to hide and safely have her drop without interaction with other fish. Also, if a tank is too crowded, such as 3 fish in 5L, the birth of more fish will make the water ammonia and nitrite rich, and will eventually kill all your fish. Again, i'd recommend a larger setup if you wish to breed. I breed my guppies (3 male, 20 female) in a huge 155L tank. As a general rule, you want about 3L for every 2cm of fish *one guppy as an adult is typically 4-6cm*

I hope this helps out, and best wishes!