Ng so sorry to hear that. The swallow female actually quite good (although I don't prefer swallow tails).

I liked Lai's female alot. Judging by their size we should know that it must be aggresive enough to compete for food and grow.

Vincor, there's a thing called doing to much. Sometimes it's just up to nature and your luck. If your water quality and everything is OK then let nature takes its course. I would only forsee difficulty if the guppy is left alone. It will succumb to loneliness aka stress.

And I don't mix their water with mine because I am quite confident with my water quality since Tony said his water pH is 7. When I came back just scoop them into my tank after adjusting the temperature and sleep. Never bothered to look at them after the 2 males died horribly.

If the fishes really bloated with worms, sad to say its hopeless because its internal infection which cannot be purged with any other treatment except deworm food which I had been searching quite some time already to no avail.