Sunburst PLaty

Question
Hi Nicole,
We recetly got a 10 gallon aquarium(2 weeks back).We maintained the tank for a week before adding the fish.We treated the water with a conditioner and then added aqua salt after adding the fish.We had 2 Sunburst platies(1 male and 1 female)and 3 Neon tetras(sex not known). They were doing pretty well till yesterday night when we found one of the Sunburst platies(the male) dead in the tank.It was alive till the last time we fed it(which was half an hour before we found it dead). We chang water(1/4 tank once a week) and feed them twice daily with tropical crisps. This is our first time maintaining an aquarium and we have no clue what happened to the poor Sunburst platy.
I will really appreciate if you can help out here.
Thanks.
Soumya

Answer
Good evening Soumya,

This sort of unexpected death is not uncommon with fishes of this family. Lots of things could be at play, but I need a bit more information to venture a guess...

Namely, what does the water quality test at? A test kit that measures ammonia, nitrite and nitrate will be able to tell you this. 0 ppm for ammonia and nitrite is a must, whereas nitrates can be 20 ppm or for some fishes even higher without harm. If you register either ammonia or nitrite, then that explains the death of your platy - your tank is still "cycling" and the filter isn't yet mature.

Read more here:
http://freshaquarium.about.com/cs/biologicalcycle/a/nitrogencycle.htm
You can find much more about this subject using Google,
nitrogen cycle aquarium
...returns lots of results, so check that out.

Even if your tank has cycled properly, and you are only registering nitrates, livebearers are not the hardiest of fishes. They need hard, alkaline water to do well. In fact, the sort of water they like is the opposite of what neon tetras like - they like soft, acidic water - so you have a bit of an incompatibility in water preference there.

You can read more here:
http://www.wetwebmedia.com/FWSubWebIndex/poeciliids.htm

Neale Monks, an expert on livebearers and brackish water fishes, was the first to bring this to my attention - livebearers are not the "easy beginner fish" that they are touted to be at the stores. They have specific needs. For example, did you know that they are vegetarian? So do not feed regular flake to these fellas, give them vegetarian flake or spirulina flake. Also, be sure to offer vegetables. Blanched or whole, whichever you like, although if you drop them in whole then they will need a few hours (or a day) to soften up to their liking. I use a magnetic clip like those for potato chips to weigh down slices of cucumber, zucchini, squash and dark green lettuces for their grazing pleasure.

I hope that helps. Don't feel too bad about the platy, just be sure and test the water. If your tank is uncycled (showing ammonia or nitrite) then offset this by performing 50% water changes every other day. Eventually, the filter and gravel bed will mature. If your water is not fairly hard and alkaline, consider other fish - tetras, for example - since mollies, platies, guppies and swordtails (what we call the "big four" livebearers) need these conditions to thrive.

Take care!
Nicole