Mortality Rates

[alisdairkr]

In a typical community tank with Barbs, Neons, Guppies etc, what would be the expected 'drop out' rate in a year. (16 gallon tank with -now- about 20" of fish)
As a newbie I am still making mistakes and learning (and I suspect killing the fish). I have lost a few fish, for reasons I now understand better, but was wondering what the 'usual' mortality rate muight be for these sort of fish; assuming stats are okay.

 

[Underwurlde]

If the fish are new
If they are not diseased from source (stats & temperature)
If the water they are kept in is 'good'
Not over fed & fed a good balanced & varied diet.
Not stressed (not over lit, plenty of hidey holes)
Suitable substrate & SUITABLE TANK MATES...

Then for those fish listed they should quite happily last longer than 1 year. i.e. 'drop out rate' = none.

This is just my opionioniiononon

Andy

PS
When you say Gallon, is that US or UK. For this reason, I stick to Litres...

 

[dwarfgourami]

Very hard to specify how many fish *should* live out their natural lifespans. In theory, if you know a species has a lifespan of 4 years, and you know they were a year old when you bought them, you should then expect to enjoy their company for the next three years. Except of course, that **** happens.
Even with humans, these things are impossible to predict. Theoretically, my husband and I *should* be sure of enjoying another 40 odd years of each other's company- except that the world is full of cancers and car crashes and people being electrocuted by their fish tanks (sorry, did I make that last one up?). Most of us do know people who have died prematurely.
In the case of fish, I think it can also be said that the vast majority of them do not live out their full lifespans in nature- that was never nature's intention- but that we should be able to do rather better for them in capitivity. Still, I suspect that most fishkeepers, even the very best of them, have unexpected deaths now and then. It's if you have a lot of unexpected deaths, if you can't seem to keep fish alive for more than a few months, and if none of your fish approach a reasonable lifespan that I'd get worried.