Check out www.thinkfish.co.uk It has a community creator where you can create your tank. It will tell you any conflicts that could occur when you add potential new fish. It also has a good fish data base.
It is however VERY optimistic in its stocking advice. I have always felt that the combinations they suggest leave very little room for fish to swim in, and no margin at all if anything goes wrong with the filtration.
I agree, so I questioned the owner of the site and he emailed me with this reply.
The figures are correct on the stocking level calculator, although
they are much higher than you would get with old guides.
The traditional rules for stocking such as by surface area, are well
over 30 years old and don't really apply to modern aquariums
(Stocking according to surface area for instance, is based on the
amount of oxygen which can be passed through the waters surface,
which was the vital factor before powered filters were created which
agitated the surface - i.e. a long time ago!) The old formula for
stocking levels was something like 30cm of fish for every square
foot, which for example in a 4x1x1 foot (113litres) tank would give
you 120cm of stocking. If you think that 30 odd years ago, the guide
was 120cm without any decent form of filtration or aeration, you can
easily stock twice that amount with todays powerful filters.
Unfortunately, as is the case with these things, they tend to get
continually copied over and over, until everyone has the same guide,
but no-one really assesses it properly.
This old formula is based on surface area and available oxygen
supply, but does not take into account the bacterial capacity or high
flow rates (oxygenation) of modern filters. The calculator on Think
Fish does take these into account, and bases its calculations on
formulas which include factors such as the amount of protien
converted to waste in food products, amount of waste produced per
fish per cm of body length, and the bacteria carrying capacity of
surface areas associated with typical filtration medias.
As the note on the calculator states, the guide only applies to
communities of smaller fish, and where correct feeding regimes are
employed. In addition, always use the fully grown size of your fish
when working out your stocking level.
Hope this clears things up a bit, like any other formula, it is a
guide, and needs a little bit of common sense to be applied.
Think Fish
