Adding Fish

Do you already have a tank that's been running a while?
Or have you been out of fish for a while and you are starting again with this tank?
Or are you upgrading from a smaller tank, and if so will you be moving all the fish over and getting rid of the old tank or keeping both running?

Sorry about all those questions but the various scenarios all have different answers. If I know which one it'll saving me having to type them all out 

You said in your other thread that you've been an aquarist for 8 years, but do you know about fishless cycling? Just in case you don't know about cycling, here is an explanation
http://www.thinkfish.co.uk/forum/index.php/topic,15.0.html

What you did previously was a fish-in cycle. If you test your water for ammonia and nitrite at least once a day and do water changes as and when necessary to stop either of them from ever reaching as high as 0.25, a fish-in cycle can be done successfully. But I must confess that daily water changes on a 230 litre tank for several weeks would be a bit much for me.
If you let the ammonia and/or nitrite levels get higher than that the fish might well die, or at the very least be more prone to getting ill and will probably not live their usual life span.
If this is what you want to do, you can get fish, a few fish, as soon as the water gets to the required temperature. This is a step by step guide on how to do it with the least possible damage to the fish.
http://www.thinkfish.co.uk/forum/index.php/topic,17.0.html

There is another, more fish-friendly way to prepare the tank for fish, but it takes a couple of months. In order to grow the filter bacteria before any fish are put in the tank, you need to add a source of ammonia. This could be from a bottle of ammonia solution, decomposing fish food or a dead prawn (the kind you eat). The advantage with ammonia solution is that you know exactly how much ammonia is going into the tank; with fishfood and prawn, because they have to decompose to make ammonia, there is no way to tell exactly how much ammonia is going into the tank.
This is a step by step guide on how to do it
http://www.thinkfish.co.uk/forum/index.php/topic,16.0.html



The pros and cons:

with fish -
Pro: you can get a few fish immediately
Con: the fish could get sick or die; you will need to do a lot of water changes

fishless -
Pro: no fish get sick or die; no water changes (or at least an awful lot less)
Con: you can't have any fish for at least a month, more like two.

Whichever method you choose, you will need a test kit that tests for at least ammonia and nitrite. Liquid reagent kits are more accurate than strips and do more tests for your money.