It is very important that you buy the correct tank or fish. For example, it would be a mistake if 6, small Angelfish was bought for your small tank, when a year later they are all whooping 110 MM !! You must always think ahead.

To start with, get a good stock of fish. It does take some time for your tank and fish to settle down. I choose several Platies, which are a very hardy fish. Don't be tempted by the more exotic species at first; you could be disappointed. Make sure that when you purchase you fish, get a healthy batch. In my local pet shop, there is a quarantine tank where the unfortunate fish are having trouble. Look for those, because if the dealer does not show a quarantine tank then it might look dodgy. Also examine the fish, and point out the most healthy fish to the owner. Don't let the assistant get your a bad fish, make sure that you get the best fish you can get.

As I have already said, look for the size of the fish. What a disappoinment when he becomes too large (I haven't made that mistake YET). Because when fish are juvenile, there are all roughly the same size (juvenile with adults mixed could be misleading) and look around for an adult fish for certain.

When you have finally bought your fish, you must equalise the water It is very important, because if the fish are suddenly introduced to colder temperature it could be disastrous. Be careful, and leave the fish in the bag in the tank for 15 - 20 minutes.

When you are thinking about purchasing your fish, watch out for these points:

• Make sure that the fish are top notch material
• Never buy a fish from a tank which contains a suspiciously unhealthy looking one
• Don't buy a young fish without looking at the potential size
• Use the equalise method

   

  Requirements of the fish

  Some fish are picky little souls. Although they are good at adapting to any enviroment, its best if you get the right fish for the right aquarium:

   

• Catfishes & Labyrinth fish: They generally would prefer a broad, deep tank with plenty of water. Some fish love to hide every now and then, try to give them small hiding places.
  
• Angelfish: They are much happier if they are in tall tanks.
  
• Tetras, Danios: These fish generally like to school, and they are fast swimmers and like to race around. Give them enough space.
  
  
  

  Tank/Fish ratio

  It happens so often - a beginner stocks a new aquarium with much too many fishes, the tank becomes very toxic and you fish are all kaput. I confess, I did it as well, but not too many fish to really affect the tank. Don't forget, you can always add fish, but its harder to take a fish out, unless it is well and truly dead. This is a "Within the safe amount of fish in a tank"which will help to guide you on your first tank stocking foray. Its not the perfect formula - and water changes will be the dependant factor on whether there are high Nitrates in the end (see the "Nitrogen Cycle"). This is for any sized tank or fish:

  Length of tank * Width = Water surface area / 40 cm (standard) Now, divide the size, or the average, of the fish you want to add.

  Example:
  90(cm)* 35 (cm) = 3150(cm2) / 40 = 79 / 5(cm) = 15 fish.

  The key is to always understock as well - less fish, less waste. Say you had 14 fish instead of 18, then it obviously you won't get that extra waste in your tank. Always add fish sparingly when you start off your first aquarium (Nitrogen Cycle).