Purchasing Fish 

Not all people selling fish know what is and isn’t healthy, so it’s up to you to inform yourself with a few guidelines.

-Are the fish free from ich spots?
-Are the fins standing upright? Or are they clamped down?
-Red streaks on fins?
-Are the selling tanks well maintained?
-Can you see rotting food or dead fish?

Even if the fish look great and can pass these few observations they may still carry diseases.   We recommend having a smaller tank, which only comes out when new fish are purchased to quarantine.   If after 4 weeks, this being optimum,  the fish seem fine, you can add them to the main aquarium.  We know not everyone can do this, but this is the best way to protect your own fish.  For those people who can't, we recommend emptying the fish bag into a clean bucket and slowly adding the aquarium water at intervals to the bucket.  Make sure never to let the bucket get too cold.  After 20 minutes you can then scoop the fish with the net and carefully drop them into the main aquarium without letting the net touch the water.  Sounds like a lot, but better safe than sorry.

Never overdo it when you start your aquarium with your first fish.  In a 33 gallon aquarium, you'd probably only begin with 5 to 7- 2 " fish.  Make your choice wisely because you will have to let the fish cycle the water for themselves which takes about a month. This means that all the bacteria has to be at the right levels to be able to support more fish.  Never double the population at any time.  Bacteria needs time to grow in order to eat away at ammonia that increases when  adding new fish.   Most aquarium stores will do free water tests.  Unless you have your own kits at home, take a water sample to the store with you when you  plan to purchase new fish.  Even if you think the water "looks" great,  things may not be.  {Carbon monoxide is also invisible.}
The bigger the better.  Small fish do not belong in small aquariums.  They need room to swim.  Larger tanks disperse more ammonia and toxins if problems do arise, therefore are much easier to maintain.  We recommend no smaller than a 36” tank but a 48” aquarium is better.  Remember to check the floor supports to see if it can handle the weight of the aquarium plus all that water.  Water doesn't quite weigh 10 lbs/ gallon, but figuring this into your equation makes it easier to "guestimate".   Ask your self what kind of fish you wish to enjoy and proceed from there.