You went and got yourself a new tank. I hope you took the time to read up on cycling it. No matter what method you use for your cycle, choosing fish is the second most important part of owning an aquarium. All too often people buy fish not suitable for the enviroment they have. This article will give basic guidelines to help counter that problem, as well as help make good decisions on choosing a reliable, responsible fish store to purchase your new pets. There will be two parts to this. Part one will deal with the general things you should look for in an LFS and the fish you care to purchase. Part two will be a more advanced section on the minute details of compatability and care. Without further adue, part one: Choosing a fish store: Store cleanlyness- You walk in and the floors are dirty, shelves are dusty, and things just dont seem sanitary. This is a store you should avoid. I tend to look for a place that cares about its apearance. First impressions are important, and a clean store will show the owner cares about thier fish and thier customers. Tank cleanlyness- My favorite lfs keeps a squeegy on hand, after getting fish for you, they will clean off any water dripped on the front glass. Its those little things to look for. Are the tanks covered in algae? Is the gravel clean or are they covered in mulm? You want to get fish that are kept in good conditions from the get go. This will help ensure they are healthy when you bring them home. Store organization- I really like to be able to find things on my own. I have seen stores with a shelf full of junk, all hodge podge. Going in a few weeks later its all different. While it may seem trivial, this is another one of those small details that will show the store owner cares. A neat and organized store will get my business over those that just throw things on the shelves like they don't care. Tank stocking- We are getting into more important things here. If you chose to ignore the previous points, please do not ignore this and the following. Look for the places with well organized stocking. Look for similar fish in the same tanks. Tetras with tetras for example. South American cichlids not mixed in with African cichlids. It may take you some time to realise what fish should not be kept together, but as a basic rule, try to stay clear of places that mix a lot of fish into the same tanks. Also look to see that all the fish of a same type are together. I have seen places that have neon tetras in 5 different places. or ones that have juvenile Convicts(south american) mixed with adolescent Mbuna cichlids(africans) this is a poor practice in my opinion, as thier diets and water reqirements are different. Labled tanks- It really bothers me when I see a tank labled with fish that are no longer there. On the flip side, fish in the tank that are not on the lable. I see many threads on this forum where someone gets a fish they do not know what it is. How are you to know the proper care for this creature if you dont know what it is? Prices on the lables are also important. You know you are not getting ripped off if things are properly advertised. Fish health- A good fish store will not sell sick fish. With the volumes of fish that come through, it is inevitable they will have some casualties, and some fish that are in poor health. This is not a reason to avoid a store. If they label tanks that have issues, or keep hospital tanks for sick fish, they are trying to avoid passing the problems on to you. That is a good sign. Stay away from places that are still trying to sell fish with ich, or those that just seem unhealthy. If your Local Fish Store(LFS) has continuous problems with diseased tanks however, you may think twice about buying from them. Things to look for are white spots on the fish (ich, or fungus) sucked up bellies, deformed spines, labored breathing, or inactivity in the fish. If you cannot identify a central filtration system, ask if they use one or not. The basic definition, is a single large filter, hooked up to all the tanks, where they all share the same water. This means if the fish in the first tank have ich or some other disease, the fish in every other tank will likely have it as well. I will not buy from stores running central filtration, even if all the fish look fine. Staff- It is really hard to identify a good staff. It is best to know what you want before you go into the store. Do your own research. Read up and find factual information about the fish you want to purchase. See if the staff knows what they are talking about in relation to what your research has found. This is something that will take you some practice, but you will soon be able to identify a store with good people working for it. Choosing fish: This will cover the basics of choosing your fish. Most common fish will adapt to your tank conditions. If you plan on breeding fish, keeping aggressive fish, or some of the more water qualty sensitive fish such as discus, please refer to part two of this article for further information. Tank dynamics- This will correlate to the next few points. Please consider the dimensions of your tank, water volume, as well as temperature to ensure the fish you buy will be happy living together. You will not want to mix coldwater fish such as goldfish with tropical fish like tetras. Do not rely on the inch per gollon myth, as a 10 inch goldfish will not produce the same waste, or have the same space requirements as 10 one inch fish. Fish size- Many of the fish you will see at the store will not be full grown. This goes along with doing your research before you buy. Consider the full grown size of a fish, and not how big it is at the time of purchase. A good example is the common plecostomus. This fish can be found as small as one inch at some stores. Properly cared for it will reach sizes in excess of twenty inches. Do not fall for the "fish grow to the size of thier tank" line. Any animal will grow to the size of its environment to an extent. It will also be unhealthy, and die an early death from stunted growth. Goldfish are another commonly mistreated fish that can grow large and live a very long time with proper care. Again, please consider the adult size of the fish you would like. In general, you should allow for 3 times the adult length from fron to back of your aquarium, and at least 10 times the distance from side to side. For example, a common 10 gallon is roughly 20" by 10". This means a 2 inch fish will have 10 times its body length to swim, and 5 times its length to turn around. Fish, like any other animal, need exercise to stay healthy. This is a guideline. Some fish can do well with tanks smaller than the suggested sizes, and some fast moving fish will need more allowance than what I have outlined. Again, research before you buy, pay attention to special needs. Fish are three dimensional, and height of the fish in relation to the aquarium is also important. A four inch angelfish will need more space from top to bottom of your tank than a four inch killi or other slender bodied fish. Sociability- This is another place where you will need to do some research of individual species. There are four general categories I will outline. schooling fish- These are fish that do better in groups. I have no clue who came up with this, but 6 seems to be the common number to define a school. Fish in this group have a "safety in numbers" mentality. Neon tetras are a great example of this. A group of them will display much more pleasing behavior than a single specimen. social fish- These are similar to schooling fish. They enjoy the company of thier own kind. The difference is schooling fish will prefer to always stay together, following one anothers moves. Social fish, like the otocinclus catfish, feel safe venturing out by themselves, do not follow the group mentality, but still like to know they have a friend nearby. interspecies agressive/semi agressive- This is a rather broad general category. I could break it down further, but I am trying to keep things simple. Basically, the category is built of "iffy" choices. Care must be had when chosing them, and your own research is very important here. A single male betta may be ok in a tank with guppies, but will fight with other bettas. Gouramies also fall into this category, as a single male can be OK with other fish, but will likely kill other males of its own species. Semi-aggresive fish, like the golden killifish I currently own, may kill and eat smaller fish (like guppies) but do perfectly fine with others of their own kind, and ignore other fish of similar size. As I said, this category is "iffy". If you find something in your research labled semi-aggressive, I find it best to post in the forums for advice on what will be compatible. Agressive/solitary-The final category, again a generalization. Certain fish are solitary, they like to be alone. Most common pufferfish can be placed here. Some fish may live with them short term, but after a while will meet their doom. Utmost care is required and you must heed the advice of keeping them alone. Aggressive fish such as cichlids also need care when choosing tankmates. This is another place tank size comes in. You cannot only consider swimming room here, but must also account for adequate territory, as well as providing places for fish to hide from aggression. Many african cichlid tanks are overstocked to spread out aggression. Situations like these take experience and knowledge, as well as careful monitoring. They are not meant for the beginner. I will stress that research is the most important thing is choosing compatable fish. What I have outlined are general guidelines, and not rules. Each species has its own specific needs, and each individual fish has its own personality. Dilligence is required to ensure things will go well for the entire life of the fish. Remember, just becase your fish seem fine the first few weeks, does not mean they will still get along 2 years from now. The goal is proper long term care over the entire life of your fish. Food requrements- Very important. Not all fish can live off of flake food. This will go along with your personal research as well. Some fish need vegges, some live foods. Look into what the fish you want to keep require. When starting out, it is better to keep fish that will live off of similar foods. It is quite a task for me to target feed vegitarian fish, piscovorius fish(fish eaters) and molluscavores (snail eaters) that live in the same tank. Definately not for the novice fishkeeper. You need to learn the basics. A good example, most tetras will do well with flakes alone, and the occasional treat of a high protein item such as brine shrimp. This diet will not be suitable for highly vegetarian fish, or fish that require more live foods than the occasional snack(such as corries or dwarf puffers respectively). Tank strata in reference to fish behavior- I know what your thinking: "I bet this guy is gunna tell me to do some more research" You are correct. Fish inhabit different areas of the tank. You need to know where those are. I have over 40 fish in my 55 gallon. They inhabit the 3 main areas of the tank. Top, bottom, and middle. This is important, both to the fish health, as well as the appearance of the tank. You can't go having a tank full of catfish(well you can, but you will not have all your real estate covered). They will compete for space, and all stay at the bottom. Consider this when buying fish. Your tank will be more apealing when you have fish covering all 3 area of the tank. My 55 gallon has hatchet fish that keep to the top few inches, cardinal tetras that swim at mid level, and small catfish that keep to the bottom. It may be if you had that many fish, all of the same type, things would look a little crowded, but spreading out the species from top to bottom will give your tank a well rounded look. In closing, these are all general things to take into consideration. I cannot stress the importance of doing your own research before you buy enough. If you have any question as to compatibility, please ask in the forums before you buy, rather than getting fish as an experiment only to have them die. I will get into the more specific details in Part Two soon to follow.