I've received a few emails from some of my friends who want to start their own little aquarium regarding the number of fishes they can have in their aquarium. Also, wondering if it is OK not to adhere to the golden rule (in setting up an aquarium): "For every inch of fish, have at least a gallon of water (for gold fish its two gallons)". I am no expert... but from what I have gathered (after talking to several aqua-experts at various pet stores and reading several books & websites), it not difficult to break this rule and yet have a healthy aquarium. Fish need four basic things to be healthy:
1. Plenty of space to swim
2. Enough oxygen in the water
3. Clean water: low ammonia and nitrite content in the water.
4. Good tank mates
The list is in no particular order. I consider all the items equally important (and assume that you have taken care of the basics like declorinating the water and setting up a heating system etc).
Contrary to what most people may believe, 'lot of food' does not appear in the above list. In fact, it is something that should comes under the 'not require' list. Let me first explain why before I move on to each of the item in the above list. Fishes don’t eat a lot and if you try to over feed them, they are going to waste most of the food. Besides, just like human, the more you eat, the more waste you produce. The best way to keep a clean aquarium is to feed the fish just enough that they don’t starve.. sounds harsh?? well that’s the opinion of most aqua-experts. Besides, if you want to enjoy your fish more, its better to see them grow slowly.. rather than have them grow to full size in a couple of months (and force you to buy a bigger tank!!).
Coming back to the items in the list. No. 1 is not hard to explain. The more space you give them.. the better they feel.. sometimes its important to choose the right kind of decorative in your tank.. some fishes are shy and like to hide behind decorative (or living) plants... other varieties like to have floating wood drifts.. some prefer dark caves... make sure you have some idea about your fish and its nature environment. A simple example is a (well maintained) zoo. You wont find animals locked in a simple iron cage.. if its a good zoo, you would probably find animals moving around in an open environment that closely matches their nature habitat. Do a simple google search about the fish you are about to buy… check for its compatibility with your existing tank mates.. little research will go a long way. I will talk about fish compatibility in more detail when I get to item no. 4.
Second item in the list. Plenty of oxygen.. not too difficult to understand.. fish breathe Oxygen (like u didn’t know that ;-) ).. if you add more fishes to your tank, make sure you have an air pump installed so that it constantly keeps the O
2 levels high. I added an air pump (with a fancy bubble) generator just so that I can try and break the rule of thumb!! I noticed air pumps (and some cool accessories) are not too expensive.. and if your tank already has a water filter along with a bio wheel, you don’t really need an air pump unless you are planning to go over the number of recommended fishes. In such cases, a smaller air pump can still do.. for example, I have a 6 gallon tank, but my air pump is meant for a 5gallon tank.. the combination of air pump and water filter/bio wheel is enough for me to have more than 6 fishes (ultimately I plan to have a total of 10.. 3 more to go at this point!!).. and you don’t have to have the air pump run all the time.. in my case, I don’t like the noise that the pump makes.. so I turn it off at night… I leave it on during the day (while I am at work).. BTW, higher O
2 levels also help the beneficial bacterial that grow in your gravel.. this means faster cleaning of all the overfed-food (and fish waste). Of course, you can rely only on the gravel bacterial.. you need to have a bio wheel or a similar arrangement.
The third item in the list… remember Nitrogen cycle.. C’mon we did this in school.. or may be high school.. it’s the cycle where we (animals) eat stuff that plants produce.. some animals eat other animals.. our waste is rich in Nitrogen which is broken down by bacteria.. which is later used by plants to produce the same items that we like to eat.. and the cycle repeats.. (well, this was a very brief introduction... I skipped several details). A similar cycle applies to a fish tank. The food that we feed them is rich in nitrogen.. the waste they produce and any un-eaten (over-fed) food gets converted into ammonia.. fishes don’t like ammonia (just like you wouldn’t like to be locked in a room filled with pee & shit!!).. this ammonia can kill your fishes if not controlled. There are several ‘good’ bacteria that like to feed on this ammonia and convert it into nitrites. Now, the nitrites are not good either… so there is another set of bacteria that take care of the nitrites and convert them into nitrate.. the nitrates is harmless to fishes (or correctly said not harmful till its concentration is way too high). If you had live plants in your tank, perhaps they would use some of this nitrate.. but assuming that you don’t, most of the nitrate gets removed when you do a water change. BTW, you can use the water from your aquarium to water you plants.. they would love it.. usually, its recommended that you should not add more than 3 fishes in a week.. or if you see the ammonia level a little high. This is because, when you add new fishes, the ammonia in the water shoots up… this triggers the growth of ammonia feeding bacteria.. remember bacteria is everywhere.. but it doesn’t multiply if it cannot find enough to eat.. so more ammonia.. more bacteria (after a few days).. so you would see a spike in the ammonia level followed by a gradual fall.. after this point, you would see a sharp increase in the nitrite level.. which again falls after a few days… once there is enough ammonia and nitrite feeding bacteria in the tank, a balance is reached and you are ready to add the next set of fishes. It is important that your tank have some kind of a bio wheel or a medium where the beneficial bacterial can grow. Never depend on the bacteria in the gravel to take care of the toxins produced in the water. Bio wheel provides a wet-dry cycle.. this helps in a more efficient disposal of waste.
Lastly, tank mates.. this is a very important criteria and many people ignore it and thus causing a lot of stress to their aqua-pets… to give you a simple example, as a zoo keeper, would you ever keep a monkey and a giraffe in the same enclosure? Or an elephant and a deer together? Definitely not. You know these animals have different life styles.. different ways of feeding.. different tastes and habitat. The same rule applies to fishes.. the sad part is most new aquarist know little about fishes.. and while at a pet store, they base their decision primarily on what they feel would look good in their tank. Its important to understand that even though a fish is classified as a community fish, it may have potential tank mate conflicts.. there are many community fishes that are bottom feeders.. if you keep them with fast moving top/middle feeders, you will starve the bottom feeders… some community fishes are more active than others.. and they tend to trouble the ones that are slow moving… in many other cases, a large size fish (otherwise peaceful) tends to chase smaller variety… in many cases, the fish behavior itself makes them bad tank mates (for example many community fishes tend to pick on fishes that have long fins.. some are fin nippers.. if you keep a Betta in such tank mates.. he will soon fall sick due to stress and die!!).. there are several websites that talk about fish compatibility.. this issues should be given due attention if you want your fishes to he happy and your tank to be a well behaved community.
If you have these four factors taken care of, then you can aim a little higher than the rule of thumb. I am going to try it.. I really hope I succeed in keeping a healthy tank with 10 fishes.
I guess, from a newbie’s point of view, this was the most useful blog I have written ;)
