The Ideal Fish Community: Compatibility Issues
by Ruby Bayan
Most tropical fish lovers and enthusiasts choose this hobby because they are giving in to the urge to accumulate wonderfully attractive and color-coordinated varieties of fish. They will often add new ones as fast as the pet store displays new deliveries. Yet in just a week's time, they will wonder why the community is failing to sustain its inhabitants.
If you are faced with this same dismal situation, don't be disheartened. With just the right know-how, you can achieve a decent level of success in maintaining an ideal fish community.
It may help you grasp the fundamentals of keeping an ideal fish community tank by first trying to imagine yourself building a miniature version of their natural environment. For your fish to flourish, they must feel comfortable in the simulated habitat you've provided. They must be "at home" enough to believe that they are in their natural environment. In other words, they should all be compatible with one another and with their surroundings.
Compatibility in a fish community involves four basic areas: water quality and temperature, food and feeding habits, behavioral tendencies, and the physical layout or aquascape. If any one of these conditions is not agreeable to every aquarium resident, the whole community might become nervous and stressed, prone to illness and possibly even die because of the problem. Therefore, itís important for us to discuss various compatibility issues in more detail.
Something in the Water
You can only maintain one environment in your aquarium - one water chemistry, one water quality, one water temperature. The fish you choose to bring together should feel content living in this one milieu you have decided to set up. You will need to do a little research on the specific types of habitats certain fish like to live in.
Some fish prefer soft, acidic water, while others prefer hard and alkaline water. There are varieties that thrive in water with low mineral content, while different ones will become sickly in such conditions. In terms of water quality, some fish require high oxygen content since they are highly sensitive to various soluble compounds and even to the slightest pollutants. Yet there are other fish with extremely high tolerance levels that can survive in the worst water compositions.
Also, a fish's preference for a specific temperature range is one of the first things you need to confirm when acquiring inhabitants for a community tank. Fish whose natural habitats are outside the established tank temperature range will be the first to get stressed and fall ill.
Like people, fish have food and feeding preferences. These preferences are dictated by several factors that must be taken into serious consideration when building a fish community.
Keep in mind that fish come in many different sizes and their mouth openings vary in size, too. A big, carnivorous fish will have no qualms about swallowing a swimmer that will fit in its mouth. On the other hand, small-mouthed fish can only nibble and swallow small pieces of food.
It is equally important to keep in mind how fast a fish can swim and eat during any given feeding session when selecting different types for your tank. Slow swimmers may be disadvantaged in the presence of fast eaters. Where the fish tend to eat is also a concern. How many are surface feeders and how many are bottom feeders? The appropriate types of food must be available to the different types of eaters. Be sure to also take into consideration whether the fish are carnivorous, herbivorous, or live-food eaters. Remember that an all-purpose fish food may not be nutritionally sensible for some members of the fish community.
Fish Conduct and Demeanor
The biggest challenge to maintaining tank harmony may be the behavioral tendencies of the various fish. As in the feeding issue, fish size must be seriously considered. Keeping a mixture of big fish and small fish in one tank, even if the big ones are not carnivorous, can lead to the miraculous disappearance of the little ones.
Hyperactive varieties co-existing with languorous types can also cause a domestic imbalance. The aggressive ones will constantly chase and harass the passive ones. The active ones will eat at their leisure while the shy and tormented ones starve behind the plants and decor.
Similar to aggressiveness, territoriality is an aspect of behavior that must be taken into consideration. Some varieties are territorial all of the time; while others only act this way when it's time to breed and care for their young. Keeping a lot of fish that hog territory and dauntlessly scare away other fish from defined areas may not be a sound strategy for maintaining an amicable community.
One other behavioral concern involves whether the fish prefer to live alone, with a mate, or in a school. Schooling fish get stressed when they are alone in a tank full of "strangers." Also, a school gets anxious when there's not enough open room to school. Some non-aggressive fish will suffer from nervous tension in the presence of predatory neighbors. Remember that stress is one of the primary causes of illness.
A Place Called Home
The last compatibility concern for the ideal fish community is the arrangement of the tank accessories and decor. As you try to simulate the natural environment of your fish, be sure to provide a suitable substrate; some fish thrive better with sand rather than gravel. You must also include adequate plants and hiding spots since shy types usually require shaded nooks for a sense of security.
Schooling fish need open space, while territorial ones need landmarks like rocks and driftwood. Nocturnals need dark, cave-like places to protect them from the light of day. If your community will be filled with many different types of fish, a larger aquarium will help you address all of the various landscaping requirements of your fish.
See also: Step-by-step Guide to Setting Up the Ideal Fish Community.