If you visit your local aquarium store you might be overwhelmed by the number of bottles, bags and tablets available for your fresh or saltwater system. These products are designed for a lot of different uses in the tank. You should be familiar with any product you introduce, know how to use it properly, what side effects to expect and if it will be harmful to any of your fish. Don't be too intimidated, most of these products fall into four basic categories: conditioners, supplements, filtration and medications. Use the fewest number of products you can to maintain your tank. There is still no substitute for regular tank maintenance, which prevents most water and disease problems.
The tap water you use to fill your tank is treated with a variety of chemicals to ensure its safety for drinking. These additives vary within communities, depending on local needs and ordinances. Most often, chlorine and chloramine are used. Both are toxic to fish. Chloramine is a chlorine compound that also contains ammonia. If you use well water, hard minerals, sulfur and other contaminants may exist. Have your well tested and the report will indicate any concerns. Once you know what's in your water supply, you can choose a product that will remove specific toxins.
Dechlorinators remove chlorine and chlorine compounds from tap water, making it immediately safe to use. Water conditioners add salts and small amounts of mineral to the water along with chlorine removers. Conditioners also help your filters work more effectively by binding some toxins, making them easier to remove. The salt helps fish secrete a thicker slime coat, which often protects them from contracting skin parasites and adds protection for wounds. These conditioners are different than the amount and type of salt used in a marine aquarium.
If your water has developed a problem that needs to be corrected, like a rise in ammonia levels or cloudy water, there are a number of products available to help restore your tank to a healthy balance. These products are often used in conjunction with your filter system and are most commonly found as bags of mineral chips or synthetic beads that will help pull contaminates out of the water. Activated charcoal and ammonia chips are two examples. Placed in the filter system, the water will flow over these porous chips, which will bind the toxins. Some hobbyists use these bags as a regular part of their tank filtration to keep the water sparkling clean. Synthetic adsorbents work well to remove proteins, nitrites and other mineral contaminants. Synthetic products are more expensive, but they often last longer and have a higher absorptive capacity than activated carbon alone. There are products available to remove phosphates, copper, nitrogen wastes, and heavy metals that may be in your water.
Delving further into the store shelves you will find a vast array of additives that are designed to benefit your tank in many ways. Most of these supplements are manufactured for use in saltwater aquariums where the marine environment is harder to re-create and much of the sea life will have special environmental requirements. Read labels carefully to make certain you are not doubling up on certain trace minerals or other elements when you use more than one product. Weeding through all the bottles, you may come to find what is called a "starter culture." This is actually a bottle of the types of bacteria needed to balance the nitrogen cycle in your tank. Your tank will do this on its own in about 3 weeks after your first fish is added, but if you are in a hurry or want to add fish at a faster rate than normal a starter culture will get the nitrogen cycle running in a few days. Both marine and fresh water cultures are available.
Mineral supplements are designed to add small amounts of trace elements to the water required by marine organisms. Magnesium, strontium, iodide and calcium are a few that may be lacking in your tank. The addition of these elements depends on the type of tank you keep. A reef tank with live rock and a number of invertebrates will require more attention to supplementing the water than will a species tank of damsel fish. Keep this in mind when you set up a marine tank so proper care of your fish doesn't exceed your budget.
Besides water quality, when fish get sick it is usually due to one of four reasons: parasites, bacteria, fungus or viruses. Fish disease can be hard to diagnose and fish can often be sick for a very long time before you notice anything is wrong. This is where you have to be very careful in selecting a medication. The first step in treating any sick fish is to isolate it in a hospital tank. Remove it from the show tank and place your patient in a plain 10-gallon aquarium (larger if the fish is bigger) with a heater and an airstone. Use medications only in the hospital tank. Your aquarium is a delicate balance of many types of bacteria that help break down waste products. Using antibiotics can upset this balance. Antibiotics come in tablet form, as liquids and incorporated into foods. Some will be easier to use based on the amount of water you are treating. Read the label to make sure it will be easy for you to use.
Many medications will combine an antibiotic, fungal and an anti-parasitic in one formulation. Make sure that all your tank inhabitants can be exposed to these formulations. For example, marine invertebrates cannot tolerate copper and will die quickly if exposed.
If you know a veterinarian in your area that treats fish, a proper diagnosis will help in selecting the best treatment. Likewise, an experienced employee in an aquarium store is likely to know the medications for the most common ailments. If possible, bring the fish and a water sample with you for analysis.