Obtaining Medications

As anyone who has visited an aquarium store knows, there is no shortage of commercial medications available for treating fish disease. However, medications sold and used in the aquarium hobby vary in quality and effectiveness. In fact, some fish medications simply do not work. In 1974, Trust and Chipman tested eight products marketed for the treatment of bacterial diseases in aquarium fishes. The products contained erythromycin, neomycin, nitrofuran, penicillin, sodium sulfathiazole, sodium sulfamerazine, sodium sulfamethazine, streptomycin or tetracycline. When used at the concentration recommended by the manufacturer, the products failed to inhibit the growth of bacterial species known to be potential pathogens of aquarium fishes. Furthermore, one of the more effective antibacterial formulations was toxic to the fish. The results also showed that markedly higher levels of the formulations also failed to significantly decrease the numbers of viable bacteria in the aquarium water.

Medications for the aquarium can be found as dry ingredients (crystals or powders), or in liquid form (solutions). Sometimes, the chemical comes in pre-packaged amounts. One should follow the manufacturer's instructions for treatment, as different manufacturers use different chemicals and concentrations of the active ingredients. It is advisable to use only those fish medications that list the active ingredients on the label so that you know what you are using.

Many popular fish medications sold in pet stores will simply not work when used as directed. The delivered dose of active chemical is often below that recommended in the scientific literature - many don’t even state the active ingredients. However, it is NOT a safe practice simply to increase the dose rate, and in fact, such measures can have disastrous results. In addition to this, many aquarium chemicals can cause problems with established biological filtration. It is worth noting that control of disease in aquariums may further be complicated by the presence of filtration (biological and chemical), sand, gravel, plants, and organic matter, since these will reduce the efficiency of the chemical compound by direct inactivation. Therefore, you need to be well informed on the subject of aquarium fish medications and should always seek out the most reliable aquarium specialists when attempting to treat a problem unknown to you.

Medications have an expiration date beyond which they may lose their effectiveness. Light, moisture and elevated temperatures are factors that may dramatically accelerate this rate of degradation. Unfortunately, many remedies available in pet stores do not carry any expiration date, nor are kept under acceptable storage conditions. Warm temperatures, moist environment, or stored on shelving under bright lights are factors that will affect commercial preparations sold in the hobby. Other times it is the hobbyist who decides to use old products! These situations should be avoided.

Unless you have a very large number of aquaria, do not buy medications “just in case”. Few treatable conditions require an immediate use of medications, and in most cases it is better to start with water changes or just careful observation; then buy a fresh package of the exact medication that you need. Here are some useful tips to consider on the subject of purchasing and keeping medications:

Buy medications from a shop that has a high volume of sales and stores them under acceptable conditions. • Stay away from dusty or moisture-stained packages. • Sealed containers are preferable to boxes or bottles that can be easily opened and contaminated. • Formulations with an expiration date and a clear label explaining contents and concentrations are much more reliable than those with unknown or poorly described content. • Store medications in a cool and dry place. • If you opened an airtight container, it is unlikely that after a few months the content will still be viable, and you should dispose of it in a safe place. • Keep you aquarium medications out of the reach of other pets or children.