Health & Care

Some novice hobbyists are uncertain of the key features of goldfish. As a starting point, goldfish should have two eyes, two ventral fins, two pectoral fins, and two anal fins. Its dorsal should be erect, or where the goldfish has no dorsal, its back should be smooth. The goldfish should be well conditioned and well proportioned. If it is a scaled type, as most are, it should have good scale development that is evenly distributed, and not patchy. After confirming the attributes are in order, one will turn their attention to the color and deportment of the fish.

Given consistent and proper care, goldfish should live at least 10 years, and some varieties will live 20 to 30 years. The oldest known goldfish was 42 years old.  Experience teaches that for a fish to live long and be healthy, it is best to adhere to a few fundamental principles. Over time, the enthusiast’s knowledge becomes more sophisticated, but for beginners, here are the cornerstone rules:

Tank Size

A simple rule of thumb will help you to determine the size of the aquarium to be purchased: for every inch of fish (from the nose to the tip of the tail), you will need at the very least, 2 gallons of water. For example, a 20-gallon tank will house 5 two-inch goldfish. However, over time fish will grow and so calculate conservatively. Do not ever overcrowd the tank. Remember, less is better; too many create problems.

Water Quality

Fish require a clean environment in which to live. It is imperative that a weekly water-change regime be established by removing 10-20% of the water from the aquarium. Fresh water, which has sat for at least 24 hours after coming from the pipe to allow any chorine content to evaporate, should then be added. The filter should be maintained on a regular basis. When rinsing the filter, do so in a bucket containing the water removed from the aquarium, so as not to lose the bacteria that has built up and which is essential to establishing a more natural environment for the fish.

PH Level – Potential Hydrogen

This is one of the most stealthy and deadly forces working against the good health of the fish. The Ph level of an aquarium system must be about 7.4. If ever it falls below, one should immediately buffer it to a level about 7.4, but keeping it within the range to 8.


Observing fish during an animated feeding is a delight for the fish hobbyist. The downside is that fish waste routinely enters the aquarium causing the ” ammonia” index to rise sharply. This poses a significant hazard to the well being of the fish if not addressed regularly. Fish excrete ammonia through their gills and in their waste. Nature’s cure for this water “toxin” exists in two forms of beneficial bacteria, which serve to neutralize. This neutralizing process is known as the “nitrogen cycle”. When coupled with the good bacteria, nitrosomonas, the ammonia is converted into the compound, nitrite. This then can be broken down into nitrate by the addition of the good bacteria, nitrobacter. Nitrate is an environmentally friendly compound, which may be absorbed by the plant life as a fertilizer. To see the nitrogen cycle through to this end is a desirable and achievable goal.


When you first set up your tank, or when you are carrying out your weekly water change, or at any sign of trouble, salt is the best and quickest home remedy. Salt is effective in eliminating some 80% of parasites including: ichthyophthirius, costia, trichodina, epistylus, glossatella and chilodenella. Add 1 tablespoon of salt to every gallon of water in your tank. This should render your salt solution level at approximately .3%, which is the ideal balance to rid parasites. Ensure that your water is simultaneously well aerated.


Most goldfish and koi have immigrated from a warmer climate than Ontario, and therefore enjoy warmer water temperatures. Ensure that your aquarium’s water temperature are kept between 72 and 78 degrees Fahrenheit.

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