The Ultimate Guide to Buying Water Treatments for Your Aquarium

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The Ultimate Guide to Buying Water Treatments for Your Aquarium

The most important part of an aquarium is the water that the fish will live in. It is the environment that will keep them healthy and breathing properly, or make them sick and possibly threaten their life if the correct measures are not taken to maintain the tank environment. So it is vitally important to keep the water as clean as possible. This can be helped by ensuring that the water in the tank is changed regularly, and that only enough food is given at each feeding so there are no leftover particles to pollute the aquarium.

There are a myriad of treatments for problems which can affect the water in an aquarium, all of which are available to buy on eBay. These treatments can help to maintain an environment that is already in good condition or to modify or treat a problem with the water in the aquarium.

Tap Water

Adding water to an aquarium straight from the tap with no treatment can harm or even kill the inhabitants. This is because most water from a utility supplier has added chemicals to ensure that is safe for humans to drink.

In order to comply with regulations and standards, local water companies usually add chemicals such as ammonia or chlorine to water supply, which keep the water safe for human consumption. These added chemicals are however, harmful to fish and do not make a suitable environment for them to live. For example, chlorine is used to kill bacteria in the public water supply; this is fine in small amounts for animals and humans but toxic to fish, as the chemical causes damage to the gills of fish even in low concentrations.

Chlorine is an active chemical and it will separate into the atmosphere over time. This has led to water companies using ammonia in the water supply to strengthen its ability to keep bacteria in check. This also converts some of the chlorine into chloramines, which do not dissipate as quickly.


It is important to remove the chlorine and chloramines from the water before exposing any fish to it. This can be done by using a neutralising agent that will bind with the chlorine, or by manually aerating the water to encourage the chlorine to dissipate.

A dechlorinator treatment can work only with chlorine or with chlorine and chloramines. A product that does both is a good idea because many water companies rotate the use of ammonia and it is almost impossible to know if the water contains chlorine, chloramines or both.

Ammonia can also be treated with a neutraliser treatment. The biological filter will eventually remove the ammonia, but it takes a long time and the damage to the fish would already have happened. However, eBay has many different treatment products to solve this problem.

A non-chemical solution for chlorine is to circulate the water in separate container for a minimum of a day. The rapid circulation helps the chlorine to dissipate and lets other dissolved gasses dissipate. But this will not significantly affect chloramines and ammonia.

pH adjusters

The local water company may use chemicals to adjust the pH of the drinking water so that it is less corrosive to the metal pipes used in most people’s houses. pH adjusters will allow adjustment of the pH with the addition of acids and bases, and there are many varieties available on eBay

There are some situations where it is difficult to adjust the pH level. If the buffering level of the aquarium environment is high, then adding an acid may result in a temporary change that bounces back quickly. Another problem can be the amount of dissolved solids in the water. The addition of chemicals will increase the amount of dissolved solids making the environment for the fish far from ideal.

Fish will generally prefer a stable environment that has a stable but not ideal pH. A pH that is constantly changing can stress fish so it should be avoided, if possible.

Well Water

Well water can be much better than the water supplied by a water company. It generally does not have ammonia or chlorine added and should not need to be dechlorinated. Deep well water is naturally filtered and can be very clean and pure. The natural filtering process may mean that there are a higher proportion of minerals than other sources of water.

While well water is generally, less polluted than many other water sources there are some things to be aware of to keep the fish at their best.


Well water may have higher levels of nitrates, which can be a particular problem as water changes are the way that nitrate levels are lowered. This can be a bigger problem in agricultural areas where run-off from fertilisers can increase the ground water levels of nitrates. There are chemicals that can lower nitrate levels as well as filter kit add-ons. The addition of plants also lowers nitrate levels as plants use nitrates to grow. Online stores such as those found on eBay have many specialist products and information on this particular problem.

Dissolved gasses

Another problem with well water can be dissolved gasses. This can cause changes in the pH level as gases such as carbon dioxide come out of the water. This can be detrimental to fish and should be avoided, if possible. A simple way to ensure that dissolved gasses are removed from the water is to aerate the water for several hours. This quick and easy solution will also allow the cold well water to reach a warmer temperature, which the fish will appreciate.


Fish medicines are important, but dangerous if used improperly. It is difficult to diagnose many fish diseases unless a veterinarian that is experienced with fish sees a scraping or gill biopsy.


There is a move to restrict available medications because some have been misused. This misuse can risk the fish that they are given to and cause drug resistance to develop. It is important to only give medication when a disease has been confirmed and to use the full course to ensure that there is no relapse.

White Spot

This is a common freshwater fish problem also known as ‘ich’ (Ichthyophthirius multifiliis) that has a distinctive white spot pattern on the fish affected. It is a parasite but many people try to treat it with antibiotics, which will have no effect. The treatment for white spot will also not have any effect on other fish diseases. As with humans, many medications have side effects which may stress or lower the immune system of the fish. If the fish is fighting a disease and suffering side effects from an incorrectly supplied medicine it is much more likely to have a negative outcome.

Marine Supplements

Marine Supplements are minerals which can be added to a tank environment to optimise water quality and benefit the inhabitants. Some common ones that can be purchased on eBay are:


If the water will fill a reef aquarium, calcium is normally a supplement that you may need to add, as the water in the aquarium will have a certain amount of calcium to sustain the coral. In a natural reef situation, there are currents and waves constantly moving higher calcium water into the reef and removing the depleted water.

You could continually add new water but usually a calcium supplement is added when a test kit shows the level is low. The kit and supplements can be found on eBay.

Trace supplements

There are many products that provide trace elements for aquariums that are particularly useful in reef aquariums. Being a closed system, the aquarium can be quickly depleted of the available trace elements. There are individual supplements such as carbonate, strontium, iron and iodine or general supplements that have a formulation of all the required elements.

It is important that any supplementation be considered and part of a structured program to keep a balanced environment in the aquarium.


Aquariums can be basic or complex environments that contain varying levels of aquatic animals, fish and plants. In an effort to get an aquarium environment as close to the natural environment it is mimicking, there are hundreds of tonics, conditioners, and supplements available to tweak each area.

Plant tonics and supplements

The plants in an aquarium can be difficult to balance against the needs of the fish and the need to keep nitrates relatively low to avoid algal blooms. Specific supplements to do this are popular but need to be careful, controlled to avoid problems.

Black water tonics

Fresh water stream aquariums can benefit from black water tonics, which are formulated to increase the acidity and to soften the water by using humic acid and organic compounds. This gives a better environment to keep fish that are found in rainforest streams. This and many other tonics can be found on eBay.

How to Buy Water Treatments on eBay

Water treatments for an aquarium can be found on eBay under the Fish section in Pet Supplies. It is possible to browse the selection available here in order to compare prices and view available produces. If looking for a specific product, use the search function by typing the name or a feature of the produce into the search bar, and then narrow down results using the options in the left bar menu.


There are many treatments and they all aim to do specific things to the aquariums environment. It is important to follow the instructions and know what the local water quality is like. In most cases water has a wide spread of minerals that are sufficient for a normal aquarium between water changes. There are also products such as electrolytes that are promoted as attacking ‘free radicals’ and keeping the fish in the aquarium in better health.

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