While most hobbyists are blessed with reasonably good tap water to use to fill their aquariums, there are some water conditioners that will be required to make the water safe for the fish or needed to adjust the water to more closely match natural conditions. Unless the hobbyist has well water, the tap water will contain either chlorine or chloramines to kill bacteria in the water lines. While this is good for humans, either chemical can be deadly to fish and invertebrates in the aquarium. Chlorine is fairly simple to neutralize with any of the myriad of chlorine removers on the market. Chloramines are a bit more of a challenge, since it takes two steps to neutralize this chemical. The first step is to neutralize the chlorine, but this leaves the very toxic ammonia in the water. Chloramine neutralizers will have a second agent to chemically bind to the ammonia to make it safe. For this reason, it is important for the hobbyist to know what chemical agent is used in the local tap water. You can use tap water conditioners like AmQuel, Prime, Complete Water Conditioner or Ammo Lock II to eliminate chloramines in the water.
If the hobbyist wishes to adjust the pH of the water, understanding the General Hardness (GH) and Carbonate Hardness (KH) will be important. Marine aquariums are rather easy to keep at the proper pH range (8.0-8.4) with just the salt mix itself. If the fish load is too high, or not enough partial water changes are made, the pH in the aquarium may start to drop below 8.0. If this occurs, using marine supplement buffers like Marine Buffer, Reef Buffer or Super Buffer dKH will help lock in the correct pH range. If the drop in the pH is caused by a lack of the proper alkalinity, this is usually associated with low calcium levels. The addition of calcium supplements or KH builders can usually stabilize the pH value. Freshwater aquariums with soft water can be easily maintained at the desired pH level with the use of water conditioner buffer products like Proper pH, Neutral Regulator, Acid Buffer/Alkaline Buffer, African Cichlid Buffer or other similar products. If the aquarium water is hard, changes in the pH will be difficult to impossible without the use of a reverse osmosis unit or DI unit.
The neutralization of ammonia was discussed in treating tap water, but it can also be found in the aquarium as a result of the natural metabolism of the fish. If the nitrifying bacteria of the biological filtration system are not capable of handling the ammonia wastes, ammonia will slowly build up to toxic levels in the aquarium. The use of the ammonia neutralizing agents can also be used at this time to protect the fish from the ammonia. Ammo-Carb and White Diamond are a few products made from Zeolite, a natural material that removes ammonia from water. These products can be placed in the filter system to continuously remove ammonia until they become exhausted and need replacement. This is most likely to occur in a newly set-up aquarium or in one where an antibiotic treatment has damaged the beneficial nitrifying bacteria. If you use water conditioners like AmQuel or Ammo Lock II to neutralize the ammonia, please be aware that most test kits will still register the presence of ammonia in the aquarium, but that the agents have chemically neutralized its toxicity.
While not toxic to the fish, phosphate in the aquarium can lead to excessive algae growth. The use of phosphate removal media like Phos Zorb, PhosGuard, PhosBan, Phosphate Sponge or Phosphate Filters can be used to remove any/all phosphate in the water. Phosphate is one of the waste products of food metabolism, so the level in the aquarium continuously increases. Phosphate is also found in tap water of some cities and can be removed with DI units or pre-treating the water with one of the above agents.
Usually, the best method to control nitrate levels in the water is to perform regular partial water changes. There are a few water treatments that will aid in removing nitrate, but these require proper set-up to work correctly. Many of these products do not actually remove nitrate themselves, but serve as a media/surface area for the bacteria that use nitrate as their oxygen source. To work properly, the denitrification media should be placed in a container where there is a very slow flow of the aquarium water through the media, the slower the better. In a marine aquarium, this media can possibly eliminate all of the nitrate, but the heavier fish load of a freshwater aquarium will usually require frequent partial water changes to control nitrate levels.
Activated carbon is perhaps the most common of the water conditioners, good at removing acidic wastes, organic wastes and discoloring agents (dyes from foods) found in aquariums. Other treatments include manmade resins designed to specifically remove wastes/chemicals in the water. BioChem Zorb, Purigen, Opti-Carb and Chemi-Pure are some of the most popular of the “general” resin water conditioners. CupriSorb is an example of a resin made to remove just one type of chemical (copper) from the water. The Poly Filter is an example of a fiber pad impregnated with chemical bonding agents to help purify the aquarium water. One advantage to some of the resin treatments is their ability to change color to let the hobbyist know when they are exhausted, and many can then be recharged and reused!
One of the newer classes of water treatments in the aquarium hobby is the introduction of probiotic treatments like Immune Plus or Marine Max. These products add thousands of beneficial microorganisms to the aquarium to more closely approximate the natural conditions. These microorganisms compete with harmful (pathogenic) microorganisms and also help trigger a better immune response in the fish, sort of like a vaccination for fish. These products have been used for years in the aquaculture industry, but have just recently become available to aquarium hobbyists. Along with the new high-efficiency biological filtration systems, these probiotic compounds can greatly enhance the quality of life for the fish.
Vitamin and trace element solutions can also be added to the aquarium water to help enhance the health of the fish and plants. Products like Vita Chem, Zoe Vitamins or Trace Elements are examples of some of the readily available conditioners for the aquarium. Most of the vitamin compounds can be added directly to the aquarium water or soaked into the food before it is fed to the fish. These vitamins can make up for any lost during the manufacture of the prepared foods. This can especially be important when conditioning fish before breeding them, and in raising the fry.
One last class of water conditioners to be discussed in this article is the clarifiers. These products help re
move floating debris, algae and sometimes bacteria found in the aquarium. Most work by causing the minute particles to clump/stick together until they become large enough to be trapped in the mechanical filter or else sink to the substrate. Examples of this type of product include Accu-Clear, Bright N’ Clear, Clear Water, and Tropical Clear. This last product also includes cultures of “sludge” eating bacteria to help control waste build up in the substrate. Aquarium Pharmaceuticals has an algaecide called AlgaeFix that can control the algae but does not bother the rest of the plants. This will certainly be a boon to the freshwater planted aquarium keeper!
This discussion has presented an overview of many of the different types of water conditioners available for the aquarium hobbyists. Most are designed to work in the aquarium, but a few can also be used to pre-treat the tap water to make it safe for the fish.