Water is the support system for all aquatic life. It provides the medium for movement, oxygen, toxin disposal and every other aspect of a fish's life requirements. As such it is the single most important element in the aquarium to keep fish healthy and disease free. Its chemistry can be extremely complex if you want to make it so, but for the novice aquarist there are some simple concepts that must be understood. Water is the single most important factor in the success during maturation of the beginning aquarium.
Since water is so important, it is pretty surprising how often it is neglected by the modern fish keeper. This often translates into serious omissions when advanced hobbyists discuss the new aquarium with beginners. Sometimes the all-pervasive aspect is just simply taken for granted. Local pet stores can provide quite a wealth of information on your regional characteristics. The most important of these characteristics are pH and hardness. Although in some cases these are overstressed, they do form an important aspect of successful fishkeeping for many species. Other important factors, that are normally discovered by testing are the fluctuations of various compounds, such as nitrate and phosphate coming from the tap. These characteristics need to be handled as a separate topic.
The most vital characteristic of many municipal water supplies is the type of chemical added by the municipality to make the water "potable" or fit for human consumption. Cities and towns often add chlorine or chloramine to their water supplies to ensure the safety of the drinking water for their citizens. Either chemical is effective in destroying most disease causing bacteria that could be carried in the drinking water. Unfortunately, both are also quite effective in killing the beneficial bacteria that help a new aquarium installation as well. This indiscriminate destruction of bacterial strains is absolutely required to ensure the drinking water supplied to the tap is safe and harmless when it is consumed by humans, but must be addressed when making water safe for fish.
The problem is that chlorine and chloramine are also deadly to fish. These must be removed BEFORE the water may be used to keep fish alive. There are any number of products on the market that will do the job, some much better than others. Local advice is strongly recommended in this area.
Well water may not have the toxicity added to the water by a city, but it can have other problems associated with it, most often in the form of extreme hardness or heavy metal toxicity. Often this water is softened by commercial water softeners that use salt for their softening effect. This is also a cause for concern, as the softening process can leave the water unsuitable for fish.
Making water safe for fish
Well Water
Well water provides a number of challenges to the modern aquarist. The solutions are varied. It is best to seek the advice of a local pet store expert who should have a better idea of the particular problems local well water may pose in the region. If well water is causing stress or even death for your fish, it it might be time to consider using distilled water or a commercial water treatment system to remove everything from the water. The result is as close to pure H2O as possible. a common, albeit expensive method to treat unsuitable water is to use reverse osmosis. This is almost required for success when dealing with a marine reef or other delicate salt water species, but definitrely overkill for the new hobbyist tank. One problem with distilled or RO (Reverse Osmosis) water is that the pH may require chemical adjustment, it is also as close to pure H2O as possible. Standard tap water is far from pure, it contains many other trace elements that are vital to fish, so the use of 100% distilled water all the time is highly discouraged.
If you must use distilled or RO water, use it occasionally, and mix it with town water if possible. I have known many avid hobbyists who live on farms or have well water that drive to neighbors to fill bottle after bottle of town water. This will help provide many of the elements that fish need to keep their osmotic pressures in line and proivde the right buffering for stable conditions to be maintained.
Municipal Tap Water
Most aquarists have municipally treated water delivered to the home or office. Although the assorted water characteristics vary tremendously by region, a few "rules of thumb" have provided me with success for the past few decades.
Pond Rule of Thumb # 1
NEVER add untreated tap water to an operating aquarium. Always ensure all chlorine or chloramine has been neutralized before it can contact any live fish. Follow the instructions on your chosen water conditioner carefully. Remember most preparations are labelled for US gallons. It is better to overdose than underdose
** Be sure you know the capacity of the aquarium (in US gallons) when it is empty, in the long run this is the best quantity to use when medicating the aquarium. **
Chlorine Removal
Chlorine is essentially a gas - it enters the water and will remain there for a limited length of time. After this it disperses into the atmosphere, leaving behind sterile water that is suitable for supporting life. The old time aquarists knew this and always kept uncovered containers full of tap water to age in case of emergency and for regular aquarium maintenance. Unless heated, this method had the potential of causing rapid temperature fluctuations when it was added to a tropical community.
Modern methods are quicker - use a suitable water conditioner and the prepared tap water is ready for immediate use. Run the water for a few seconds to a minute and adjust the temperature to close to the aquarium before adding the dechlorinator/water conditioner. Running the water for that intial period will flush out any heavy metal ions, such as copper, that may have been added while the water was standing in copper plumbing. Plastic pipes do not offer this problem.
A common mistake made by many novices is to add the water conditioner to the aquarium directly, and simply pour water in straight from the tap. When this happens, there is a segment of time when the chlorine is active within the aquarium to stress and kill fish. Chlorine (and Chloramine) is an oxidizer, it will burn anything that it contacts, such as delicate gill tissue. The only time I would suggest that untreated tap water might be added directly to an aquarium would be when the initial fill is occurring. There are no fish in the system at this point and as long as the adequate dose of water conditioner is added prior to the fish, there is no harm done. BUT, in every other case, new water should be treated before it enters the living space of an established aquarium.
I can't stress the importance of regular aquarium maintenance enough. Always prepare your water in a clean container, removing chlorine completely in the bucket BEFORE adding the replacement water to the aquarium. It is highly recommended to purchase a plastic bucket expressly for aquarium water ONLY. Label the bucket:
"FOR AQUARIUM USE ONLY"
and never, Never, NEVER use the bucket to hold a cleaning solution with soap!!!
Soap is toxic to fish and it remains in the plastic pores to cause stress to aquarium inhabitants - since embedded detergent and soap traces are released into treated water during later water changes. If a bucket has ever been used with soap or detergents, it should never be used to transport aquarium water to a tank.
Consider one of the many water conditioners on the market, Aqua-Plus (Nutrafin), AquaSafe (Tetra) and Stress Coat (Aquarium Pharmaceuticals), all protect by artificially coating the fish with a replacement compound when/if the natural slime coating has accidentally be removed by netting or other stressful situations. Slime is a fish's natural defense against external parasites. When this protective layer is scraped away, pathogenic organisms have an easy time invading under the scales and gaining a foothold. Water conditioners are especially recommended for a newly set-up aquarium where fish are added immediately. Since they must be netted and moved, a water conditioner with this feature will add a complete protective layer just when the fish need it most, during the most stressful time of their lives.
Chloramine Removal
Chloramine is deadly.
It is added to the water supply of some cities where the water is transported for long distances or stored for an extended period. Two I know of personally are Edmonton, Alberta (for as long as I have known the city) and Ottawa, Ontario (for the past few years). Chloramine is used because it stays around for a long time. It doesn't dissipate like chlorine. It MUST be chemically removed. Since it is a combination of chlorine and ammonia in liquid form, it must be removed in two stages.
Stage 1) The Chlorine bond must be broken. Almost any pure Chlorine remover can be used. There are a number of quality chlorine removers on the market that will break the chloramine bond adequately - Chlor-X and SuperChlor jump to mind. Read the directions for chloramine removal very carefully and ensure the dose is high enough to work effectively. But, in the long run, I highly suggest using the previously mentioned water conditioners like Aqua-Plus with their added slime bandage and heavy metal neutralizers as well.
The only caveat for any of these products is that standard chlorine doses are not powerful enough. Normally a three to four time dosage is needed to release the chlorine and precipitate it out. Always be sure to use an adequate dose to eliminate the chloramine from the water supply, if in doubt, use slightly more than the instructions require. In this case, truly it is better to be safe than sorry.
Stage 2) When the Chlorine-Ammonia bond is broken, the ammonia that was combined with chlorine is released. This toxin can kill fish in relatively low concentrations when the pH of the water is high. If the water is acid, this problem is greatly diminished, but must be factored in nonetheless.
There are a number of ways to eliminate the released ammonia in the tap water after the chlorine has been eliminated. I generally let nature take its course, relying on the natural ability of the nitrogen cycle to remove ammonia from the water column. Cycle (Nutrafin) is always added regularly to my aquariums to ensure the maximum efficiency of the biological filtration, no matter what filtration system I am using. I have found its extremely high concentrations of beneficial bacteria (nitrosomonas and nitrobacter) reliably inoculate the aquarium. Proper use of Cycle right from the beginning does help keep fish much more stable and less vulnerable in the initial six weeks or so of bacterial filter maturation. Over the years, I have found that by dosing the tank regularly, the possibility and outbreaks of disease is lessened. The places available for pathogenic bacteria to gain a foothold are out competed by the powerful populations of beneficial bacteria added every week. With this powerful advantage, small increases in ammonia from added tap water are consumed without noticeable stress to the fish. In larger aquariums, over 40 gallons, the water capacity is often great enough to disperse them minimal amounts of ammonia released from breaking the chloramine bond that the total amount of ammonia is not very deadly.
In established large aquaria, I generally ignore the added ammonia since a properly functioning bacterial filter will utilize it before it can become a stressful condition for the assorted inhabitants. A powerful biological filter bed also removes any ammonia that may be released by treated tap water in even a smaller aquarium.
With susceptible species or aquariums where even the slightest increase in ammonia concentrations are lethal, I suggest considering adding a Zeolite filter media in the filter chamber, at least in the beginning. Zeolite products are normally marketed as Ammonia Removers and are available from a number of companies. Zeolite media acts like a resin to chemically bond with the free ammonia and remove it from the water solution. Ammonia Remover preparations can be recharged, they simply have to be placed in a strong brine solution to force the captured ammonia from the substance. I do not highly recommend this practice since there is no physical change that identifies how charged the ammonia remover is, or how long it will continue to remove passing ammonia. The recharge is not always very efficient and I tend to consider it only when beginning the system. Once the beneficial bacteria are available, I rely on the biological filter and regular additions of Cycle to maintain the level at 0.0.
Since ammonia is released by a solution of brine water, it follows that Zeolite preparations are not at their best in marine situations. What aquarist would knowingly put a material into his aquarium that will tend to release the very poison that they are trying to eliminate? For this reason, I personally do not recommend the above mentioned Zeolite filter materials to ever be considered for marine aquarists, they are strictly for fresh water, and the packages do normally state this restriction.
Water is one of the most important factors determining the health and well being of the inhabitants of the new aquarium. It is often overlooked, but it is truly the universal solvent, over time it will dissolve an amazing amount of other compounds and some of those will readily enter into the solution. It is one of the main reasons that you must never do a complete water change, in a new or older, mature aquarium. The characteristics of the water that has been in the aquarium for a while are surprisingly different from fresh water from the tap - the fish have adjusted gradually to these differences and new tap water can be a major shock to the system. I do suggest that any water change, unless there is a major incident happening in the tank, should never be more than 20% of the aquarium's capacity. In general, being a rather lazy aquarist, I will do this once every two weeks, but if required, this can be stepped up to every week. Changing much more will simply add more stress to the fish who are adjusting to the maturing ecosystem. The entire system depends on the water, hopefully now you understand this vital medium at least a bit better.
