What it is, what it does, why it is important...
Most of us use water from our tap to fill our tanks and when we perform our water exchanges. Unknowingly, much of the time, water from our tap is not safe for our fish and other aquatic creatures. To make our water safe, most places in the USA will treat our drinking water in a treatment plant before it is then sent to our homes through our water lines.
Fluoride and chlorine are among the things being added to our water supplies to keep them safe for human consumption. Safe to drink doesn't usually mean safe to put our fish in.
Chlorine forms a bond with ammonia and becomes the harmful chloramine that we hear so much about. With this in mind, chlorine, ammonia, and chloramine are all toxic to most fish, to injured and stressed fish, and can be deadly, especially in a new tank environment where there is lack of established biological filtration in the tank. With the deadly chlorine in the water, adding fish, who's waste content is primarily in the form of ammonia, the chloramine bond is formed quickly during cycling or in overstocked, overfed, and in underfiltered tanks, where excess ammonia is present.
Heavy metals are also often present in our water supplies, regardless of where the water is coming from. Some metals are also toxic to some fish species, and can quickly cause harm if present in our aquarium water. This is more often found in the marine (salt & brackish water) environments.
Our ocean waters differ extensively from our fresh water lakes and streams, as do the fish and their immune systems. Many marine animals are still collected from the wild and sent to our stores, where we purchase them for our home aquaria. These animals are "wild animals" and need much more specific care, leaving much more specific conditions for us to create for their health. The presence of some metals can prove fatal quickly to our marine friends.
Now that we have defined the various problems of using tap water for our aquariums, what should we do about it?
Water conditioner is becoming a much demanded product in fish care, but there are so many to choose from. How do we know which one is "the right one"? Most are still being produced to work alongside of another product, meaning that to properly condition your tank, 2 products must work together. This means expense, this means more storage space, another bottle to sort through when doing regular maintenance. Most of these products take a bit of time to activate and become effective in removing the chlorine, breaking the chloramine bond, and neutralizing any heavy metals that may be present.
The purpose of the 2nd product that most water conditioners are paired with is to add a slime coating to the body of the fish during times of stress and/or injury. Fish produce a slime coating naturally to fend off disease and other illnesses, to aid in healing, and to keep them well protected from their water conditions which may fluctuate. During periods of stress and during handling, this slime coating is often shed and/or damaged, leaving the fish extremely vulnerable while trying to acclimate to a new environment. When dealing with semi aggressive fish or fish known to be "nippy" in nature, damage to fins and body can be regular if they outgrow their tanks, are crowded, or lack enough cover/territory in their tank.
One popular example of such a pair of products is Stress Zyme and Stress Coat. These are # 2 on my list of water conditioning products that I recommend to my customers.
I am not big on promoting specific products on my private website, but here I make an exception. Due to my position at the pet store, I was able to sit in on a clinical trial of the top products on our shelves. I was able to watch as the top 5 products (water conditioners) went up against a newer product on the market, and to say I was impressed would be an understatement. Tetra has successfully designed one product that does the job of 2 in any other product line of the same type. AQUASAFE is the #1 on my list of water conditioners today! I use it at home, and it has become the only water conditioner we use at the store. Not only was this product more economic to our customers, but we were able to witness how much quicker it was in activation. While most of the products tested took 5 - 15 minutes to activate, AQUASAFE was immediate.
MY COMPLIMENTS TO TETRA FOR GIVING THIS PRODUCT TO US!
Important note: When using water conditioner, it is important to keep in mind that too much of a good thing can also be no good. Please remember to only treat for the amount of water you are changing and don't use this or any water conditioner product to attempt to eliminate waste, as it is not designed for this purpose. Over using water conditioning products can produce dangerous effects in your water quality over a prolonged period of time.