Aquarium Water Basics

Aquarium water is the most key component of the environment for your fish. Unfortunately, aquarium water is often the most overlooked environmental element.  This aquarium water reference contains articles that will help you provide and maintain the ideal water conditions for your aquarium fish.

If you can’t find the answer to your water question here, please email your question to me and I’ll be happy to respond.

  • 01 of 11
    Ammonia & Nitrite Tests
    Ammonia & Nitrite Tests. John C. Bullas

    Ammonia poisoning is one of the biggest killers of aquarium fish. It occurs most often when a tank is newly set up. However, it can also occur in an established tank when too many new fish have been added at one time when the filter fails due to power or mechanical failure, or if bacterial colonies die off due to the use of medications or sudden change in water conditions. Any time your fish are in distress or you have sudden fish death, consider ammonia as a possible cause.

  • 02 of 11
    Algae on Driftwood
    Algae on Driftwood. Joshua Ganderson

    Algae growth is a fact of life that every aquarium owner will face sooner or later. Some algae growth is normal and healthy, but excess algae growth is unsightly and can be hazardous to fish and plants. Here is what to do about aquarium algae.

  • 03 of 11
    Hagen Master Test Kit
    Hagen Master Test Kit. Tyler Ingram

    Is aquarium water testing really necessary? Some say categorically no, while others test everything and anything. I am a believer in water tests, although what should be tested, and how often, is not a simple answer. Here is what I consider important when it comes to water testing.

  • 04 of 11
    Cloudy Aquarium Water
    Cloudy Aquarium Water. Mike S

    One of the questions I'm most often asked to give advice on is the baffling phenomenon of cloudy water. There is no single answer because there is no single cause. However based on the color and circumstances under which cloudy water appears, it usually can be pinpointed to a couple of basic causes. So don't just take a gunshot approach when trying to solve cloudy water. Get to the root cause, then you'll be able to take the best steps to solve the problem. Here are the basic causes...MORE and cures for cloudy water.

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  • 05 of 11
    Aquarium Rocks
    Aquarium Rocks. Thomas Giuretis

    The impact of rocks on water chemistry is very real, and often difficult to know about before putting the rocks in the tank.  Here are some ways to determine if those rocks you are about to toss in your tank are safe or not.

  • 06 of 11
    Water Bucket
    Water Bucket. PriceGrabber

    The water change killed all my fish! This story is a common but unfortunate one that has some truth behind the urban legend. Take time to read it, because this kind of story perpetuates the myth that water changes are harmful.

  • 07 of 11
    Nitrite Test Kit
    Nitrite Test Kit. PriceGrabber

    Nitrite poisoning follows closely on the heels of ammonia as a major killer of aquarium fish. Just when you think you are home free after losing half your fish to ammonia poisoning, the nitrites rise and put your fish at risk again. Anytime ammonia levels are elevated, elevated nitrites will soon follow, and can quickly be lethal. Here is what to look out for.

  • 08 of 11
    Nitrogen Cycle
    Nitrogen Cycle. Shirlie L Sharpe

    Call it cycling, nitrification, biological cycle, start-up cycle, break-in cycle, or the nitrogen cycle. No matter what name you use, every newly set up aquarium goes through a process of establishing beneficial bacterial colonies. Older aquariums also go through periods during which the bacterial colonies fluctuate. Failure to understand this process is the largest contributing factor to the loss of fish. Learning what it is, and how to deal with critical periods during the nitrogen cycle, will...MORE greatly increase your chances of successful fish keeping

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  • 09 of 11
    Phosphate Test Result
    Phosphate Test Result. Nichole Marti

    Phosphates (PO4) are present in every aquarium, even though many aquarium owners aren't aware of it. If the aquarium is not properly maintained, the phosphate levels will rise and contribute to algae growth. The results are not only unsightly but can become harmful to your fish. Learn what causes phosphates to build up in the first place, and how to deal with them before they reach harmful levels.

  • 10 of 11

    Should you change your water, and if so how often? Water changes are another issue that is often passionately debated. However, it's one that I won't mince words about - water changes are a must. Here's why.

  • 11 of 11
    pH Test Kit
    pH Test Kit. Eric Gillingham

    Water pH is one of those things that make fish owners cringe.  What is it, and why is it important? The answers are here.