You purchase your tank. You take great care in cycling it. Your hope takes over as you add your first fishs. After three weeks you witness a fish gasping for air at the surface and dying. This is a common occurance among new aquarists. More times than not, it’s not due to poor diet or disease. It’s invisible chemistry.
Freshwater tanks are fragile ecosystems where life hinges on what you can’t see, smell, or taste. Whether the community lives or dies depend on your understanding of your water. That chart represents the “safe” range for each critical value. And remember, numbers on paper is only part of the picture. What does it do in your tank?
Understanding Aquarium Water Chemistry
For instance, let’s use pH. Newbies will attempt to reach a neutral pH of 7.0 by adding chemicals to their water. Wrong! Getting a perfect number isn’t important. Staying in one place are more important. Most tropical species will be better off with a stable pH of 6.5 then a variable pH that ranges from 6.0, 8.0 within a week. Why? Because sudden changes creates osmotic shock. Osmotic shock kills livestock quicker than straight-out toxicity.
It’s not about getting the exact same number as the text book says. It’s about having a predictable environment where the fish doesn’t have to constantly adjust it own internal chemistry just to stay alive.
In a closed environment such as your tank, the nitrogen cycle stops it from being a septic system. As you probably already know, there should of be no ammonia or nitrites in the tank. Period. End of story. No negotiations. Ammonia burns the gills on contact. Even a fish with clear water around him will suffocate. It’s a silent killer. It doesn’t often change how the tank looks until after it has done some serious damage.
Toxic ammonia is converted by beneficial bacteria to nitrite. Nitrite are only slightly less toxic. It too is poisonous. Finally, beneficial bacteria converts nitrite to nitrate. Nitrate is relatively mild and gives you time to address the problem before it kills. Live plants take up nitrate (which they need for fertilizer) and water changes removes nitrate. If you don’t remove it, the entire cycle will back up like a clogged kitchen sink drain.
Besides temperature and pH, hardness gets little attention by hobbyists. Hardness come in two forms: general hardness (GH) and carbonate hardness (KH). They buffer against changes in pH. You know your carbonate hardness is low if you have an unstable pH. When respiration removes carbon dioxide from the water, your pH can crash overnight.
If you’re keeping African cichlid, you’ll want hard, alkaline water to maintain their breeding behavior and shell health. Discus or tetras from blackwater areas of South America thrive in soft, acidic environments rather than hard water. Instead, they does well in soft, acidic water with a lot of tannins. Knowing how to check is only half the battle. Understanding what your fish require is just as vital.
Test Kits come in all price ranges, from simple paper test strips to accurate liquid test kits. Paper strips are handy if you just want to take a peek. However, they’re frequenty incorrect, particularly where trace amounts of ammonia is concerned. Those are the important levels and they’re difficult for paper strips to detect well.
Liquid tests involve more labor. Reagents gets dropped onto vials and compared to a color chart. It’s boring but a little bit of work each week can save your butt in an emergency.
Always dechlorinate new water before adding it to the tank. That chlorine will kill beneficial bacteria living in your filter media, destroying the very system that keeps your fish alive.
Keep your eye on your fish. If they begin to clamp their fins, or gasp at the surface, then there’s obviously something wrong with the water. It is not a sudden mood swing, something is wrong. Stop feeding instantly and check your water. Quick action resolves the underlying issue and turns what could of been a disaster into a near miss.
An aquarium isn’t about controlling nature, it’s about helping natural processes that sustain life. Respecting those unseen forces makes for an automatic system where the tank care for itself. Your patience is rewarded with active swimmer and vibrant colors.
