Water Chemistry Basics
Water Chemistry Basics
Marc Grover (Professional Aquarist) gives expert video advice on: Why are temperature and water chemistry important for my aquarium?; What pH levels are normal for my aquarium?; How do I create the right level of oxygen in my aquarium? and more...
Why are temperature and water chemistry important for my aquarium?
Temperature and water chemistry are probably the two most important parameters that you have to control for your fish. You have to look at your aquarium as not only a place for your pets but as it's own ecosystem that you have to control. It's an environment for these animals. Unlike your cat or your dog in your world, they have to have their world, and their world is so small compared to a lake or an ocean or a big river. You have to control the waste levels, the temperature, and all the different chemistry parameters to give your fish the best chance of being healthy and staying alive for a long period of time.
What is a 'nitrogen cycle' in an aquarium?
When people mention the cycle, it's the nitrogen cycle. And what happens when you set up an aquarium, it is a sterile environment, and as soon as you put a fish in it, the fish is going to invariably go the bathroom, and you're going to feed the fish. And all of those waste products are going to break down and dilute. When they do that, they are going to become quite toxic to the fish. When you go through a nitrogen cycle, you start with ammonia, and as that builds up, a bacteria grows that converts that ammonia into nitrite. Both of those two components are very toxic to fish. After nitrite develops and raises to a high level, a second bacteria comes in and converts nitrite into nitrate. It, too, is toxic, but fish can tolerate such high levels of it, typically speaking, that we really don't look at it as a toxin so much. All of those things are acidic in nature, and most fish don't like acidic water. There are exceptions. They like neutral and very alkaline water. So those are always working against you, eroding away the other key factor of the cycle, your pH. So when people talk about a nitrogen cycle, they put their fish in the tank, perfectly sterile environment. They go through ammonia, nitrite, nitrate, and then they come out on the other side, back to, not a sterile environment, but a more stable environment.
Why do I need to check the water pH of my aquarium?
PH is critical, namely stable pH is critical. All of the ammonia, nitrites, and nitrates are all acidic-based toxins and they're constantly try to drive your pH down. Natural tap water is anywhere from neutral 70 on up to about 78 in most areas. Fish adapt to that pH. If you've got acids and waste constantly trying to drive that down, that's really going to irritate your fish. PH is log rhythmic so to move from 70 to 69 is 10 times basically, over simplified 10 times more shocking that you could seem to be because of the value of pH. It's critical on aquarium, testing is very simple and you get a test kit at any fish store.
What pH levels are normal for my aquarium?
Typically fresh water is neutral or slightly alkaline. Soft water with all the different alkaline components, be it calcium and minor or major traces, is a lot more alkaline. Fresh water typically is between 7.0 and 7.8 and saltwater between 8.1 and 8.3.
Why do I need to check the water 'alkalinity' or 'hardness' in my aquarium?
Alkalinity or water hardness which are sometimes the same thing, for this discussion we'll call it the same thing, are really important to keeping pH stable. They are basically measuring the amount of mineral content or trace elements that are in the water. Those trace elements act as a buffer of your pH again, fighting the bad guys which is acidic amonia nitrate, nitrite and some other things like phosphate that we haven't talked about, kind of fighting them from driving your pH down. They're the stabilizers of the pH, which is critical to any type of system be it fresh water or salt water. When you're testing for alkalinity, KH or DKH, alkalinity or water hardness there are simple kits like there are for almost anything you're going to test for that you can get in any reputable aquarium store. They're very simple and easy to read. They will tell you basically what you're levels are and what you want them to be. It's not nearly as critical typically in fresh water as in salt water and again when you're talking the salt water fish only versus saltwater invert coral and fish they have different requirements as well, so you have to kind of know specifically what you're testing for based on what you have. But they are very easy to use, the test kits are very easy to use and they are very easy to read.
Why do I need to check the 'salinity level' or 'gravity' of water of my saltwater aquarium?
When you're dealing with the specific gravity of a saltwater aquarium, keep in mind that saltwater fish almost exclusively come out of the ocean. The ocean runs a specific gravity of 1.023 to 1.024 almost in every tropical sea on the planet. That's what the fish are used to. If you change that dramatically, its like pH, they just have very little time to adapt to it. Changes in the ocean happen very slowly and if a fish doesn't like a particular area for whatever reason it can leave. It can't do that in your aquarium, it is totally stuck with whatever chemistry and ecosystem you create. Therefore, it's paramount that you get the specific gravity where you want it to be, 1.020, 1.021, 1.022, somewhere in that range and then you keep it there as consistently as you can. There are tricks and ways to manipulate that for parasite control and other things, but for our discussion and all intents and purposes you really want to keep it at a certain level, and you want to control it as much as you possibly can.
What is an 'air stone'?
An air stone is a little, porous, literally like a little stone that attaches to air line tubing, which is then attached to an air pump. A vibrating pump will force a lot of air through that air tubing, and then through the air stone and you'll get anywhere from fine to coarse bubbles that will come out of that air stone and again, oxygenate the water mostly as they break on the surface