In Fish Keeping, part 1 I gave an introduction to the hobby of owning aquariums and keeping fish. Part 2 discusses the primary hardware required to get started.
Let’s start off talking about water. More than likely the water you will be using will be coming right from your tap. This water usually comes from a municipal supply, so is considered safe to drink. This should be fine for most common aquarium fish. For those on a well, we may need to make some considerations (below).
If you have municipal water, try to get the annual water quality report. They are required to test the water annually and make the information available to the public. Note the source of the water. Is it from surface water, such as a stream, river, or lake? It is from underground aquifers via wells? Also note any unusually high levels of various minerals and metals. This information may impact which fish you purchase. (Research your fish!)
Surface water will usually have less dissolved solids and be considered “softer” water. Well water will usually have more dissolved solid and be considered “harder” water. Both of these are on a water “hardness” scale. Wikipedia has an explanation. The natural habitats of fish span all water types. Some prefer soft, some prefer hard. Again, do some research!
USGS has a map to generally show the hardness of the ground water in various parts of the US. If you are visiting from outside the US I’m not sure were to point you, but I do thank you for stopping by. There should be a local, regional, or national office that keeps records of water quality.
It is generally a bad practice to use water than has passed through a water softener. While the water has less dissolved solids, it has picked up some water softener salt in the process. Too much salt in the water can cause issues for your fish. Fish that come from brackish water (where saltwater and freshwater meet) can handle it. Most cannot. But there is a solution for it (below).
In Part 2 I mentioned getting a water test kit. The one I’ve always used is the Freshwater Master Test Kit from API. Use this kit on the water coming from your tap. Measure the hardness of the water, the pH, the nitrites, and the nitrates. You may need to use the high range pH test if your have hard water. This knowledge will help you make decisions on which fish to eventually place in your aquarium. The fish will have a preference for hardness and pH. Nitrites and Nitrates are more of an issue for you, the budding aquarist.
Nitrites and Nitrates are a concern because they are waste products in the Nitrogen Cycle. What happens to fish waste is something you need to know and understand. When you feed your fish, every bit of food that did not get eaten will rot in the aquarium. This will produce ammonia in the water. The fish will process the food and will release the waste into the tank. This adds more ammonia. Fish constantly urinate in the water, urine breaks down into, you guessed it, ammonia. Ammonia is toxic to your fish.
Nitrifying bacteria break down Ammonia into Nitrites, which are also toxic to your fish. Nitrites are broken down into Nitrates, which are safe for fish at low levels. High levels become toxic to the fish and plants. They can also cause algae blooms in your water. Guess why so many lakes and swimming pools are green. Yep, Nitrates.
So, if your tap water already contains Nitrites and Nitrates, you are potentially using water in your aquarium that is toxic to your fish. See the issue here? Whenever you add more tap water to the aquarium, you are adding more Nitrites and/or Nitrates and increasing the concentration.
There are some solutions to water issues, but this will add some expense to your hobby. Above I mentioned that well water may be “hard” water. A solution to this would be adding a water softer. Yes, I said that water from a water softener is not a best practice. However, a solution to this is to take that water and run it through a Reverse Osmosis unit to remove the salt from the water. RO will also remove Nitrates and Nitrites and a host of other dissolved solids. RO systems can also include a deionizing (DI) filter which will remove virtually all dissolved minerals from the water, making pure water. You will need to add some minerals back to this very pure water to make it habitable. There are a few options available such as Seachem Equilibrium or Kent Marine RO Right. Do some research.
There are many RO DI systems on the market. My water come from a municipal well, so is a little harder. I bought a system from Koolermax last year from Amazon. I’ve not yet set it up, but I’m looking forward to it. My main use for it will be drinking water, with some water used to replace what has evaporated from my aquariums. RO is good water to drink. DI water is generally considered to not be. The Koolermax system has two outputs, so one for drinking (RO) and the other for the fish (DI).
One of the tests I mentioned is pH. This is how acidic or alkaline your water is. The general wisdom is that you shouldn’t try to change the pH of your water. Your aquarium is not a swimming pool and any rapid changes in pH will weaken and perhaps kill your fish. Just test the water you will be using and get fish that can tolerate that pH.
If your water is going to be too much of a hassle to get sorted out, there are other options. You can purchase RO and/or DI water from many local fish stores for not very much money. I’ve also seen RO water available at the local supermarket as drinking water dispensed from a machine that allows you to fill your own water jugs. The most expensive solution I’ve found is CaribSea Aquatics Ready-Water Purified Freshwater at $23.47 per 4.4 gallon container. It might be ok for a small aquarium, but I don’t want to spend $300 for water for my 55 gallon, plus however much to do water changes and keep it topped off.
Another thing to consider with the water you will be using involves chlorine and chloramines. These are chemicals added to municipal drinking water to keep the water safe to drink as it travels to your home. Humans and other mammals are able to handle the low levels of these without much trouble. They unfortunately will kill your fish. The good news is
Finally, you will be doing water changes. This is mandatory. I mentioned Nitrates earlier, and when they build up to a certain point, you will start losing fish. The best way to remove Nitrates is to do water changes, preferably on a schedule. Once you have your aquarium up and running and have fish swimming around, you will need to test at least weekly to see the Nitrate levels. The test results will let you figure out when to do a water change.
When I say water change, I don’t mean replacing the entire aquarium’s worth of water. It is normal to do a 10% or 20% water change at a time. Any more than that and you can cause large fluctuations in water chemistry and fish generally don’t like that. You should do a 20% water change at least monthly, but it is usually better to do a smaller 10% change weekly, or perhaps twice a week. Your aquarium is unique, so you should test your water often and figure out a good schedule. Your fish will appreciate it.
Fish Keeping, part 1
Fish Keeping, part 2
Fish Keeping, part 4