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It is not an issue for most aquarium fish species to live in tap water. However, I don’t recommend you to just pour that tap water in the tank. You need to use a water conditioner first to make it safe for your fish. Plain tap water can be deadly to your fish because there are no beneficial bacteria in it to help break down the waste.
The quality of tap water can also greatly differ depending on where you live. In some countries, it is barely drinkable for people and it is even worse for pets. It can contain contaminants such as fluoride, metals and chlorine.
Also, the fish comes with some water when you buy it and that water has its own chemistry. If you would put the fish into plain tap water, it would be a huge difference. This dramatic difference in water parameters can cause a lot of stress to your fish.
So, if you want to use tap water in your aquarium, then pour it in the tank and just let it sit there for a few days. Then, you can start adding fish one by one while carefully watching the ammonia and nitrite spikes in the water.
What is a Water Conditioner?
If you plan to use tap water for your aquarium, then it is really important to get a water conditioner. In tap water, there are certain minerals, metals and chemicals that are not safe for your fish. Such conditioners come in liquid form and all you need to do is to pour them in the water.
The main goal is to remove the chloramine and chlorine contained in it. These are actually helpful chemicals for us humans, as they make the water safe to drink for us. However, they are dangerous for pet fish because they can die in untreated tap water.
On a molecular level, what happens is that ionic bonds will form, which basically neutralizes the toxic chemicals.
How to Use a Water Conditioner?
Water conditioner has to be used every time you are about to pour tap water in the tank. Therefore, you not only need to use it when you set up your new tank but also when you perform a water change. You simply need to mix the conditioner with the tap water and it will do the work for you.
Look for the recommended dosage in the instructions that come with the bottle. Once the water is ready, you can pour it in the aquarium. The best way to mix it together is to add the dosage to the water while it is coming out of the tap.
This way, you can pour that water in the tank right after you ended up with a full bucket. For a new aquarium, I recommend you to use a basic dechlorinator, which is a type of water conditioner. It is going to neutralize the chloramine and chlorine while leaving the ammonia content as is.
You are going to need that ammonia for some fishless cycling, as it helps the beneficial bacteria to form. The best water conditioner you can use for it is the Seachem Prime concentrated formula. A little bit of this cost-effective conditioner is enough to get your tap water ready for the aquarium.
It does what you can expect from a water conditioner, which is neutralizing chloramine and chlorine. However, instead of neutralizing ammonia, the formula converts it into a safer form. It also makes sure that metals found in tap water become harmless.
At last but not least, the Seachem Prime will make sure that the slime coat of your pet fish will regenerate faster.
Don’t Forget about Nitrogen Cycle
Before you introduce the fish into the aquarium, you need to do proper cycling. This is a process that every fish tank has to go through in order to end up with colonies of beneficial bacteria. Those bacteria are going to make sure that the nitrogen cycle does not get out of hand.
When ammonia is generated in an aquarium, it gets converted to nitrite and then to nitrate. This process has to be regulated by bacteria otherwise the water becomes toxic to your fish. The process of cycling includes slowly adding fish to the aquarium.
You don’t want to add them all at once because that would be a huge bioload. Those bacteria need time to establish and they can’t deal with that much ammonia at first. Let that tap water sit there with a couple of fish and a filtration system installed and add more fish over a few weeks.
Weekly Water Changes with Tap Water
It is very important for every fish keeper to perform weekly water changes to freshen up the aquarium a bit. Make sure that 10-20% of the water is replaced in the tank once a week. If you use tap water for it, then don’t forget to treat it with a water conditioner before you pour it in.
Another thing that is important is the temperature. There is a recommended water temperature for every single fish species. If it’s colder or warmer than that, it causes a lot of stress to them and weakens their immune system, eventually making them sick.
It would be quite a shock for your fish if you would pour some cold water in the tank. Instead, you need to make sure that the water you are about to use has the same temperature as your aquarium water.
The conclusion is that using tap water is actually not a bad idea if you want to set up a new aquarium. All you need to do is to make that water safe for your pet fish and do some cycling. The best way to do this is to choose a water conditioner and mix it together with the tap water.
In my experience, Seachem Prime is one of the best products that can neutralize the potentially toxic elements in it. Don’t forget that tap water is great for weekly water changes too, although it also has to be treated with a water conditioner.
It might seem like a fancy thing to buy because tap water seems completely harmless. As we discussed, there are plenty of harmful chemicals in typical tap water so it is very important to prepare it the right way.Fishkeeping