What is the Best Water to Use In a Fish Tank

Have you ever wondered what water is the best for use in an aquarium? I myself didn’t really think much about the water problem that I would use to raise fish because I would definitely use PAM water. If you don’t know PAM water, it is water that comes out of the faucet at home and we usually use it every day.

Until some time after making the first aquascape, I started to get information about various types of water that can be used for aquariums. But, if you ask me what is the best water to use for an aquarium? My answer is PAM water.

In this article, I will share information about various types of water that can be used for aquariums and the reasons why PAM water is the best water to use for aquariums.

Types of water that can be used for aquariums

PAM water

PAM water is the fastest source of water and almost everyone has at home. Because the access can be said to be very easy, PAM water is the first choice that can be used for aquariums. Of course, the condition of this PAM water can vary depending on the location of the house and the water source used.

Usually PAM water contains chlorine or chlorine which is used to clean the water. Actually this chlorine or chlorine can harm fish, therefore some people look for other alternatives. To remove this chlorine is very easy, the water to be used is enough to be left for a day or two before use, the chlorine content will disappear by itself.

This is what I do before using PAM water, the day before changing the aquarium water I will prepare the water in a bucket and use it the next day. Of course this is not too much trouble because most of my aquariums are small and don’t require a lot of water.

But what if the aquarium is large enough to require a lot of water? The first way that can be done is to use a larger bucket so that it can store more water. Another way is to use a dechlorinator, which is usually a liquid and can remove chlorine.

So if the water flows directly from the faucet because it requires a lot of water, you can immediately add a dechlorinator as soon as the water is in the aquarium.

Well water

If you don’t use PAM water, the second choice usually falls on well water. Because well water comes from the ground, the mineral content (magnesium, calcium, and iron) and pH can be high or low. This mineral content and pH depend on the location of the well, so if the location is different it may have different content as well.

Because fish are very dependent on water to live, so fish are very sensitive to their environment. Indeed, most fish can adapt to the environment they live in, but if they are too far from their comfortable habitat, the chances of fish surviving will decrease.

For example, betta fish like water pH between 6.8 – 7.5, but it turns out that well water has a much more alkaline or acidic pH than where betta fish usually live. This will make it difficult for betta fish, even if they can adapt, of course not all betta fish will be able to.

So you should find out the needs of the fish before keeping the fish. If you already know what pH fish prefer, just match it with the condition of the well water you have. If it turns out far, you should not use well water.

Mineral water

Mineral water actually mostly also comes from springs, and possibly also from underground. But the difference with well water is that the mineral water company has already filtered the water. This filtration can be done by reverse osmosis (RO) and deionized so that it will remove bacteria and mineral content in it.

After the removal process, mineral water is added with minerals according to their standards. So the mineral water content of each brand will be different. The pH content of each mineral water is also different, for example Cleo’s water tastes a bit bitter because the pH is quite low.

Don’t forget that mineral water must also use chlorine, so if it is used for an aquarium, it also needs to be silenced or use a dechlorinator. In addition, money is needed to buy this mineral water, which may not be a small amount if you have many aquariums or are large in size.

So if you really want to use mineral water, you have to spend money to buy it, then check the mineral content and pH of the water, then because it contains chlorine, you have to either leave it on or use a dechlorinator.

Reverse osmosis (RO)

Maybe this is the water that is said to be the best used for the aquarium. For some cases, RO water is very good for aquarium use. But you have to be willing to be a bit bothered if you want to use RO water.

Why bother? Because basically RO water has undergone a filtration process so that it removes almost all the minerals in it. In short, the water content is pure H2O and no other minerals. Unfortunately, fish and plants need not only H2O, but other minerals to live.

This is the main reason RO water is not good if used without doing other processes. If you want to use RO water, you must give back essential minerals beforehand. The reason why RO water is good for aquariums is because the water is pure and there are no harmful substances for fish.

Because the water is pure, it is necessary to remineralize or give minerals as needed. In addition, you can adjust the desired pH yourself if you use RO water, so you can adjust it to the best conditions for fish.

Then what happens if RO water is used directly? Because there are no minerals in it, it will be harmful to fish and plants. In addition, because there are no minerals that can help regulate pH, the pH conditions of the water can change drastically and be dangerous for fish.

RO water is more often used for seawater aquariums because seawater fish are sensitive to salt content in the water. Because there are no minerals at all, then by adding salt the RO water is ready to use. In addition, to prevent changes in salt content due to evaporation, RO water is also used to add water loss to maintain dissolved salt content.

So if you are not ready to do remineralization because you use RO water, you should not use RO water. In addition, to get RO water, of course, you have to buy and spend money. Or make your own RO water which will certainly cost money to buy the equipment.

Water from refill depot

I personally have never used refill water either for daily needs or for aquariums. From the brief information search that I did regarding this refilled water, there may be a choice of RO water or mineral water or just one.

If it is RO water that is being sold, remineralization must be carried out before use because RO water only contains H2O and no minerals. But if what is used is mineral water, it is possible that it can be used immediately. But if you want to be very sure, you should check the pH of the water to match that required by the fish to be kept.

So, the best way is to ask the water refill depot what kind of water they sell. Of course, using water from a refill depot means you will spend more money.

Why is PAM water the best for aquariums?

Easy to get

The first reason is because PAM water is the easiest to obtain because it is readily available at home. Because it is already available, there is no need to bother looking for or spending more money to buy water. Although using PAM water also means paying, the use of PAM water is not only for aquariums but for daily needs as well.

In other words, using PAM water can also save expenses. It’s a different story if you have a seawater aquarium, maybe using RO water is a must.

No hassle

Unlike RO water, which must be added to minerals before use, PAM water does not require this. It may only take a day or two to remove the chlorine or chlorine, or you can use a dechlorinator.

Stable water content

Water conditions are very important for fish to live. It would be better if the water conditions have a stable mineral content and pH and do not change drastically.

Using RO water means having to replenish the minerals lost due to the filtration process. So the mineral content and pH must always be the same when changing water. Because if the mineral content changes drastically, it can cause fish to be shocked and then stressed, and it is possible to cause death.

If PAM water is almost certain the results will always be the same because it has gone through many processes and has standards before being distributed. So the risk of changes in water conditions can be minimized.


The quality of PAM water in each region may be different, coincidentally in my area the PAM water is safe to use for raising fish. Therefore PAM water is the best choice for me to use. If in your area PAM water conditions are not suitable for raising fish, you may have to look for other alternatives.

Another alternative is RO water, but you have to be willing to spend more money to buy water and also buy equipment to replenish lost minerals. If there is no RO water, maybe you can try refilled water, but you must also ask the condition of the water whether it contains minerals or not.

But I believe that the current condition of PAM water is good and evenly distributed in every area. Because PAM water is the easiest and readily available option, it is the first choice to use.