What Kind Of Water Should You Use For Your Bonsai?

Watering your bonsai is a fundamental part of its survival, if you don’t get this right your tree will die …but does it matter what kind of water you use?

The truth is that it doesn’t really, of course some types of water are better than others, but so long as your tree is getting what it needs it should be fine.

I will go through some different types of water you can use and some that you should avoid. 

Does It Matter What Type Of Water You Use For You Bonsai?

What type of water you actually use isn’t that important. So long as your tree is getting enough water, it should be happy.

You really need to know How To Water. Mastering this is much more important. There is no point having the world’s best water if you don’t know how to give it to your tree.

You will also find that for some reason this topic is quite controversial. People like to argue that some water sources are ore superior than others, and while there can be some truth to that, the reality is not quite the same …as I said, so long as the tree is getting enough water, that is all that really matters, so let’s go through the different types you can use.

Rain Water

Rain water is always going to be the best type of water for your trees, and most of the time you can’t really stop it anyway.

Rain is going to come and your trees are going to get watered. It is totally natural and it really is the best type of water for you trees.

I know some people worry about other things being in the rain, but its fine. Rain will contain other various particles but these are not going to harm your tree, it’s all natural and your tree will thrive from rain water.  

Collecting Rain Water

A lot of people like to collect rain water and this can be a very good idea, especially if you are using a watering can as your main watering tool and if you have dry summers without much rain.

It can be very easy to set up a rain barrel and connect it up to some gutters and very quickly have a large barrel full of water that you can use to fill up your watering can.

There can be some concern about this water going stagnant, but this shouldn’t really be a problem. So long as you have some sort of cover over the top this will stop debris getting in and also stop insects like mosquito from taking over.

Tap Water

People often get funny about using tap water on their bonsai, which is kind of strange to me. This water should be safe to drink, so it should not cause your trees any issues.

I think the concern is that tap water can contain other things, such as fluoride, but I guess this depends where you live and since its “safe” for humans it should still be fine for your trees.

The hardness of the water can also be an issue for some people, but I will cover this aspect in more detail below.

I have pretty much only used tap water for a large number of my trees and they have been totally fine and very healthy. Tap water is okay for your bonsai and to be honest, it can make things easy as all you need to do is turn the tap on and water will come out of your hose.

What Type Of Water Are Most People Using?

Rain water and Tap water are the two most commonly used types of water and before we go on to look at some other types of water, I thought I would ask my subscribers what they use, and here are the results:

A you can see, tap water was the most common with 55%, I would imagine this is due to how easy it is to use. However, 32% use a combination of both, so really 87% of bonsai growers are using tap water.

When I said before that people get funny about using tap water, they are clearly in the minority, with only 13% using only collected rain water, but it does show that they are out there.

Using Water From Streams, Rivers or Lakes

Using any sort of water from streams, rivers, lakes, creeks or ponds is going to be fine for your bonsai.

I would suggest that it is maybe not the most easily accessible water source you could use as you are going to have to transport the water somehow.

I guess you would have to dunk your watering can in and then carry it back to your trees. However, if this system seems to work for you, then go for it, it will not harm your trees in any way to use this type of water. 

Using Bottled Water

You could use bottle water, this would be fine, but at the same time I really have to question why!

Trees need a lot of water and the price of bottled water will start to add up, but if you can afford it, I’m not stopping you.

I just think there are more easily available (and free) sources of water you can use for your trees.

Using Water From Fish Tanks

There are always questions asked around using fish tank water on your bonsai. The theory is that fish tanks will need the water swapped because its nitrogen levels get too high from all the fish poop …but trees like nitrogen …so it’s kind of like natural fertiliser water and instead of throwing it away this could be used to water the trees.

I guess there is some sense to this, the water will be more nitrogenised from the fish, but will this help the tree …I don’t know. I don’t know if this nitrogen can be used by the tree and I don’t know if there is anything else that might be missing from the water that the tree may need or want.

However, any one does this, doesn’t seem to have an issue. They all say it is great and their trees are healthy. It is unclear if this actually benefits the tree, but it’s certainly doesn’t harm them, so if you want to do this, give it a go and let me know how you get on.

Using Distilled Water

Using distilled water may seem like a good idea, but I don’t think it is. Distilled water is basically pure water. The distilling process removes all the impurities and you are just left with H2O.

You can buy the water like this, or you can have a system at home that will do it for you, such as a reverse osmosis system that is common with fish keepers.

This water isn’t going to be “bad” for your bonsai, but having all those extra minerals removed isn’t ideal. The tree will use a lot of these and it can help keep the bacteria in the soil happy too, so having them missing is probably not the best.

Of course you could add fertiliser and what not to restore a lot of these, but then what would be the point of removing them all in the first place?

When you look at water from every other source, they will have these minerals …even our drinking water has (this is what spring water is) so I think it is a lot more natural to just keep these things in the water and let the tree use what it needs.

Does Water Hardness Matter?

Water hardness is something we worry about, but honestly, when it comes to the trees health it isn’t the biggest deal.

Water hardness is really the measurement of minerals within the water, especially things like calcium. The more there is, the “harder” the water will be.

Having lived in both hard and soft water areas, you can taste a difference, but it seems to make no difference on the trees.

The only issue you will suffer is the white crust on your pots. The harder the water, the more likely you will get a build up on the rim of your pots. This is harmless, but ugly and luckily it is easily removed.

I wouldn’t worry about the hardness of water, just use what you have got. It’s is going to take a lot of effort to start trying to change this and really you are going to need to use distilled water, which as I have discussed above is kind of too “pure” …just leave the water as it is.

(You can read more about – What Is The White Crust On My Bonsai Pots?)

Does Water PH Matter?

PH is something that people worry a lot about in bonsai, and I think there is some sense to this, but at the same time we do seem to go over the top.

The general PH of your soil can matter, but really you just need to know if your tree likes a slightly more acidic soil and then use a soil that can cater to that. I don’t think you need to worry about it anymore than this.

When it comes to water, I really don’t think we need to worry. The PH of your water should be 7, which is neutral, but due to whatever minerals are in it, along with some carbon dioxide being absorbed, it can vary a little. Some water may be slightly more acidic, while others more alkaline.

I don’t think the deviation from PH7 is big enough for us to worry about. If you look at the water we drink, it can also swing either side of this …and it does us no harm.

I think getting out the measuring strips and trying to work out what PH your water is, is way to over the top.

Just use whatever water you have, and it should be fine.

What Kind Of Water Is Bad For Bonsai?

While a lot of the water you can find is going to be acceptable for you trees, there are some types of water you should avoid.

Salt Water

Salt water should be an obvious one, but if you are not aware, salt water is not good for plants and you will very quickly kill your tree by using this.

You do not need to worry if you live near the beach, there is no risk …unless for some reason you decide to fill your watering can up with sea water and pour it all over you trees.

Stagnant Water

While stagnant water shouldn’t really harm the tree, just don’t use it. Most of the bacteria should be harmless to the tree, but you never know what is in it.

It is also going to be smelly, so do you really want to be going near that and then pouring it all over your lovely trees. 

I would just stay away from it unless there was an extreme emergency.

I know some “fertilisers” like worm juice can stink, but these are more fermented and are actually good for the tree, whereas you can’t be too sure with stagnant water so I would just leave it alone.

Other Liquids That Are Not Water

Really if whatever you are planning to use is not water… don’t use it. Just because it is fine for humans to drink, it doesn’t mean it good for you tree, so avoid the tea, coffee and any other soft drinks. They are all going to have extra things in them mixed with the water and you just don’t know how the tree will react to these, so avoid it.

Then of course if you are using any sort of liquid chemical that isn’t water… this will end badly. Finding a random bottle of white spirits may look like water …but you tree will not be happy. The rules are pretty simple …If it isn’t water, don’t use it.

Conclusion

Hopefully that helps you understand that you do not need to worry too much about you water. Just use what you have access to and it should be more than suffice.

I would focus more on getting your watering right and making sure your tree has enough. This is more important than the “quality” of the water …and really, so long as it is water, and not anything else, your tree will be more than happy with it.   

(You can read more about – Frequently Asked Questions About – Watering Bonsai)