Updated: Jan 7
A lot of people with a Bonsai Collection will water with the town water straight out of the garden hose, But to avoid problems we need to test our water to make sure it falls within the parameters that are safe for plants.
Water quality is something that is over looked in many many bonsai collections around the world, it is something that just simply isn't given any though because we tend to think that if the water is good enough to drink then it is good enough to water our trees with, but this is actually not true and quite the opposite.
Water that is healthy for human consumption is borderline unhealthy for trees. But why do i say borderline? its to do with the PH of the water. Town water is treated and the higher the PH the better it is for humans, But the standard is between 6.5 - 8.5 in most places. In saying this most water suppliers will try to get the water somewhere around 7. Plants do best at a PH level of 6 - 6.5 so as you can see a level of 7 is slightly Alkaline for a trees liking. A PH level of 7 though is fairly decent from the town waters I've tested here in Australia, usually it is higher. A PH level of 7.5 or higher and you will need some intervention to your water.
So now that we have got that out of the way there is a few questions that you probably have now that need answering such as
What effect does a higher PH higher then 6 - 6.5 have?
How do i test my water?
what can be done to correct this?
So lets go through and answers these 1 at a time.
First lets look at how to test your water.
This is very simple, Almost all pet stores carry PH test kits for fish tanks. All you need to do is purchase one which here in Aus will cost you around $15 - $20. In the kit you will get 3x bottles of solution, a test tube and a PH card. Now 2 of the solutions you wont need which will be the PH up and PH down solutions which are used to correct the PH in a small fish tank. All you will need is the testing solution. Once you have your test kit collect some water from your tap and mix it with the test solution following the manufacturers instructions.
The water will change colour and you can match this up to the colour on your PH card to determine what PH your tap water is.
Now lets discuss why we need to keep our PH levels in check.
When we have alkaline water at a higher level this can reduce the amount of minerals and nutrients the root ball can take in. Your tree will struggle to take in Phosphorus at a higher PH reducing root growth and fruiting and flowering, But on top of this high PH can also reduce the amount of micro nutrients taken up such as magnesium which is one of the main elements of chlorophyll which is what gives us our colour in our leaves, so if you have this deficiency you will have reduced colour in your leaves which will lead to a sick looking tree.
Another problem i commonly see is at these higher levels you get a coating of limescale on your Bonsai pots, benches and leaves if you are someone who waters their foliage as well as the soil. Limescale is the minerals from the treated tap water that is left behind after the water has evaporated which is usually calcium. Now this isn't a major problem for your bonsai pot or benches as this can add some patina which for some might be desirable, but this can be an issue for your foliage because a layer of calcium build up on the surface of the leave could block the Stamata in the leaf and reduce the photosynthetic efficiency of the leaf slowing down your trees ability to create glucose for food.
So now that we know the problems that can arise how do we fix it?
Well the simple way is to obviously collect rain water and water your tree with this instead. If your someone who has a water tank consider watering with that water instead of town water.
Failing that you can purchase 1000L water tanks known as an IBC and attach a small pump to disperse the water.
For areas that don't get a lot of rain to fill the tank constantly you can fill it with town water then purchase some PH down solution to treat the water before watering your trees.
I understand how this can be annoying but if your water is above 7.5 this may greatly improve your collection by allowing further nutrient uptake in your trees.
I want to point out as well that if you have water that is between 6.5 - 7.5 it isn't going to kill your trees, but the more you improve the PH level the more you will see your trees improve in health and quality.
I hope this has helped you understand your water conditions a little more and will help you get just a little more health for your trees.
Until Next Time, Enjoy Your Bonsai Journey.