Need advice with hard water

[Sanniejop]

Hi all,
Ok, I understand that the hardness of water is important. Ideally it should be 6 or lower(?)

My tap water has an KH of 11. ICP analysis of water supplier tells me it contains Ca 56 ppm, Mg 6 ppm and K 2.6 ppm.

When i want to keep using this tap water as is....
To which ppm values should i dose Mg and K with these Ca and hardness numbers?
I understand that the ratio between those three is important. But is it wise to increase the Mg and K values to meet the ratios with the high Ca or should i keep them lower?

Or is it really worth to invest in RO unit? And all the hassle coming with it.

Thanks in advance,
Greetings Sandor

 

[dw1305]

Hi all,
Welcome to UKAPS, we have a few members from the Netherlands.

Or is it really worth to invest in RO unit? And all the hassle coming with it.

Is <"rain-water a possibility for you">? It has many of the advantages of RO water, but without the environmental footprint etc.

Ok, I understand that the hardness of water is important. Ideally it should be 6 or lower(?)

My tap water has an KH of 11. ICP analysis of water supplier tells me it contains Ca 56 ppm, Mg 6 ppm and K 2.6 ppm.

That is absolutely fine as a water supply, many <"successful planted tank keepers"> will have water that is much harder than that.

I understand that the ratio between those three is important. But is it wise to increase the Mg and K values to meet the ratios with the high Ca or should i keep them lower?

Personally I'm not to bothered about ratios, @Happi may be able to give you a more nuanced reply. You will be adding potassium (K) and magnesium (Mg) as part of <"your fertiliser addition">, but you don't need to add any more calcium (Ca).

cheers Darrel

 

[Happi]

@Sanniejop
do you have a full Report from the ICP analysis of your water? also the report from where your tap water comes from?

 

[Ria95]

Hello,
in summary I think you will be able to grow a wide variety of plants without issues in your current tap water. No need to dose extra calcium or magnesium. I would still strongly recommend testing GH (water hardness) from your tap to see if you are in the same ballpark as the water company analysis.

K will usually come from your macronutrient fertilizer. If you are dosing EI it will come in more than sufficient quantities from there. Plants are adaptable, no need to be fretful about deviations from proclaimed optimal ratios.

A lot easier to keep things simple and have fun growing plants .

 

[Happi]

the term ratio would be good for those who are into experimental, but it is not mandatory for regular hobbyist.
"Ca 56 ppm, Mg 6 ppm and K 2.6 ppm" seems like there is plenty of Ca and Mg, if anything you can bump the Mg to 8 ppm or so, the K will be added through Macro or you can choose to add it at water changes, probably best to use it with your Macros. my only concern is high KH of 11

 

[arcturus]

Hi all,
Ok, I understand that the hardness of water is important. Ideally it should be 6 or lower(?)

The general hardness of the water GH measures total Ca and Mg. Recommended values are dGH > 6, especially if keeping invertebrates. Plants thrive over a wide range of GH.

The carbonate hardness KH measures dissolved carbonates. Plants are more sensitive about KH values than GH values. You can grow most plants with a low KH (say less than 5-6° dKH). Above this value sensitive plants can start to have issues. dKH can be kept near zero. However, water with lower dKH values will have less pH buffering capacity.

My tap water has an KH of 11. ICP analysis of water supplier tells me it contains Ca 56 ppm, Mg 6 ppm and K 2.6 ppm.

Are you talking about KH = 11° or GH = 11°? A GH of 11 is ok. A KH of 11 not so much, but it all depend on what type of aquarium you want to keep. Can you please check and report the KH and GH levels of your tap water? The Ca and Mg are fine (and can be easily increased if needed). The K will also be adjusted to the target range by your macro fertilizers.