Water Cal/Mag ratio

[Wacky Wardrobe]

Just now, mysticriver said:

I understand then that there is ~20ml/l. Of calcium.

??

I read that as just shy of 300 milligrams per litre.

 

Hopefully our resident guru will step in about this point. # @Oldbear :-)

[Wacky Wardrobe]

Just now, Oldbear said:

I can't see any mg values,

@Periodic posted this the other day:

 

"I rang them  (Severn Trent) up and asked the Ca/mg in my area, (Sth..Leics.)

the technical people rang back and it is  5/3 Calcium to magnesium,"

 

A bit vague but could be helpful if true.

Seems a lot of mag. If you added cal to balance you'd end up with sky high base ec by my reading?

[Wacky Wardrobe]

@mysticriver Get it tested buddy!

It will no doubt pay dividends in the long run and save a lot of hair pulling.

I may well get mine done too.

Tag me with an update as I'm curious :-)

All the best.

[Periodic]

Thanks for the replies,

e.c. is already .5

I was using a proportion  of R.O. water but my filter got frosted and cracked,

replacement on the shopping list.

 

The water samples are taken from consumers houses, and nothing I'm interested in gets altered between the resovoir and here, the stalactites on the taps testify to the "rock" content.

 

Must reiterate the lady at S.Trent seemed happy to talk "water" all day and there are plenty of legal crops needing watering so  I called them it's their "product".

[mysticriver]

So what would I have to do/add to get this tap water up to the desired 3:1 ratio?

Anything @Oldbear & @Wacky Wardrobe

 

Actually, and this has all happened since I started this post - Im leaving this area, been here 11 yrs, ive finally had enough of the noise and anti-social neighbours all around me (I call this estate Asbo-Central). Its probably a lot worse than any of you can imagine. Its a well known estate that I dont want to mention fr obvious reasons. So in the past few days ive decided to move and im just waiting for the right house to come up on Rightmove/Zoopla etc in the area I want to go to. Which is another (much nicer) satellite estate of the town where im from, a mile or two over. So the water may be slightly different there. Ive noticed that water tastes different in different parts of the area and this particular supply where I live right now is total WRANK - I DONT DRINK IT. It tastes bad.

When I land at the new place ill get a test report on the water and know for sure.

Im gutted cos as I decided to move I found the perfect house, which had just been let. If only I had decided a week sooner.

 

mysticriver 

Edited October 26, 2021 by mysticriver
to add some rambling nonsense

[Wacky Wardrobe]

8 minutes ago, mysticriver said:

So what would I have to do/add to get this tap water up to the desired 3:1 ratio?

I think adding anything to your water to correct the ratio would result in a really high base ec from my understanding.

You may be into RO territory to achieve the optimum.

I think you should go for getting it tested and see what's recommended.

It's going to be well worth it for you in the long run I reckon.

[J.C]

Decided to get mine tested too so I could be sure of any issues. Just got this back:

 

we have tested your water, results and comments below. Values are in parts per million (ppm) except pH.

Calcium           79.2

Magnesium     1

Sulphate          57

Alkalinity          219

pH                    7.35

 

This is a hard water with moderate to high levels of Calcium and Alkalinity but very low Magnesium values, the sulphate level is good.

The imbalance between the Calcium and Magnesium means that even when Hard water food is used the Ca:Mg ratio is outside the good range. For best results you will need to either add some extra magnesium or order a custom nutrient. the amount of Mg needed will depend on the growing media used, let us know what you are growing in and we can calculate it for you.

 

I've replied back to them but thought I would see if anyone on here has any suggestions on how to "fix" my water?

 

Cheers.

[SYZYGY]

@J.C Hi mate

 

Adding 3.7 ml of Canna Mono Mg to 10l of your water would bring your ratio to 3:1 (79.2 Ca : 26.9 Mg). 

 

Your alkalinity is quite high and may be a cause for concern. 

 

I was confused about the difference between pH and alkalinity until I read this:

 

Water alkalinity and pH are not the same. Water pH measures the amount of hydrogen (acid ions) in the water, whereas water alkalinity is a measure of the carbonate and bicarbonate levels in water. Think of carbonates and bicarbonates as dissolved limestone. The higher the alkalinity of the water, the more lime it contains and therefore, the more rapidly the water can cause the growing medium pH to rise. On the other hand, the pH of the water does not have any influence on the pH of the growing medium.

Starting Water pH	Water Alkalinity (ppm CaCO3)	Sulfuric Acid Required to Reduce Water pH to 5.0 (ml)
9.3	71	1.2
8.3	310	6.0

For example, the chart above shows the starting pH of two water sources and the amount of acid required for each to reach a pH of 5.0. The water with the higher pH did not require as much as acid as the one with the lower starting pH. At first glance, this may not make sense.  However, note the alkalinity in the center column. Regardless of the starting pH, the higher the alkalinity of the water source, the more acid is required to reduce pH to 5.0. For all water sources, it is the alkalinity that actually determines how much acid to use, not the pH

How does water alkalinity influence the pH of the growing medium? 

In the graph below, vinca plugs were grown for 49 days and constant fed with the same fertilizer at 125 ppm. The plugs were irrigated with three different water sources with varying alkalinities. The pH rose in all three media samples partially due to the fertilizer used and the limestone in the growing medium. However, the higher the alkalinity of the water source, the higher the pH of the growing medium.

This graph shows influence of the water alkalinity on the pH of vinca plugs after 49 days. Notice the higher the water alkalinity, the higher the pH of the growing medium rose after 49 days. Data taken from: D. Bailey & P. V. Nelson, Substrate pH and Water Quality. 1996 Ohio Short Course

It is clear that the pH of the water and the alkalinity are not the same. In fact, the pH of the water does not dictate the pH of the growing medium, but in fact it is the alkalinity of the water source that influences the pH of the growing medium. This is important for growers to know, since alkalinity has significant impact on growing medium pH, when choosing the correct fertilizer(s) and/or injecting acid.

[J.C]

Just now, SYZYGY said:

@J.C Hi mate

 

Adding 3.7 ml of Canna Mono Mg to 10l of your water would bring your ratio to 3:1 (79.2 Ca : 26.9 Mg). 

 

Your alkalinity is quite high and may be a cause for concern. 

 

I was confused about the difference between pH and alkalinity until I read this:

 

Water alkalinity and pH are not the same. Water pH measures the amount of hydrogen (acid ions) in the water, whereas water alkalinity is a measure of the carbonate and bicarbonate levels in water. Think of carbonates and bicarbonates as dissolved limestone. The higher the alkalinity of the water, the more lime it contains and therefore, the more rapidly the water can cause the growing medium pH to rise. On the other hand, the pH of the water does not have any influence on the pH of the growing medium.

Starting Water pH	Water Alkalinity (ppm CaCO3)	Sulfuric Acid Required to Reduce Water pH to 5.0 (ml)
9.3	71	1.2
8.3	310	6.0

For example, the chart above shows the starting pH of two water sources and the amount of acid required for each to reach a pH of 5.0. The water with the higher pH did not require as much as acid as the one with the lower starting pH. At first glance, this may not make sense.  However, note the alkalinity in the center column. Regardless of the starting pH, the higher the alkalinity of the water source, the more acid is required to reduce pH to 5.0. For all water sources, it is the alkalinity that actually determines how much acid to use, not the pH

How does water alkalinity influence the pH of the growing medium? 

In the graph below, vinca plugs were grown for 49 days and constant fed with the same fertilizer at 125 ppm. The plugs were irrigated with three different water sources with varying alkalinities. The pH rose in all three media samples partially due to the fertilizer used and the limestone in the growing medium. However, the higher the alkalinity of the water source, the higher the pH of the growing medium.

This graph shows influence of the water alkalinity on the pH of vinca plugs after 49 days. Notice the higher the water alkalinity, the higher the pH of the growing medium rose after 49 days. Data taken from: D. Bailey & P. V. Nelson, Substrate pH and Water Quality. 1996 Ohio Short Course

It is clear that the pH of the water and the alkalinity are not the same. In fact, the pH of the water does not dictate the pH of the growing medium, but in fact it is the alkalinity of the water source that influences the pH of the growing medium. This is important for growers to know, since alkalinity has significant impact on growing medium pH, when choosing the correct fertilizer(s) and/or injecting acid.

 

@SYZYGY - Thanks mate, brilliant news as I just rang my local grow shop and they have a stash of the Canna Mono that they don't sell anymore and said they'd do me 1L for £10. Spot on.

[SYZYGY]

I'm experiencing issues which I believe are related to my alkalinity being far too low (mine's 24!). This is from Quantrill who I believe is a good source of info:

 

TABLE 1. ALKALINITY GUIDELINES FOR ICL LAB ANALYSIS. POT DIAMETER/SIZE IMPACTS THE EFFECT OF ALKALINITY.

INTENDED USE	NORMAL RANGE		LEVEL OF CONCERN (U)
	ppm-mg CaCO3 /L	Milliequivalents CaCO3 (V)	ppm=mgCaCO3 /L	Milliequivalents CaCO3
Plugs	60 to 100	1.2 to 2.0	<40. > 120	<0.8. > 2.4
Small pots/shallow flats	80 to 120	1.6 to 2.4	<40. > 140	<0.8. > 2.8
4" to 5" posts/deep flats	100 to 140	2.0 to 2.8	<40. > 160	<0.8. > 3.2
Pots: 6" or more/long term crops	120 to 180	1.6 to 3.6	<60. > 200	<1.2. > 4.0

(U)	Highest level a grower can manage depends on plant type grown, media type, potential acidity of feed program and watering practices. Levels listed in this table are guidelines only!
(V)	Milliequivalents = ppm total alkalinity expressed as milligrams Calcium Carbonate per liter divided by 50.

LOW ALKALINITY: Use a low acidifying or basifying feed program, provide for adequate calcium and magnesium in the constant liquid feed and assure that growing medium lime rate is adequate. 

HIGH ALKALINITY: Use an acidifying feed program and/or add mineral acids to irrigation water such as phosphoric, sulfuric acids. Exercise appropriate precautions when handling concentrated acids and use acid-safe injectors.

[SYZYGY]

31 minutes ago, J.C said:

let us know what you are growing in and we can calculate it for you

 

Worth finding out what Grower's Ark have to say on the matter tho  

[J.C]

Just now, SYZYGY said:

 

Worth finding out what Grower's Ark have to say on the matter tho  

 

Yeah I'm going to see what they say, I've got to head out later anyway so for £10 I'll grab that bottle anyway. Do you think my high alkine would be solved by my use of pH Down? Or is it not as simple as that?

[SYZYGY]

Just now, J.C said:

Do you think my high alkine would be solved by my use of pH Down?

 

That's the suggestion from the info I posted on the last page, but my understanding is purely academic as I have zero experience growing with hard-as-nails water. 

[J.C]

2 hours ago, SYZYGY said:

 

That's the suggestion from the info I posted on the last page, but my understanding is purely academic as I have zero experience growing with hard-as-nails water. 

 

I really appriciate the information, I'm going to see what adding this Canna Mono does and react if I need to.

 

Cheers

[catweazle1]

On 21/10/2021 at 1:07 PM, BilgePump said:

Ok so that water test has piqued my interest , at 30 quid that could save hours of headaches.

My water is stupid soft but the exact make-up isn't easy to determine from the South West water website.

 

 If it's that soft, can't you ignore it and add the Ca/Mg to your desired ratio?