Had GA water report done, How much Mg do i need to add

[Subutai]

Hey, i finally got around to getting a water report done by GA.

 

Here are the results

 

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

 

Calcium        104

Magnesium   4

Sulphate       63

Alkalinity       317

pH                 7.65

 

This is a very hard water with high levels of Alkalinity and Calcium moderate sulphate and low Magnesium.

This water will need a hard water feed.

Due to the high Calcium and low Magnesium even with a hard water feed the Ca: Mg ratio of food plus water will be outside of the good range, how far out side depend s on the feed type (coco, hydro or soil). It will be possible to add extra Magnesium to rectify this again the exact amount depends on feed type but we are happy to calculate this for you if you let us know what food type you are going to use.

 

I have replied, so hoping they get back to me with how much Mg i need to add, but does anyone have an idea? @Oldbear (sorry to ask but you seem to be good at this)

 

Growing in soil and have a bag of Epsom Salts at the ready

[Pot of soil]

Hello mate I think yours report is the closest to mine that ive seen yet so very glad Ive seen this thread.

 

Calcium           102

Magnesium     1

Sulphate          69

Alkalinity          189

pH                     7.4

 

Im growing in allmix with intense organix atm and im going to have one more go in it but with the bio biz nutes  before I switch to hard water coco nutes from growers ark myself.  I just want to get it right once in the old compost.  

 

Kindly advised to add 2 grams of epsom salts if not 3 grams  as I have a deficieny to every 10 liters of water so 0.2 to 0.3 per liter.  So will go with that. 

 

Hoping with that one adjustment will make this next one a good one

[Gaijin]

 me too, but zero Mg

 

Calcium       100 ppm

Magnesium   0  ppm

Sulphate       8  ppm

Alkalinity      366

pH               7.3

 

They advised me to add 2g Epsom salts to every 10L water. Alternatively they were happy to make up a custom feed that matched my water. Haven't tried that option yet, the epsom is working just fine so far

 

Here's the thread where my results were discussed; there might be something in there that helps  

 

 

[Aphatspliff]

They are brilliant to deal with and I’m sure you’ll have a reply tomorrow mate. Getting a water test is the best thing I think I’ve done in indoor growing. If I’d done it from the start I don’t think I’d have encountered half the problems that I have done

[Aphatspliff]

A little tip incase you didn’t know as well, when filling ya water bucket/tank, fill half a jug with hot water and mix ya Epsom’s in that, then top up the rest and pour in ya bucket. They don’t dissolve properly in cold water 

[catweazle1]

 0.25g/l or 1g to 4l Epsom will give you 32mg/l Mg. If it's in single digits add 2ml. This is based on the MgSO4.7H20 Epsom molecule. 

[Subutai]

Thanks chaps.

I am sure they will get back to me with an amount of Mg to use, but thx to the forum i know it should be around 1g to 4L or 2.5g per 10L

[Pot of soil]

Look at us lot all pulling together for the greater good.  

 

Thinking of a landmatk all of us with the sameish water results might know cos we must be close ish 

 

Cheers for link to your thread @Gaijin will check that out.

 

Shout out to the mathamatian amoungst us @catweazle1

[Gaijin]

yeah, it's good here, isn't it  

 

 

[grower951]

Has anyone got on with their custom feed?

 

if you ring them with your questions they can give you an answer, I find them friendly with genuine good service, instead of forcing products down your throat I found they give you the info and let you decide  

[catweazle1]

My water is 0.7ec. Magnesium is quite good at 32mg/mg. Has a Ca/Mg ratio of 2:1, Ca is around 60mg/L. I add 1ml/L GA Traces + 1ml/L Epsom at 1g/4L +  3ml GA Coco AB + 2ml Maxicrop brown + 10% Acetic acid for down to 5.8ish. EC ends up about 1.5. Not bothering with silica this time, but Solar Green Power has not caused any issues. It's nano-silica and doesn't unduly mess with the pH. I've started GA Coco this session and seems to be the easiest to get the plants happy that I've used so far.

Edited April 21, 2023 by catweazle1

[Slippy One]

@carweazle1 wouldn't you need to add mono cal instead of mg to bring the ratio closer to 3:1?

 

[Goodbloke]

@grower951 I bought their custom 2 part nuits for hydro recirc following a water test.

Good results. 

Excellent company to deal with, very helpful. 

[catweazle1]

@Slippy One I don't know what mono mag is, I've not looked into it. Epsom is a single magnesium ion attached to a single sulphate ion. Do you know what the active compound is in that.  I just ensure there's 60-75mg Mg. Perhaps other components in my feed mix make up the difference in calcium to 3:1? Calcium requirements are apparently in the the range 150-180mg/L, but they seem to be doing fine at 2:1.

Edited April 22, 2023 by catweazle1

[Slippy One]

2 hours ago, catweazle1 said:

@Slippy One I don't know what mono mag is, I've not looked into it. Epsom is a single magnesium ion attached to a single sulphate ion. Do you know what the active compound is in that.  I just ensure there's 60-75mg Mg. Perhaps other components in my feed mix make up the difference in calcium to 3:1? Calcium requirements are apparently in the the range 150-180mg/L, but they seem to be doing fine at 2:1.

If plants are happy, that's all that matters..