Homemade/DIY CalMag?

[mysticriver]

Im nearly running out of CalMag -

Could I use Canna Mono calcium to take RO water to 300ppm/0.3ec

Then add Epsom salts (Mg) at 100ppm to take it to 0.4ec

0.4 is what everyone says to add calmag to RO and take the ec up to

And the Ca:Mg ideal 3:1 ratio is achieved 

Can I get by with homemade calmag in this way, or am I missing something?

 

 

mysticriver 

 

[mysticriver]

Tagging @Oldbear for an opinion

 

 

mysticriver 

[Oldbear]

12 minutes ago, mysticriver said:

Tagging @Oldbear for an opinion

 

 

mysticriver 

Hi mate, 

 

I'll be honest I don't know how to convert ec to PPM. The logic of your conclusion appears sound, I'm just concerned about the amounts. 300ppm for 0.3 seems a lot but I'm a mud guy. Perhaps @zen-ken or @GSZZ can help here

[GSZZ]

Just now, Oldbear said:

300ppm for 0.3 seems a lot

 

Ita double that 50ppm = 0.1 ec 

[Oldbear]

@mysticriver

 

I've done some basic calcs for you :

At 50ppm=0.1ec 

Using 0 TDS RO water you'd need the following for a base ec of 0.3

 

105ppm Ca = 0.88ml/ ltr Canna Cal @12%

 

35ppm mg = 0.5ml/ ltr canna mg @7%

 

[mysticriver]

23 hours ago, GSZZ said:

ita double that

The conductivity pen I use is us/cm, which reads 100 units for every 0.1ec of solution. So it would read 800 for 0.8ec, 1700 for 1.7ec etc.

Ive just grabbed this from google about how to convert the reading.

How do you convert uS cm to ppm?

*Parts per million (ppm) are considered the same as milligrams per litre (mg/L). Simply times (x) EC (μS/cm) by . 55 to get an approximate ppm equivalent.

I have a bluelab truncheon so I can measure ec. But ill have to get my head around the figures - so its either all that number, or half...

It seems ive got ppm & tds mixed up with us/cm

19 hours ago, Oldbear said:

0.5ml/ ltr canna mg

I would do the last bit with Epsom salts as thats what I have in stock. Should be simple enough. 

Ive bitten the bullet and ordered some more CalMag...

But just to clarify - do I take the reading to 300 on the pen/0.3 on the truncheon, with calcium, and thats my 0.3ec?, then add the Mg.

It probably doesn't need as much as that, as ive noticed CalMag contains a little iron and some nitrogen salts, which im wondering if they'd add to the ec. They probably do.

Thanks for both your input.

 

 

mysticriver 

Edited December 2, 2021 by mysticriver