Coco tapwater question -Cal/Mag

[ThisOneGuy]

My first grow in a while, and my first grow with coco. Plan on using 70/30 pre- buffered coco.

Anyway, my tap water is about 200ppm.
Should I still use Cal/Mag, or maybe just Epson salt, assuming that alot of that 200ppm is calcium? If so, how much Cal/Mag, or just Epson salt if just that, would you recommend?

Or, is 200ppm nothing, and I can just add Cal/Mag as if ppm was 0 and be fine?¹

Also, even though coco says buffered, should I go ahead and buffer it again?

Thanks in advance.

 

[DR.PNW]

If this was dirt:
Recommended to still use a cal/mag supplement at that base ppm.
You could use half the recommended dose and see if it is enough for your plants, but you can more than likely feed them full strength.

Coco is a different beast all together and the rules of dirt do not apply.
200ppm base is negligible for coco.

Essential differences and procedures:
-Buffer and rinse
-Always feed with CaMg [as in; every watering]
-Feed every watering
-Feed half strength always [500ppm in, 500ppm out]
-30-40% runoff

Do some deep research before growing in coco.

 

[LexLuthor]

You need extra Cal/Mag when growing in coco, but some nutrient lines, like Canna Coco A/B, have enough Cal/Mag and you only use extra if using RO water.

So it depends on the nutrient line you are using.

If you are using a high quality coco that says pre-buffered and is known for being used straight out the bag, with no problems, I would not buffer it. This is because if you don't do it right you will actually make it worse.