is it true you can use yougart ?

My stems are rather red heard they mey need cal and mag also heard u can use yogart in the water for cal does this work ? And what can u use for mag and zinc ?

Yogurt may work if your in a soil application but I have never used it myself to answer that. You can use Epsom salt for mg. For zinc you can use zinc sulfate, or a chelated zinc source like zinc EDTA, DTPA, EDDHA, or an amino acid type zinc.

Get some K not mag red steams

If you post a picture than people can give you more solid advice. It could be from N, P, K, Mg, or genetics.

If your to cheap to buy some Cal/Mag you can use "Tums" it has Cal/Mag.
IMO- I wouldn't use Yogurt

If you have a local hydro shop and your nice to them they prol have boxes of free nutes from the companies for testers. Ask and you never know... may get hooked up. But I'm looking at a bottle of Cali magic cal mg and it's not more than 15 bucks and you know it'll work.

Evry ery customer we had yesterday got some free shit, we were doing starter boxes of nectar of the gods and kyle kushmans og tea pure and web root. Which by the way are two great products.