Lucas formula questions - Need help understanding

[lexort420]

Ok so I been doing as much reading on this as i possibly can but there are some thing i need clarified as i couldn't find anything definitive regarding my questions so i seek the wisdom of the great community. I realize since im growing with cfls that i would want 5ml of micro and 10ml of bloom now here comes my first question am i to understand that i give only 5ml of micro and 10ml of bloom through the entire grow or does it scale up in ratio? Now I read that when growing in soiless you would want to add either 1tsp of calmag or 1 gram of epsom salts now i wanna go the epsom salt route as i have it on hand and can't justify spending that much money on calmag supplements so my second question is would it still be a gram of epsom salt since i would be doing the 5ml of micro and 10ml of bloom cause im growing with cfls or would i need to reduce that down too and if so by how much? I like the lucas formula from the little understanding i seem to have of it but i am struggling to fully wrap my head around it and with everything ive read on the topic seems to leave something out or so it seems to me thus leading to my confusion. Any help with this would be much appreciated maybe im over thinking this but i wanna be sure i understand before i try it out. Thanks in advance

 

[iwltfum]

1tsp of cal-mag is not equal to any amount of epsom salts. The epsom salts are just sulfur and magnesium. Any cal-mag will with have both calcium and magnesium in it. They will also be in a nitrate form so cal-mag generally has a nitrogen content too. So if you need both calcium and magnesium, then epsom salts won't cut it.

Also, there are different brands and concentrations of cal-mag. 1tsp of cal-mag is kind of a vague thing to say because with some brands, you might only need 1ml, or 2-3ml, and some brands where you need 10-15ml. Go with the directions on the bottle if you use cal-mag. There are powdered cal-mag's too that you either need to dilute or use in tenths of grams per gallon.

 

[lexort420]

Well i do realize that there is a difference between calmag and epsom salts but i believe my nutes have sufficient calcium but is lacking in mag so as initially stated i am going the epsom salt route. Lucas formula for coco is is essentially what I am talking about when i said calmag or epsom salt and im growing in a soil less mix and am always running into mag deficiency so i know I should add some. The lucas formula would be a 5-10-9 npk ratio containing 5% calcium and 3% magnesium before adding any epsom salt. Im gonna try adding 1/4tsp of Epsom salt to the formula since im running cfls i suppose it only makes sense to not add a gram since 1tsp equals 493mg of Epsom salt so to me that sounds like an amount meant for hps and the like. So to put simple 5ml micro 10ml bloom 1ml epsom salt. Any thoughts?

 

[iwltfum]

Ah. Gotcha!

I think, if you're running in to mag deficiencies, you should think about adding more than just a 1/4 tsp. That's only 1/8th of the recommended amount.

 

[lexort420]

Well and i thought it was low too but was unsure since there is 3% magnesium in 10ml of bloom so i didn't want to over due the Epsom salts thus why was asking lol

 

[iwltfum]

Well epsom salts is about 10% magnesium so your probably right to start with less.

 

[lexort420]

I suppose i can see how it goes and adjust accordingly gonna give it on the next watering see how it goes. Thanks iwltfum!