Epsom salts causing salt deposits

[d4nk]

After I switched from cal mag to epsom salts my plants look great. Greener than ever, but I'm getting salt deposits on the top of the coco and at the drainage holes. i assume this is not how its supposed to be

 

[Sativa Dragon]

Epsom salt is magnesium sulfate,it has no calcium in it. Cal mag is a calcium and magnesium supplement and has no sulfur in it.Aside from that cal-mag also has a little nitrogen and iron as well.

Here is a good thread to read.

https://www.icmag.com/ic/showthread.php?t=192913

Peace SD

 

[indianajones]

if you are using tap water, it probably has calcium in it already, so calmag isn't
always necessary. you should check the ppm of your water out of the tap, yours
might be sufficient to go with just tap as a calcium source.

if you have salt buildup, a good flushing should take care of it. it could also be mycelial
growth from fungi, only way to tell is to look at it under magnification.

 

[watts]

use less? half to 1 gram per gallon should be good. You may only need it for a few applications.

 

[d4nk]

Its salt for sure. I was using less than a half gram a gallon. I stopped using cal mag because I only needed magnesium. Plants were happy as could be though so I dont think less would help. And I think I was only using .3 gr a gal

 

[carson]

If the plants are happy, who cares?

 

[skullznroses]

True Carson!

The old adage if it aint broke... dont fix it. I spent months fighting an unknown leaf infection last summer.. spent money and time spraying my plants and wringing my hands. In the end it never affected harvest and I stressed out for no good reason.

 

[Snow Crash]

You have this coco medium, like a big sponge all full of +2 and +1 cations like Calcium, Magnesium, and Potassium. These elements are retained by the media but can be made available when replaced with other +2 or +1 cations. Like two +1 Potassium cations replacing one +2 Magnesium cation, or a +2 Calcium cation replacing a +2 Magnesium cation, and etc..

What's happening is the +2 cation Calcium retained in the coco fiber is being replaced by the now abundant +2 cation Magnesium. This knocked loose Calcium is available to precipitate with Sulfur, the pH and temperature will affect the amount of precipitate available. This is basically lime scale, the same stuff that builds up around the shower and clogs drip lines.

It's nothing to really worry about. The salts are totally unavailable to the plant but Sulfur could become scarce in flowering. This is why it's important to never really high/low a system or eliminate an element from your program. While the plant may no longer have any major need for calcium, the media still has it's requirements that you are neglecting. It may seem counter intuitive but the best thing to do is to bring back a little bit of that Cal-Mag to keep your chemistry balanced. Just 1ml/gallon will provide enough calcium to prevent it from leaching out completely. There's really nothing you can do about the salt, maybe drip clean or clearex or a fulvic acid to help chelate them - but the buildup is going to come back. That's sort of the thing with salts and fertilizers in hydroponic media, you need A LOT of runoff and a balanced solution at every feeding to never see any build up.

 

[GEMiNi GENETiCS]

If you need to give the plants mag .... Try foliar spraying the Epsom salt ..... It will make it available quickly and you won't send your ratios out of wack in the coco

But the above calcium scale sounds about right .... I've had it before in my hot mix for the Diesels which eat up cal mag and some would cake up at the drains

 

[Johnny Hash]

This is my 3rd grow, all with coco. I'm using my base nutes (GH lucas method) w/ a few additives... then I add about 6-7ml of CaliMagic per gal of RO water, with .5 ml or so of Drip Clean, plus an occasional pinch of epsom salts...and that's been a damn good recipe thus far. I'm going on week 5 in flower and things are boomin'! Not one nute def. the whole grow... just had a few Calcium spots showing up in early flower, so that's why I up'd the calimagic from 5ml/gal to 6-7ish/per gal. All leaves have returned to perfect looking

 

[nachoconqueso]

I used to use Epsom with heads formula and had salt buildup. I dropped the Epsom and just do 6micro/9bloom per gal and it is the best grow I've ever done. No salt buildup and much bigger yield. The plants were always green, but now they do insanely well in flower. I use tap water btw. Epsom might need to be added in RO, don't know.

 

[Cereals]

You have this coco medium, like a big sponge all full of +2 and +1 cations like Calcium, Magnesium, and Potassium. These elements are retained by the media but can be made available when replaced with other +2 or +1 cations. Like two +1 Potassium cations replacing one +2 Magnesium cation, or a +2 Calcium cation replacing a +2 Magnesium cation, and etc..

What's happening is the +2 cation Calcium retained in the coco fiber is being replaced by the now abundant +2 cation Magnesium. This knocked loose Calcium is available to precipitate with Sulfur, the pH and temperature will affect the amount of precipitate available. This is basically lime scale, the same stuff that builds up around the shower and clogs drip lines.

It's nothing to really worry about. The salts are totally unavailable to the plant but Sulfur could become scarce in flowering. This is why it's important to never really high/low a system or eliminate an element from your program. While the plant may no longer have any major need for calcium, the media still has it's requirements that you are neglecting. It may seem counter intuitive but the best thing to do is to bring back a little bit of that Cal-Mag to keep your chemistry balanced. Just 1ml/gallon will provide enough calcium to prevent it from leaching out completely. There's really nothing you can do about the salt, maybe drip clean or clearex or a fulvic acid to help chelate them - but the buildup is going to come back. That's sort of the thing with salts and fertilizers in hydroponic media, you need A LOT of runoff and a balanced solution at every feeding to never see any build up.

Brilliant post Snow Crash! Thanks