How does one calculate nutrients based on EC - PPM?

[breezy12]

Hi, general question for those experts out there.

My schedule says add growth nutes to your solution at a measure of 1.5 EC.

The EC of my water prior to nutes is 0.4.

Does this mean:

1) Add your nutes till your measure is 1.5; or

2) Add your nutes until your measure is 1.9 (a combined total).


In any event - I assume that your EC will go up from the addition of extra additives apart from your base nutrient (silicon, root stimulant, pH down etc). So if making your nutes do you also account for these in your addition exercise?
i.e Water at 0.4 plus additives at 0.4 plus base nutes at 1.5 = 1.9EC; or
Add everything to aim for 1.5 EC.

Sorry if this is a basic question but I cant find it addressed anywhere.

Also - the process of making a nutrient solution for Cocco- is this the correct method:
1) De-chlorinate the tap water (48 hours)
2) Add in this order:
a)Additives
b)Base nutes
c)pH modifier if necessary

How long can this solution sit in a dark closet for and still be used?

I look forward to being enlightened

Cheers,
Breezy

 

[MassMedMan]

I would assume take into account the EC beforehand. Just a guess, but when I run House and Garden I adjust and feed based on what I started with. Good luck.

 

[BuddroGreen]

If your tap water is already EC 0.4 = 200ppm (Hanna 0.5 scale), then you would add EC 1.1 = 550ppm of nutrient to make it EC 1.5 = 750ppm.

It all depends on the size of the plant(s) for how much nutrient strength you give. If the plants are small starting out in veg, I would use an EC of 0.5 - 0.6 = 250-300ppm, and each week slowly raise the EC/ppm, same goes for additives. Start out using about 1/4-1/2 of bottle directions and work your way up slowly.

Most silicon products (raise pH) want you to put in water first or cal/mag...then base nutrients...other additives like root stim, carbs, etc, then you pH your nutrient solution. Mixed up nutrient solution stored in a dark cool place probably would go for awhile, another grower on here mixed up his nutrients for his Mom to feed while he went on a five week vacation and it worked...I've never done it myself, but it sounds like it can be done for a while. I would make sure to check the nutrient solution after a couple of weeks before feeding to make sure nothing weird is going on before feeding.

 

[breezy12]

If your tap water is already EC 0.4 = 200ppm (Hanna 0.5 scale), then you would add EC 1.1 = 550ppm of nutrient to make it EC 1.5 = 750ppm.

It all depends on the size of the plant(s) for how much nutrient strength you give. If the plants are small starting out in veg, I would use an EC of 0.5 - 0.6 = 250-300ppm, and each week slowly raise the EC/ppm, same goes for additives. Start out using about 1/4-1/2 of bottle directions and work your way up slowly.

Most silicon products (raise pH) want you to put in water first or cal/mag...then base nutrients...other additives like root stim, carbs, etc, then you pH your nutrient solution. Mixed up nutrient solution stored in a dark cool place probably would go for awhile, another grower on here mixed up his nutrients for his Mom to feed while he went on a five week vacation and it worked...I've never done it myself, but it sounds like it can be done for a while. I would make sure to check the nutrient solution after a couple of weeks before feeding to make sure nothing weird is going on before feeding.

Thanks so much - unfortunately having some issues with my grow - but trying a small feed now

 

[Rifleman]

This might help also. I use only a ppm measurement, not ec. I find it easier. I check my beginning water ppm, add whatever I plan to. Check ppm again, subtract the beginning number ppm of my water and have a rough idea that the answer is how hot I'm am running my nutrients.

 

[breezy12]

This might help also. I use only a ppm measurement, not ec. I find it easier. I check my beginning water ppm, add whatever I plan to. Check ppm again, subtract the beginning number ppm of my water and have a rough idea that the answer is how hot I'm am running my nutrients.

Thanks rifleman - I thought that might be the rationale behind it! I will give that a go oh and thanks for the table!