[iruleyou1]

I am about to start my first grow and will be using Jacks 321 in a 5 Gallon DWC System. I have been reading years of posts and have a few questions I can't seem to find the answer to. I will be using tap water that has around 130 ppm taken with the meter I purchased. Most of the information I have found says to use a PPM/EC meter for a final reading of around 600 with RO water.

If using tap water with a PPM of 130 what should my readings be (would it be something like 730)?

I see the recommendation of using a PPM meter so you don't have to measure however I don't see the numbers I should have after the addition of each ingredient and just the final PPM readings. Wouldn't I need to know the reading after each ingredient to truly not have to measure?

What is the correct way to top off? I am finding mixed information ranging from just add water as needed and flush everything out after 3 weeks to never flush topping off with water and nutrients (test ppm).

Sorry if these are silly questions.

[Speed of green]

i use jacks and tap water.

just to start you off in the right direction, different brands of PPM/e.c meters come in different conversion scales. 500 & 700 are the most common, although i used to have one @ 650.

i recommend a google search to the manufacturer to be sure you know what scale your meter reads in.

This generally isnt an issue, but for example if your meter reads in 700 scale and you mix your nutrients to 600ppm the solution will be 410ppm on 500 scale. this will result in weird deficiencies that are hard to figure out because you think you are feeding them the proper amount when in reality you are underfeeding.

The solution to all this is to know what scale your meter reads in PPM or get a meter that reads in e.c

Whats e.c? electrical conductivity, basically the more stuff in the water the more conductive it is.

e.c is like Fahrenheit ppm is like celcius, both can give you an accurate reading if you know how to use the tool.

when posting online and discussing nutrients or water with friends i always state my readings in e.c because unlike PPM there can be no confusion about what scale im referencing.

Ill finish the rest of this post referencing PPM @ .5 or 500 scale (this is the proper scale to mix jacks at)

To answer your question I mix my jacks on top of the water, so if my tap is 300PPM and i want to add 600PPM of solution my final reading will be 900PPM.

you have to mix the jacks epsom and calnit in this specific order, if you dont youre going to have problems. the issue with this is that once youve added all three ingredients if you havent hit your target of 600ppm then you get to scrap that reservoir and start over. adding jacks after the calcium nitrate will cause problems.

to simplify this process i mix my nutrients slightly different than most folks, this results in some slight waste the first few batches but you will never have to dump out a reservoir because its too weak or strong of a solution.

to start you will want to weigh up your nutrients in the correct ratio

lets say your making 4 gallons of solution

15g jacks
5g magnesium sulphate (epsom)
10g calcnit

So you take bucket A and put 4 gallons of tap water in it.

you take bucket B and put 1/2 gallon of tap water in it

you then add 15g jacks to bucket B
mix for a couple minutes

add the 5g epsom to bucket B
mix for a couple minutes

add the 15g calcnit to bucket B
mix for a couple minutes

then you pour the contents of bucket B slowly into bucket A until you reach the desired PPM

discard any remaining contents of bucket B.



As far as topping off goes you need to monitor the DWC system, sice you never change the ratio of jacks/epsom/calcnit depending on the stage of growth you are in the plant will uptake different nutrients.

since it is only selecting certain nutrients and leaving others behind these left behind nutrients can cause the PPM to steadily climb. monitoring the PPM and doing res changes at around 1000PPM should keep you safe from burning the plants.

if you are just running a single plant site i would recommend changing the res every time so that it will always be right and its not that much work vs 99 plants

good luck hopefully all of this makes sense, let me know if you want clarification on anything.

hope i didnt confuse you haha.

[iruleyou1]

You didn't confuse me at all. Thank you so much as that was the answer I was looking for and what I ended up doing. Since the ppm of my water was 150 I aimed for a final number of 750. I had to start before receiving an answer but you confirmed my logic and make me feel better that I did it right.

Also good advice on the ECC meter. I validated the scale mine was running on before starting.

I'm running 6 plants in 5 gallon DWC buckets so changing it out can take a little time. I'm going to go with the premixing advice next time I do this.

I like the 6 separate buckets because as a noob I can try different things out in each bucket. Also a problem is contained to a single bucket. I have a feeling with experience I will change to something more simple with a common reservoir.

Thanks again!!

[Douglas.Curtis]

No idea what your pH changes will be like with your specific tap water. Speed of green is right on with their advice regarding meters and nutrient strength.

I recommend getting an r/o filter for home use. pH is super predictable, hydro results are super predictable, the cannabis is definitely cleaner, it's awesome water for drinking/cooking with AND, when you move to a new water supply you won't have to "learn hydro" all over again with your new tap water supply.

DWC is stupid simple, when you use the Lucas mix and res management methods. I've watched people have problems for almost 2 decades trying it other ways.

[iruleyou1]

I may get an RO filter next time but my PH has only risen slightly over the entire week.. I may be one of the lucky ones. I've spent so much on my first grow to get in a 5x5 setup. I'm at the point I want to see how a grow goes and make slight changes to see the results. My issue with RO water is the wasted water and I would have to run the waste outside in the winter. I don't want all the extra going down my septic system.

The big thing I learned is a 4x4 tent would have been a better starter tent. When you go 5x5 you are doing more research as a noob and have to build custom parts such as lighting. The bonus has been it forced me to learn far more.

At this point I am a few weeks into the grow and everything is looking nice. Next time I may add drip rings for the first few weeks and turn them off once the roots reach the water.

[Douglas.Curtis]

Get a 1:1 output filter and a waste storage tank. A pump and hose will allow you to drain the tank when it gets full. I recommend washing your car (with an r/o rinse to prevent spotting), watering your lawn or garden or any other 'water' activity.

It's not 'waste' unless you actually waste it.

[iruleyou1]

That's a really good idea. If my first grow doesn't go well I will try that. My logic was my ppms weren't too bad and I may have decent water and never know unless I try. I don't want to do the extra step and find out I never needed to.

[Douglas.Curtis]

Originally Posted by iruleyou1

That's a really good idea. If my first grow doesn't go well I will try that. My logic was my ppms weren't too bad and I may have decent water and never know unless I try. I don't want to do the extra step and find out I never needed to.

Ty. One of the many up-sides to using r/o. After moving several states and various water supplies, I can still visually judge how much pH up I need and toss it in and I'll rarely need to adjust it. The amount of pH up for each gallon of water hasn't changed in 15 years of using r/o and the same basic nute mix, regardless of water supplies. Once it goes through my r/o machine, all the variables for pH are pretty much eliminated.

[Speed of green]

you could also send a water sample to JR peters directly and they will consult you on how compatible your supply is with their product. I think it runs around $40

Like doug said though R/o is the peanut butter to jacks jelly, Ph is on autopilot once youve mixed a few res's.

[iruleyou1]

Update. I have switched to RO water at time of flowering like the suggestions and for the life of me I can't keep my PPMs and PH stable anymore. I will say my plants definitely look healthier since the switch to RO but it may have something to do with the 12/12 flip at the same time. Instead of mixing by PPM I am actually mixing by weight. I am hitting my target PPM exactly (within 10 every time) and it is way, way faster if you know the volume of water. I have not gone over or under doing it this way and I don't have to worry as much if it is fully dissolved. Doing it by PPM I have had the reading change after 10 minutes. The PPM meter is still great cause I can double check.

I came up with my weights using 3.6 grams, 2.4g jacks at 1050PPM from another post

600 ppm
jacks 360 ppm, calnit 240 ppm 240/360=.67
jacks 2.057g, calnit 1.371g

750 ppm
jacks 450 ppm, calnit 300 ppm 300/450=.67
jacks 750 = jacks 2.571g, calnit 1.714g

850 ppm
jacks 850 = jacks 2.914g, calnit 1.943g

Depending on the gallons of water I just multiply the above numbers using a scale accurate to a .01. I validated the initial numbers using a milligram .001 scale. It is so accurate one of the little blue calnit crystal changes the reading.

Now my question. I have been following the rule if PH rises and PPMs fall up the strength of the nutes until things equal out. I keep increasing strength so I am now running 850ppm. The next day my PH changed from 5.5 to 6.2 and PPMs dropped from 850 to 700. Is this normal running jacks? The plants are growing like crazy though.