Hello everybody,
I grow three plants in a 85 liter hydroponic system and currently a General Hydroponics guy looking at other nutrient lines. Wondering if someone here has a seedling, veg and bloom feed rate for Jacks products. Your Rez volume, and product added in grams.
2 Likes
It’s about 1 gram part A, 0.6 grams part B, and 0.3 grams Epsom per liter
2 Likes
Thank you sir.
1 Like
morning Harold… is there a reason you want to leave GH nutrients?
Couple of years ago I bought a ton of GH products at a going out of business sale, so no, I wouldn’t be changing anytime soon. The reason for the Jacks information is to compare my GH nutrient solutions N P K ratios to another product line. I created a PPM calculator for Jacks products and will post soon. My in-laws are visiting from out of state and are staying for a week, and not three days. No, not a bad thing. he loves to do projects around the house and I plan on keeping him busy 
1 Like
1 Like
I compiled my chart information from J.R. Peters Product Data Sheets, material Safety Data Sheets (mSDS) found on their web-site. I noticed on the mSDS in Section 9- Chemical and Material properties, the relative density is stated as 55 - 75lbs/ft^3 which is ~30% change in product weight. When I emailed them about the RD delta, their reply was to apply their products by weight, and not by volume and it is not a problem which I totally agree. I converted 65lbs/ft^3 to metric 1.0412 for my PPM calculator in the next chart.
I just looked at a bag of epsom salt at the local hydroponics store and used the info on the label for this table. I could always use GH CalMag as well. What I don’t see is any humic acid, or SiO2 in any of these listed products, so that would have to be added here as well.
J.R Peters responded to my emails within a day which is always a plus.
I created Table II from the data in Table I and the product I added in grams for a 85L nutrient solution. I calculated the PPM for each product in the right column and list the weight in grams for each element in the bottom row. Thanks @bobbydigital for the nutrient feed rate. I tweaked it a little to match my GH solution Which I will post tomorrow.
Output page for Jacks nutrients. I did not use Jacks; I just calculated the PPMs and comparing it to a GH solution I’m currently using. I use well water which has a high starting EC, so measure it before adding nutrients EC(s). After mixing all nutrients, I record the final EC as EC(m). In accordance with Bergman’s Grow Bible, I subtract the starting EC from the final EC and record it as EC(diff) which I use to calculate all applicable PPM scale factors listed. So, for an 85L nutrient solution, I calculated Jacks solution in Table II at 408 PPM and measured it as 420 PMM. Not bad correlation!
Here is my Table I, General Hydroponics product list with information found on their website. Yes, I am a member of AA, that’s Additives Anonymous… I’m down to about half the products on the list.
My GH Table II from my current grow. I tweaked the Jacks solution to match the PPMs in this solution to compare nutrient content.
My GH Table III from my current grow. The calculated PPM from Table II was 409 PPM, and measured PPM is 420 PPMs!
Jack’s, General Hydroponics nutrient solution comparison. The Jacks is missing Humic, Fulvic acid, and SiO2, but all other nutrient content by weight is very close. The Jacks recipe cost $0.43, and the General Hydroponics cost $4.15 which is probably the main driver why people are switching. I’ve had such great success through the years it would be hard to change at my age.