[kushedy]

I know there are a ton of threads on Jacks & using various ratios but I wanted to start one that related to growing with Jacks & what have has now been classed as high powered LED's, i.e. cobs (CXB's,Vero's etc), Samsung strips, quantum’s etc.

As many if you who have made the jump to LED are aware there seems to be a greater demand for Calcium or Magnesium or both when growing under LED.

I'm just curious to see if any of you have roughly nailed the Jacks, Calcinit & Epsom ratio's for growing under LED? Or has anyone found that the 321 approach has worked well under LED?

[starke]

I am running Jacks/Calnit at 1:.67 without the need for added calcium or magnesium. Growing under an URSA Optilux COB setup at 640 actual watts and using 3 gallon perlite/vermiculite Hempy Buckets. PPM has ranged between 600 and 800 at .5 scale.
Strains have been Super Lemon Haze, Hawaiian Snow, Juan Herer, Liberty Haze and Skywalker Kush. None have exhibited any deficiencies thus far.

[beta]

I ran Jack's 3-2-1 under 315W CDM and it worked great.

[kushedy]

That's interesting considering people using other types of nutrients are having to supplement with calmag. I'll be honest I haven't tried yet but am going to be trying this shortly.
I guess there must be enough calcium & mag in those ratios.
cheers all

[mcnasty]

I had to change to 3-2-2.5 with my cobs
Thats jacks-cal/nit-mag/sul Until I got my temps up. Make sure your temps are about 82-84 in flower. After that I didn't need to add any mag. Now I switched over to greenleaf nutrients megacrop though. Not to be an infomercial or anything but its cheaper, and my plants seem to like it better. I mean its really a better mix if you look at the ingredients.

In any case though both work perfectly as long as you keep those temps up

[kushedy]

Cheers mcnasty. I have tube heaters in each grow tent at the mo. Gone are the days of fighting to keep temps down! Gone full swing. Now fighting to get temps up. Have heard a lot about megacrop. Sounds interesting but I am a little put of by their website. State's all the things incorporated in it, like early & late stage bloom booster. How exactly do you include a early & late stage bloom booster into a one part fertilizer? early & late stage bloom boosters typically have different npk profiles.
I know it does include a lot of additives which most would normally buy separately which is great in general but why say it includes multiple boosters when it is technically one npk profile from seed to harvest. Makes me not overly trust them. Could be the best thing since sliced bread for all I know but stuff like th st gets my back up a bit.

[Jeeyah]

I measure by volume. My tap water is 140PPM.

In a 44 gallon reservoir I will mix

4 Tbsp Jacks Hydro
4 Tbsp epsom salt
4 Tbsp Calcium Nitrate

That’s about 780 PPM or so. I usually have to add a little bit of PH down. But, right now I don’t. The tap water fluctuates.

I’m in week 5 right now so I added

5 Tbsp Jacks
4 Tbsp epsom salt
4 Tbsp Calcium Nitrate

That’s about 830 PPM

This is in drip fed coco with COB lights.

[kushedy]

Interesting so you're going with equal amounts of each most of the way through & then dropping off the Mag & Caclium a tad towards the end.
Is that a combination you have worked up to from trial & error? or for other reasons?

[Jeeyah]

Yes. I’ve been working with Jacks for about a year now. The directions say to use in equal amounts by volume. I just had to figure out the strength and amount of Epsom salts added.

If I even reduce the amount of Epsom salts added I see magnesium deficiencies. I usually just use it in equal parts by volume. It’s about 3/8 tsp of each per gallon.

[kushedy]

Thanks Jeeyah. Good to know. Right now I'm testing a Solufeed recipe someone from another forum posted. So far so good. Once I have finished this run I'm going to give Jacks ago & see how that compares.