The Jack's 15-6-17 thread

Snowback

Well-Known Member
Well...it's not going to be much of a thread at this point, but there is almost nothing in any of the forums about this particular blend, so I wanted to get the ball rolling for future users/readers with a couple comments which I will follow up on in the future (if my herb-addled mind is capable of remembering to do so).

I have experience only with two blends from the Jack's world. The first is the ever popular 3-2-1 program which, for those who don't know, is the combination of Jack's 5-12-26 blend, calcium nitrate, and magnesium sulfate in a 3-2-1 ratio, respectively. Personally, I have had slightly better results with Mega Crop's "rip-off" of this blend. The Mega Crop has a different chelation system, some minor secondary and micro differences, and the addition of .15% silicon dioxide. For me at least, it works a bit better even though it is way more "dirty". Jack's is beautiful and "clean" in your res.

But now to the purpose of the thread: the 15-6-17 blend. They claim that it's for clones but that's a gimmick. It's very similar to their other blends and they want you to buy it in addition to their other stuff. No problem with that. It's a company and it wants to make money.

I had instant love for this blend. It is perhaps the most rapidly soluble blend from any brand that I have used since the old Plant-Prod days (original Plant-Prod was as hot and unforgiving of error as liquid chicken sh*t, but it did dissolve quickly and easily). In my tap water, which is very low EC and at a PH of about 6.9, the 15-6-17 dissolves even faster than magnesium sulfate, which as many of you know dissolves extremely fast in most municipal tap water. I would say that it takes about 5 seconds to fully dissolve while being stirred. That is impressive!

With an interesting ratio of [2.5-1-2.8], it is almost a complete blend, lacking only sulfur. I can't speak for Jack's Classic line, but these newer Jack's blends are always missing at least one element; usually either calcium or sulfur. This is probably in order to keep them from reacting while in powder form while maintaining rapid solubility. One parts that contain calcium, phosphorous, and sulfur together usually have to "encase" the calcium inside something the "melts off" when added to water, which can slow down how fast the blend dissolves. "Maxi-bloom", for example, takes forever to dissolve completely in my water. In fact, I hate using it because of that property. But it is a complete one part. Not a big deal if a blend is missing sulfur. Magnesium sulfate is cheap and is also a great thing to add to a mix, regardless.

The recommended amount 15-6-17 needed to achieve 100 ppm of nitrogen is only .66ml/liter. With this as their recommended strength, a relatively small amount of this stuff will last a long time for a rec grower such as myself. An extremely long time! This comes out to about .85EC including my personal preference amount of added magnesium sulfate, so the grower has some wiggle room to experiment with additives if desired. This is not necessary though, other than adding a source of sulfur.

The PH of a fully mixed solution in my water comes out to a wonderful 6.1. No further adjustment needed, and it does not drift, at least over the course of a couple days (I am DTW so I don't keep it for longer). Interestingly, a half strength solution has almost the same PH as the full strength, which causes me to speculate on what sort of buffers they may be putting into this stuff. Happy!

Some blends of Jack's are known for, shall we say, a very generous amount of blue dye. I have read the complaints of res water that looks like toilet bowl cleaner and blue stains all over the inside of peoples' reservoirs, on their pumps, and just about anywhere else that the water regularly comes into contact with. This blend has only a very small amount. The water becomes a very pale hue of aquamarine. If you scoop up a little glass of it, the water appears to be clear. For people who use colored drops to test their PH, this is an important feature. That said, I would still prefer no dye at all.

Nitrogen source is somewhat of a topic of debate (what around here isn't a topic of debate?) but I personally prefer some ammoniacal nitrogen in my mix. This is after loving Dynagro Foliage Pro, which is rather high in it, for several years. That Dyna grows 'em fast! Jack's 15-6-17 has about 20% percent ammonical and 80% nitrate. This was one of my original reasons for wanting to try this blend. For those that think this is too high of a value, you do you and we can all be happy...

I would prefer a little more calcium in this blend but I believe that what is here should be enough. If it is not, I will include those observations in a future post.

As far as the effect on the plants, it's still fairly early for me to give much in the way of feedback, but I can say that they are very happy so far. In fact, I might have to eventually take the dose higher than Jack's recommendation, but time will tell. I might also do an early flower phosphorous boost as well. That's undecided as of yet however and depends on my reading of the plants at the time.

As stated previously, I will try to remember to return here with future updates, as I plan to do a start to finish with this stuff.

Thanks for reading.

Here is a pic of the label:15-6-17 .jpg
 

Snowback

Well-Known Member
Tint, it's nice of you to check in. No lie, I was wondering what Tint Eastwood would think of the ratios when I wrote the original post. Thanks for the additional info.
 

Snowback

Well-Known Member
It worked pretty well; start to finish.
I did 4 testers. I will post pics as they finish. The earliest of the 4 is done now.

So the following routine was used for this test: Jack's 15-6-17 + 1.5 grams/gallon magnesium sulfate (for the missing sulfur) mixed to just a little under 1.2 EC. During the first 3 weeks of flowering, GH Liquid Koolbloom at .5ml/liter was added for a little phosphorus kick. The EC was about 1.4 during that time. I eased off for the last couple of weeks down to less than .4 EC. On 1 of the 4 plants, calcium deficiency developed after I reduced the amount. Didn't matter at that point.

Strain is "Bad Bird", which is: [Falcon 9(Exotic Genetix) x Purple Badlands(Greenpoint Seeds)]
Burn is clean and smooth.

I would use this mix from Jack's again any time.IMG_0038 - Copy.jpgIMG_0041 - Copy.jpg
 

Snowback

Well-Known Member
15-6-17 worked great for me, but remember to use a little magnesium sulfate or calcium sulfate in order to make up for the missing sulfur. I used it at about 0.8 - 1.0 for young plants.
 

dwc420letsgo

Well-Known Member
that looks so fucking dank.. i just ordered jacks 321 and i am going to a/b some clones between the 321 schedule and your formula too see what's up
 

stiffnuts12

Well-Known Member
Looking good snowback. I'm using the
jacks 12-4-16 with my rdwc seems to do Ok. Would like to see this page grow and maybe get some help to tune her in
 

Snowback

Well-Known Member
I use the Megacrop 2 part and I really love it. I've posted about it in some other threads. So many good ferts out there worth trying.
 

Splash Gordon

Active Member
Does anyone have experience with Maxigrow/bloom line? I’ve been getting some good results with it but considering jacks, mega crop, nectar of gods, and Athena. I’ve used fox farm nutes and find maxi line easier w/ better results. Growing in ffof with 25% perlite
 

Snowback

Well-Known Member
I used it for a while but I had solubility issues with it. There were always some hard chunks of crystal that would not dissolve. It seemed to work okay but I was not willing to run it through my pump.
 

stiffnuts12

Well-Known Member
I used it for a while but I had solubility issues with it. There were always some hard chunks of crystal that would not dissolve. It seemed to work okay but I was not willing to run it through my pump.
Where do you like your ppm/ec in hydro?
 

Snowback

Well-Known Member
I haven't done hydro for many years so I don't remember but I always found that the plants could handle a stronger solution and at a more acidic PH. This was for top feed rockwool and flood and drain rockwool with lava rock.
 

Snowback

Well-Known Member
On the subject of the OP, my Jack's 15-6-17 turned into complete mushy sludge in my main use container, which seals well but it not air-tight. So remember friends, be mindful of any of your powders that contain ammonium nitrate. It's very hygroscopic. My properly sealed portion is still okay but in my main container it only lasted just over a year. On the positive side, the sludge was useful as a light mix for large hose waterings of my outdoor veggie garden. At least it didn't go to waste.
 
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