Keeping it Complicated, Stupid: Coco Hempy, JR Peters nutes, noobishness

My friend Ernie is a new grower and having some trouble understanding pH, PPM, and the proper level of nutrients to use. Unfortunately, he's using nutes that don't seem to be too commonly used: JR Peters' 16-4-17. 1/4 teaspoon of it dissolved into a gallon of water (half the amount listed on the package as giving 100 PPM) was strong enough to burn the dickens out of the plants when they were 22 days from seed. (He thought 3rd full set of leaves was old enough to feed, and that 1/4 strength was safe, he turns out to have been wrong.) Watered only with pH'd water and a pinch of CalNit since then. Plants are now 34 days from seed.

So Ernie got a PPM meter today, and has a pH meter already. But nothing makes sense anymore.

Rain water tested at 0 PPM. pH was over 8.
Adding 1/4 teaspoon of the nutes to a gallon of rainwater shot that down to 4.3 or so and it ended up being 200 PPM instead of the 50 PPM it should have been.

Dumping half of that out and adding the pH'd, slightly CalNit'd water from yesterday to get it to 4.9 resulted in PPM over 300. That's at 1/8 strength based on the packaging for the nutes, with an arbitrary pinch of CalNit since he doesn't actually know how much of that to add. And he hasn't even started adding epsom salts for magnesium.

Reading around, it seems that 300 PPM is fine, but how on earth is he ever going to be able to give these plants more food if this small of a dose knocks the pH down so low?

His guess is to add pH Up or baking soda or something basic to keep it at an appropriate level, but he is a little alarmed by the oddly high PPM already, even before adding other things to the mix.

This is all too complicated for what should be a simple weed. Can anyone spot what Ernie is doing wrong?

Details:
1.5 gallon coco hempy bucket, 70-75% coco coir (rinsed several times with water pH'd to 5.0 or so before planting the rockwool cube), 25-30% coarse perlite fill, 100% perlite reservoir.
Seeds sprouted in pH'd rockwool cube 1/3/15, transplanted to bucket 1/5/15.
One Jack Herer, one Gold Leaf. Plants are small and recently topped but look fairly healthy other than the burned lower leaves from that last feeding.
Growing under LEDs in a grow tent.




help?

Your friend Ernie sounds like a really cool dude. I love your post lol. Tell Ernie to do this....

- Hide the PPM meter because it overly complicates things, and is not necessary at all.
- Get a gallon jug of the rainwater, and ph test it so it is neutral approx 6.0. Shake the gallon jug vigorously to get the water oxygenated!!
- Immediately water all the plants thoroughly until water is coming out the bottom of the containers.
- wait an hour, and water all the plants again with the water. This will flush your soil and now you have a good baseline to work with.
- Wait a day or so, lift up the containers. If they feel light and dry, it is time to water them with fert.

- Fill up the gallon jug with rainwater, and add one half of the prescribed dose of JR Peters fert. This way they won't burn again. JR already has CalNit so do *not* add it.

- Shake the jug vigorously and then ph test the water, and ph balance it to ~6.0
- Water all the plants thoroughly with this, make sure it is draining out the bottom of the containers.
- Wait a few days for them to get dry
- Fill the jug with rainwater only, and ph balance it to 6. Shake it. Water all the plants.

Rinse, Repeat, and Lather!

After a few repeats of this routine, you will see how green your leaves are. If they are pale green, then you can use 3/4 of the prescribed dose of JR Peters.

Tell Ernie I said hello! And keep us updated.

rain water shouldn't test that low? Check his meter is calibrated. My veggies get 1000 [email protected] untill flip, 300ppm would make them eat themselves. Tell him to not over water, check his meter, change from rain water, up his ppms and get his ph bang on. Feed every time he waters, continuously flushing is unnecessary and actually damaging. Depending on his coco most come pre washed and buffered, it would be better to pre charge with ph,d 1/4 strength to aid cationic exchange. Add a root stimulus.

P.s Are you Ernie ?

The JRPeters product he's using is a one part nutrient;
16-4-17=
16% nitrogen
4% phosphorus
17% potassium

Since it's apparently a complete hydroponic nutrient it likely already has calcium in it, in the form of calcium nitrate. A careful reading of the label should confirm this. So don't add any!

Calibrate your pH meter with real calibration solution, rainwater is unreliable and in fact the low EC of it is bad for the pH meter. Running near 6.0 is safe. Forget you ever heard of 'ppm' and use EC instead, for several good reasons it takes too long to discuss here. Coco likes to run as high as EC 1.7, but start around 1.0 for the tender young 'uns and increase as they grow and get more vigorous.

Since you're in coco, you do not want to flush with water ever if you can help it. Run the above EC every feeding- and add water at every feeding until about 1/4 of it runs out, as this helps keep the nutrients from building up over time. Very important to do this because nutrient buildup will trash your crop in mid bloom if you don't.

Mix plenty of nutrient water at once, it will keep for several days and larger quantities are easier to work with.

This should give you ample time to bone up on the finer points of coco strain to waste technique.

And above all, have fun!

Thank you all very very much for the help. PPM meter goes back where it came from, to maybe be replaced with an EC meter. Onward and upward!

reddan1981 said:

P.s Are you Ernie ?

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Of course not! I live in a state that's kinda-but-not-quite legal until July, and Ernie is in a state of legality. It's just happenstance that he has a setup very similar to mine, only he's got some plants in his and mine's empty until July 1st in compliance with my local laws.

HollyD said:

Thank you all very very much for the help. PPM meter goes back where it came from, to maybe be replaced with an EC meter. Onward and upward!


Of course not! I live in a state that's kinda-but-not-quite legal until July, and Ernie is in a state of legality. It's just happenstance that he has a setup very similar to mine, only he's got some plants in his and mine's empty until July 1st in compliance with my local laws.

Click to expand...

I'm from uk (sad face). Good luck hun..

Whats up? Here's how I create my concoction...

Get your gallon jug.. throw in just a little less than half teaspoon of the hydrofeed and a little less than a teaspoon of Epsom salt.. Fill with luke/tepid warm water... Shake shake shake

Water til runoff


My plants really seem to love my tap water.. I never would have guessed it but its true.. I tried the rainwater when I first started and it worked well til something happened with my pH... Unless you have well water, I would consider just using your tap.. Best of luck player!

That's even easier! They look like they can use some magnesium, and I have a big bag of epsom salts. Thank you!

Edit: Holy cow, that totally changed everything, it's perfect. 6.0 on the nose. Blowincherrypie, you rock.

It turns out Ernie's kind of a doofus. So the poor plants have been getting weaker and weaker feedings and yet nothing improved. It turns out that what he thought was nute burn was actually light burn from being too close to the LEDs. So. Live and learn. Lights are adjusted, feeding is adjusted, and here's hoping the girls bounce back from their unhappy childhood and blossom into lovely young ladies.

Just a quick followup-- yes, the problem was absolutely light burn, not nute burn. The poor little sprouties were getting burned and starved at the same time, no wonder they were sad and stunted. Lights are a few feet away now, they're getting food as specified by blowincherrypie above, and they are lush and green and happy now. Stay tuned for the inevitable questions when Ernie flips them to 12/12 and flowering nutes in a week or so!