Looks like a CalMag issue . . .

HydroDawg421

Well-Known Member
Green Crack & Gush Mints strain using Air-Pots in hydroton. The plants look otherwise very healthy. I water for 10 minutes every 4 hours.

This presents as a CalMag problem (I think) but I add 30-50ml of CalMag + Iron to a 12-gallon reservoir when I change my nutes every 5-7 days. That being said I find it hard to imagine this is a CalMag deficiency. EC of 2.4 with 1100/1500 ppm's (500/700 scale). When I add that much CalMag, it spikes my EC to about 2.7 and I have to dilute it back down to 2.4. I also add 1 cup of hypochlorous acid when I mix a fresh batch of nutes. It's a food-safe disinfectant that doesn't change EC/ppm's or affect the Ph. It's essentially bleach without the bleach!

I'm growing in a 4x4 flood/drain using top feed that drains back to the reservoir. Using Jack's 321. The room is temp-controlled (78 degrees), temp at the plant tops is 80 degrees, and the lights are approx 18" above the tops, 60%-ish RH, running 1250ppm CO2. Water is chilled to 65 degrees. Ph is always between 5.8 - 6.2. VPD is .75 -1.0 typically.

I have 1 LED NextLight Mega Pro. I just raised it from 12" to 18". I guess this could be light burn?

I also have nothing in my well water. It comes back at .09 EC. It's literally just water
;)


IMG_5732.JPGIMG_5731.JPGtop-drip-hydroponic-system-diagram.jpg
 

HydroDawg421

Well-Known Member
Jack's 321 already has calcium and magnesium, why are you adding more?

Because I previously had CalMag issues a couple grow back and Jack's told me to.

What are you thinking? If they need it, they'll take it. If not, they won't. Are you suggesting too much CalMag?
 

weedstoner420

Well-Known Member
Because I previously had CalMag issues a couple grow back and Jack's told me to.

What are you thinking? If they need it, they'll take it. If not, they won't. Are you suggesting too much CalMag?
I'm not very good at identifying deficiencies, but to me that doesn't really look like either a calcium or magnesium deficiency. It's also hard to tell from just one leaf that isn't attached to the plant anymore.

I have noticed a lot of growers on here using Cal-mag in addition to nutrients that already contain calcium and magnesium, having weird issues with their plants that are hard to pin down. And there are also lots of growers out there using Jack's 321 with RO water, having no issues at all. So I guess I am suggesting too much Cal-mag. You could try dropping it and seeing how the plants respond...?
 

curious2garden

Well-Known Mod
Staff member
Because I previously had CalMag issues a couple grow back and Jack's told me to.

What are you thinking? If they need it, they'll take it. If not, they won't. Are you suggesting too much CalMag?
Another possibility is you could be locking out related to too much Ca, binding preferentially.

I run my swimming pool on a hypochlorous loop with a chlorine generator. In my hydro reservoir however I use Pool Shock :) which is less expensive then a salt cell, longer exposure times and chloride is a necessary micronutrient.

To be more helpful pictures of the entire plant would help.
 

HydroDawg421

Well-Known Member
Another possibility is you could be locking out related to too much Ca, binding preferentially.

I run my swimming pool on a hypochlorous loop with a chlorine generator. In my hydro reservoir however I use Pool Shock :) which is less expensive then a salt cell, longer exposure times and chloride is a necessary micronutrient.

To be more helpful pictures of the entire plant would help.
I'm going to do a reservoir change this morning and just run straight water for a few hours to flush. Then later this afternoon/evning, I'll use the standard Jacks 321 recipe without the CalMag to see what happens. I'll attach some pics taken a few minutes ago.

I don't have a pool and know nothing about them. Tell me about 'pool shock'.

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curious2garden

Well-Known Mod
Staff member
I'm going to do a reservoir change this morning and just run straight water for a few hours to flush. Then later this afternoon/evning, I'll use the standard Jacks 321 recipe without the CalMag to see what happens. I'll attach some pics taken a few minutes ago.

I don't have a pool and know nothing about them. Tell me about 'pool shock'.

View attachment 5281027View attachment 5281028View attachment 5281029View attachment 5281030View attachment 5281031View attachment 5281032View attachment 5281033

Start there then do a search on Pool Shock here. I use the Leslie's product in my pool so that's what I use, local and cheap. I have chlorine in my tap water so until I need a boost during high heat I rely on my tap.

However if you're in air pots in a soilless substrate do you need that in your res. I only do when my res's hit 78ish. I'm in regular nursery pots in coco.
 
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Wastei

Well-Known Member
You need to get the nutrient solution stable. If you mix a nutrient batch and let it bubble for 24-48 hours how is the pH drift?

Since you're using a readily available complete plant food in a inert medium I think it's either something wrong you're doing in the mixing process of 3-2-1 or the solution is not pH stable long enough.
 

HydroDawg421

Well-Known Member
You need to get the nutrient solution stable. If you mix a nutrient batch and let it bubble for 24-48 hours how is the pH drift?

Since you're using a readily available complete plant food in a inert medium I think it's either something wrong you're doing in the mixing process of 3-2-1 or the solution is not pH stable long enough.
I use a certified scale to measure the Jack's. (I learned the hard way that a cheap kitchen scale is not accurate). It's 100% on point and when measured in the reservoir, the EC/PPM's are precisely what is listed on Jack's feed schedule.

And I don't suffer from pH drift. When mixed it settles right around 5.8 - 5.9 and never moves outside of 5.8 - 6.2 over a 5-7 day period. Earlier this morning I dumped the reservoir and filled it with pH'd water and ran it for 30 minutes to flush. I'm going to use straight water (10 mins every 4 hours) until later this evening then I'll mix in the Jack's 321.

Maybe I was adding too much CalMag + Iron.?

Thanks for everyone's help. I appreciate the guidance., Keep it coming!
 

f03m

Member
Hi, when you have some defficiency you should`t add anything until you identify the real problem. CaMg problems aren`t usually that, but some pH changes, linked to bad fertirrigation. People have a problem and immediately jump to the conclusion it must be CaMg... I don`t understand this.
My advice is check everything, calibrate tools, check your fertirrigation system, but feed as usual, don`t do anything different or you won`t identify the real source of the problem. Make a list. How do you mix your nutrients? Do you follow instructions? Are your tools calibrated? Is the media too dry between drybacks? Are you adding something that make pH spike or go too low?

To be honest I just use a three part fertilizer and plants never needed anything else to grow perfect. What I think is happening with your grow )onlyo my opinion from the outside) is your pH in the reservoir is fluctuating, probably because the media could be too dry sometimes and that makes P accumulate, showing you those black dots, probably if you don`t add the Fe you are adding you should see Fe blocked because of the P excess, new leaves and tips will look very yellowish from the inside to the outside. Like because of your analysis and adding of things, the problem didn`t show as it should, so it will be more difficult to diagnose. This you can solve lowering the EC, fertirrigate as usual, shorter dryback and you will be fine, don`t add more stuff, plants don`t need it.

Good luck.

PS: I saw you flushed with water, NEVER do that again. If you flush, flush with the NS as usual, just a tip. And rememeber, if you have a stone pumper, airstone, or whatever puts air into your reservoir, water will react with the air and will create carbonic acid, which will lower your pH and you won`t notice.
 

Wastei

Well-Known Member
I use a certified scale to measure the Jack's. (I learned the hard way that a cheap kitchen scale is not accurate). It's 100% on point and when measured in the reservoir, the EC/PPM's are precisely what is listed on Jack's feed schedule.

And I don't suffer from pH drift. When mixed it settles right around 5.8 - 5.9 and never moves outside of 5.8 - 6.2 over a 5-7 day period. Earlier this morning I dumped the reservoir and filled it with pH'd water and ran it for 30 minutes to flush. I'm going to use straight water (10 mins every 4 hours) until later this evening then I'll mix in the Jack's 321.

Maybe I was adding too much CalMag + Iron.?

Thanks for everyone's help. I appreciate the guidance., Keep it coming!
You're overall overfeeding causing lockouts. Jacks is already high in Ca so adding more might be contra productive. Especially if you say the solution is stable, no reason to add any buffers.

If you're running CO2 2.4 EC it's really high IMO, especially in veg. I'm more leaning towards root issues like @curious2garden suggested, do you do any root rot preventatives?
 

HydroDawg421

Well-Known Member
You're overall overfeeding causing lockouts. Jacks is already high in Ca so adding more might be contra productive. Especially if you say the solution is stable, no reason to add any buffers.

If you're running CO2 2.4 EC it's really high IMO, especially in veg. I'm more leaning towards root issues like @curious2garden suggested, do you do any root rot preventatives?

OK. I'll turn off the CO2 and I won't add any more CalMag.

I don't think I have root issues. I add a cup of hypochlorous acid to the 12-gallon reservoir every 5-7 days when I mix a fresh batch. I could increase the frequency of this and/or increase the amount that I add. My reservoir is spotless. It stays a constant 65 degrees and when I empty it, there isn't any slime or other concerns.
 

HydroDawg421

Well-Known Member
Hi, when you have some defficiency you should`t add anything until you identify the real problem. CaMg problems aren`t usually that, but some pH changes, linked to bad fertirrigation. People have a problem and immediately jump to the conclusion it must be CaMg... I don`t understand this.
My advice is check everything, calibrate tools, check your fertirrigation system, but feed as usual, don`t do anything different or you won`t identify the real source of the problem. Make a list. How do you mix your nutrients? Do you follow instructions? Are your tools calibrated? Is the media too dry between drybacks? Are you adding something that make pH spike or go too low?

  • Everything listed above I can eliminate. I calibrate every 30 days like clockwork. I have a BlueLab guardian system for constant monitoring and I also check with the BlueLab truncheon meter and a Blue Lab pH pen. So, I have 3 different devices. When I take my readings, they all three line up about 99%.
  • I also use electrode cleaner prior to calibrating.
  • I just broke everything in the room down, cleaned, scrubbed, and disinfected everything about a month ago. The whole room. Top to bottom. Wall to wall. Even the 4x4 flood table was scrubbed spotless.
  • The FloraFlex bubbler, drip rings, and tubing are brand new.
  • I mix exactly per Jack's 321 feed schedule and when measured the EC's, PPM's, etc.. is exactly what is listed on the feed schedule.
    • I start with about 6-8 gallons of fresh water in my reservoir. I mix/add Jack's 321 for a 12-gallon reservoir. Then I add fresh water and dilute down to 2.4 EC and 1200-1600 ppm's (500-700 scale).
    • I used a calibrated water meter to mark where 12-gallon is on the 'tote' that I use and when I measure the final nute solution, the water level is within a '**** hair' of that mark.
  • It's either going to be too much CalMag and/or possibly CO2 in relation to the EC???

To be honest I just use a three part fertilizer and plants never needed anything else to grow perfect. What I think is happening with your grow )onlyo my opinion from the outside) is your pH in the reservoir is fluctuating, probably because the media could be too dry sometimes and that makes P accumulate, showing you those black dots, probably if you don`t add the Fe you are adding you should see Fe blocked because of the P excess, new leaves and tips will look very yellowish from the inside to the outside. Like because of your analysis and adding of things, the problem didn`t show as it should, so it will be more difficult to diagnose. This you can solve lowering the EC, fertirrigate as usual, shorter dryback and you will be fine, don`t add more stuff, plants don`t need it.

  • If anything, I would be concerned that I'm watering too frequently. And my pH doesn't fluctuate. Any 'movement' of the pH is minimal and is expected. It stays between 5.8 - 6.2.

Good luck.

PS: I saw you flushed with water, NEVER do that again. If you flush, flush with the NS as usual, just a tip. And rememeber, if you have a stone pumper, airstone, or whatever puts air into your reservoir, water will react with the air and will create carbonic acid, which will lower your pH and you won`t notice.

  • Explain this to me. And what is 'NS'? I'm not familiar with this abbreviation.
  • I'll also remove the airstone to eliminate that as a source.
 

HydroDawg421

Well-Known Member
if you feed at 2.4 , what is the EC of the runoff when it goes back to the res?

It stays the same. I'm in early veg about 4 weeks in. They are drinking just a little bit of water. Of course, when I add water it will drop to 2.3 or maybe 2.2 but that's also expected. I'm only adding a couple of gallons a week at this point.

When I mix a fresh nute batch later today, I'm going to drop the EC to about 2.0, how's that sound?
 
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Wastei

Well-Known Member
OK. I'll turn off the CO2 and I won't add any more CalMag.

I don't think I have root issues. I add a cup of hypochlorous acid to the 12-gallon reservoir every 5-7 days when I mix a fresh batch. I could increase the frequency of this and/or increase the amount that I add. My reservoir is spotless. It stays a constant 65 degrees and when I empty it, there isn't any slime or other concerns.
Pure hypochlorous acid in solution is not a very effective sterilizing agent in hydro. Shelf life is terrible and you need to apply that two times a day to be effective IMO. If you forget to put the lid on perfectly it degrades quickly.

I think you should look into something more stable with longer residual effect and less dosing frequency.

You want Hypochlorous acid bound to a salt like hypochlorite like sodium/calcium hypochlorite, regular bleach that is. Here's the dilution calculator I've always used Chlorine dilution calculator
 

Wastei

Well-Known Member
It stays the same. I'm in early veg about 4 weeks in. They are drinking just a little bit of water. Of course, when I add water it will drop to 2.3 or maybe 2.2 but that's also expected. I'm only adding a couple of gallons a week at this point.

When I mix a fresh nute batch later today, I'm going to drop the EC to about 2.0, how's that sound?
I think you got all the right answers! Lower EC to 0.8-1.0 like @rkymtnman suggested and change to a better sterilizing agent with longer residual effect.

I'm runnings LED's in veg and my plants are loving life with only 0.6-0.8 EC. I rarely go higher than 1.2 EC in hydro in flower.

You should only increase or lower EC according to plant response. This is the hardest to grasp and master and it takes more than a few cycles to be able to somewhat read what the plant wants.
 
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