Cal mag deficiency in rdwc

White.Black

Well-Known Member
Hello. I'm having major issues in late flower stage with cal mag deficiency, or what appears to be (to me).

I have northern lights plant that went almost completely brown and i consider it as dead:
20230511_081743.jpg

And now it started sort of happening on white widow and royal runtz:

20230511_081527.jpg20230511_081532.jpg20230511_081539.jpg

I have another plant in another tent but in DWC and its not happening there. For some reason just in rdwc where i have 4 plants.

Any thoughts on this? Im quite sure that i'm giving them enough cal mag supplement.
For 40 liters of water i add 20 ml of calmag, and I have around 50-60 liters in total...

Ph is 5.8
Ec is 720

Yesterday i took a pint of water, and squirted in about 50ml of calmag, mixed it up and added to the rdwc reservoir. Problem seem to be worse now.
 

White.Black

Well-Known Member
Nutes are generic sort of clone of general hydroponics, and cal mag is also locally made.

Temp is 25c, humidity 50%, lights are led mars hydro, water is local tap water.

I did not mention this because im in Thailand, and all products i use are local to Th...but having said that, this is just happenibg in rdwc system, not in dwc in another tent where i only have 1 plant. That one is showing no signs of calmag deficiency.

My instinct is saying that i should increase cal mag supplement in rdwc because there are 4 plants sharing the same nute solution. Im somwhat afraid that its not calmag that is the primary cause of the problem, and if i do this, i will make the issue even worse.
 

Wastei

Well-Known Member
Nutes are generic sort of clone of general hydroponics, and cal mag is also locally made.

Temp is 25c, humidity 50%, lights are led mars hydro, water is local tap water.

I did not mention this because im in Thailand, and all products i use are local to Th...but having said that, this is just happenibg in rdwc system, not in dwc in another tent where i only have 1 plant. That one is showing no signs of calmag deficiency.

My instinct is saying that i should increase cal mag supplement in rdwc because there are 4 plants sharing the same nute solution. Im somwhat afraid that its not calmag that is the primary cause of the problem, and if i do this, i will make the issue even worse.
You probably have root rot if you don't do any preventative measures? It's not a matter of if but when do you get root rot? "Cal-mag" should not be needed with a complete plant food in DWC. EC 720? You mean ppm at 0,5 scale? 730 microsiemens is still way to low for flowering plants in DWC.

Coir is the medium of choice in Thailand for obvious reasons. You will always struggle with DWC and keeping water temps down.
 
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Mr. Mohaskey

Well-Known Member
Could be root issues as Wastei suggested. Were these clones? If so and 1 clone had an issue it could spread to the others in the rdwc. What's in your source water? Is it testable in Thailand
 

White.Black

Well-Known Member
I don't think it's bugs. This is inside the airconditioned room in grow tents, of course it still can be...but very unlikely. It's nutrient imbalance of some sort. But it's strange because it does not happen in DWC where I have one plant, it happens in RDWC where I have 4 plants sharing the same nutrient solution. They are not clones.

So... to be clear. I have DWC in one tent with 1 plant, and RDWC in another tent, with 4 plants sharing the same nutrient solution. The problem is in the RDWC tent, not the DWC tent...and I'm feeding them exactly the same.

In RDWC, I have 3 different plants. Northern lights one, 2 white widow and 1 royal runtz. Royal Runtz seem to be in best shape by far, while northern lights is basically dead.

I'm adding a quarter to a half of what's specified on the label NutraGrow, NutraMicro, NutraBloom (the GH clone locally made in Th). You can see that this is named similar to GH, FloraGro, FloraMicro and FloraBloom.

So, last top up was:
40 liters of water, or 10 gallons
40ml of NutraMicro
70ml of NutraBloom
20ml of Cal-Mag
Squirted some hydroguard in.

There was already about 20 to 30 liters of water in there..so total is 70 liters, or 19 gallons.

I run water chillers, and water is kept at 20c. Hydroguard is used as well to maintain root health.
Rooms are air conditioned, so heat and humidity are not a problem.

Here are more pictures...
 

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bubblescrogs

Well-Known Member
I've seen similar from hitting them too early with large doses of PK or CalMag when they don't need it. Excess can look a lot like deficiency (and cause lock outs of other things). Maybe cut out the CalMag next time until you notice a problem that requires it
 

Wastei

Well-Known Member
I don't think it's bugs. This is inside the airconditioned room in grow tents, of course it still can be...but very unlikely. It's nutrient imbalance of some sort. But it's strange because it does not happen in DWC where I have one plant, it happens in RDWC where I have 4 plants sharing the same nutrient solution. They are not clones.

So... to be clear. I have DWC in one tent with 1 plant, and RDWC in another tent, with 4 plants sharing the same nutrient solution. The problem is in the RDWC tent, not the DWC tent...and I'm feeding them exactly the same.

In RDWC, I have 3 different plants. Northern lights one, 2 white widow and 1 royal runtz. Royal Runtz seem to be in best shape by far, while northern lights is basically dead.

I'm adding a quarter to a half of what's specified on the label NutraGrow, NutraMicro, NutraBloom (the GH clone locally made in Th). You can see that this is named similar to GH, FloraGro, FloraMicro and FloraBloom.

So, last top up was:
40 liters of water, or 10 gallons
40ml of NutraMicro
70ml of NutraBloom
20ml of Cal-Mag
Squirted some hydroguard in.

There was already about 20 to 30 liters of water in there..so total is 70 liters, or 19 gallons.

I run water chillers, and water is kept at 20c. Hydroguard is used as well to maintain root health.
Rooms are air conditioned, so heat and humidity are not a problem.

Here are more pictures...
"Squirted some Hydroguard?" Lol! I think this is your main problem, Hydroguards is not very effective as a preventative from the get go, it's heavily diluted and if it's not stored correctly it may go bad. If you don't dose it accurately it may even be contra productive. I've seen people experience root rot with using to much Hydroguard.

Depending on what "Calmag" you use I would second it sounding like a way to high dosage. You should only add back the buffer and you should not need max dosage to achieve that! You're new and your plants look way overfed.
 

White.Black

Well-Known Member
"Squirted some Hydroguard?" Lol! I think this is your main problem, Hydroguards is not very effective as a preventative from the get go, it's heavily diluted and if it's not stored correctly it may go bad. If you don't dose it accurately it may even be contra productive. I've seen people experience root rot with using to much Hydroguard.

Depending on what "Calmag" you use I would second it sounding like a way to high dosage. You should only add back the buffer and you should not need max dosage to achieve that! You're new and your plants look way overfed.
This is the calmag, though I'm afraid it's not going to be helpful since this is some generic thai no brand mixture. I had success with using this in my previous grow, and my skywalker og in the DWC tent is looking great.

I use very small amounts of hydroguard, maybe 5 ml or so on 10 gallons of water (on the label it says 2 ml per gallon).
Reason is again, I had success doing this previously, and the skywalker in the DWC tent is doing OK. I don't pay too much attention to hydroguard dosage, because i use very small amounts, and keep the water cooled down to 19-20c and i took care that there's no light leaking into the system.

When I harvested my previous plant, the roots looked immaculate... so I'm basically just repeating what I did before and it works for the DWC tent, but it doesn't for RDWC.

I'm clearly doing something wrong(you think this looks like overfeeding?), and I hope I will push through another 2-3 weeks for this batch to be finished and on the next one will be more careful and precise with dosages.
 

White.Black

Well-Known Member
I've seen similar from hitting them too early with large doses of PK or CalMag when they don't need it. Excess can look a lot like deficiency (and cause lock outs of other things). Maybe cut out the CalMag next time until you notice a problem that requires it
Ok, I just topped up my reservoir yesterday. I did not add any calmag this time, so what was already in the reservoir is heavily diluted now.
Will stop it completely. I think I have 2-3 weeks until harvest, hope it pushes through.
 

Wastei

Well-Known Member
This is the calmag, though I'm afraid it's not going to be helpful since this is some generic thai no brand mixture. I had success with using this in my previous grow, and my skywalker og in the DWC tent is looking great.

I use very small amounts of hydroguard, maybe 5 ml or so on 10 gallons of water (on the label it says 2 ml per gallon).
Reason is again, I had success doing this previously, and the skywalker in the DWC tent is doing OK. I don't pay too much attention to hydroguard dosage, because i use very small amounts, and keep the water cooled down to 19-20c and i took care that there's no light leaking into the system.

When I harvested my previous plant, the roots looked immaculate... so I'm basically just repeating what I did before and it works for the DWC tent, but it doesn't for RDWC.

I'm clearly doing something wrong(you think this looks like overfeeding?), and I hope I will push through another 2-3 weeks for this batch to be finished and on the next one will be more careful and precise with dosages.
Looks like it's a copy of AN's Cal-mag with Calcium nitrate, mag sulfate and iron chelate. You haven't stated your actual EC so I'm unable to help without any data to work with. What nutrient strength do you use? How often do you do res changes?

Don't trust your cheap EC/tds meter without calibration. Buy a reputable brand like HM 80.
 
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