Nutrient Burn RDWC

Gambit79

Member
The Setup:
4 bucket RDWC
4 x 4 tent
Mars Hydro TS 3000 light 80% strength at 30 inches from plants
2 air stones per bucket
Water chiller kept at 65 degrees
General Hydro nutrients measured in 24 gallons
Micro 120 ml
Gro 120 ml
Bloom 60 ml
Rapid Start 60 ml
Floralicious plus 24 ml
Armor Si 24 ml
Diamond Nectar 120 ml
Flora Blend 120 ml
Calimagic 60
Using RO water
Temp between 75 - 80
Humidity between 40% - 50%
PH kept between 5.5 and 6.0

These measurements are based on the General Hydro feed chart generator. https://generalhydroponics.com/feedchart-generator
The plants are 8 weeks from seed, and have been manifolded for 8 colas. The net is just there for support more than scrog.

Through most of these plants lives it was a constant game of keeping PH down, and PPM up. For the past 3 weeks their PPM was around 920 (I was actually adding 28 gallons worth of nutes to 24 gallons of water) and would still go down. I think what happened was since the heater in the house kicked on the temps in tent went up and they just drank more water than usual. Before the tent was at about 75 degrees but now its running between 78 and 79. So yesterday I did a nutrient change after about 6 hours of flushing mixing it at the measurements above and a PPM of about 770. Today the ppm was 780 so added some plain RO water to bring it down to 750. My question is if 6 hours was enough? The PPM of the runoff water was about 40 so I am fairly certain I got the buildup out, but if it has nutrient lockout should I flush longer? Right now the only signs are that the leaf tips got the tell tale sign of burn, and new growth has some yellowing from the inside out. So it seems the nutrient burn probably caused some lockout for immobile nutrients. I am curious how long nutrient lockout has lasted for others using RDWC? I was going to put these guys into flowering next week but not if they are locked out.
 

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BobThe420Builder

Well-Known Member
I've ways ram GH flora trio at full strength in dwc
But not with all that added stuff
Just calmag in veg
Koolbloom and Terpinator in flower
Some silica in early veg

I've never flushed in dwc,not sure it even works

I'd say it's either a ph issue or they are hungry
What's your ph at , or your targetGH-Flora-simple-recirculating.jpgAA7A4BCE-8025-478D-9473-F7FF59161AB6.jpeg
 

Gambit79

Member
PH kept between 5.5 and 6.0. Im 99% sure it is nutrient burn from the heat spike causing it them to take in more water. Those burned tips are a pretty tell tale sign. So if you don't flush how do you fix nutrient burn?
 

Kdoggy

Well-Known Member
I've ways ram GH flora trio at full strength in dwc
But not with all that added stuff
Just calmag in veg
Koolbloom and Terpinator in flower
Some silica in early veg

I've never flushed in dwc,not sure it even works

I'd say it's either a ph issue or they are hungry
What's your ph at , or your targetView attachment 4781140View attachment 4781141
I think if it was hungry you would have lower growth yellowing not upper and not burnt tips i think ph sounds more like a issue but increased temps with plants that arnt used to the higher nute uptake so if he lowers ratio hes probably better off and raise ph to 6.2.
 

Gambit79

Member
I don't think heat, I run 77-80 always

I'd personally simplify all those nutes, way too much and not needed

Keep it simple and manageable


The color of your leaves don't indicated too much N
But if you always run 77 to 80 then your plants water uptake will stay the same for that temp. My temp changed so the amount of water they took up changed. As I said it was only about 74 to 75 in the tent for awhile then it shot up. When the environment changes so do the plants needs.
 

Gambit79

Member
I think if it was hungry you would have lower growth yellowing not upper and not burnt tips i think ph sounds more like a issue but increased temps with plants that arnt used to the higher nute uptake so if he lowers ratio hes probably better off and raise ph to 6.2.
I thought ideal PH in Hydro was 5.8 and soil was 6.2?
 

BobThe420Builder

Well-Known Member
But if you always run 77 to 80 then your plants water uptake will stay the same for that temp. My temp changed so the amount of water they took up changed. As I said it was only about 74 to 75 in the tent for awhile then it shot up. When the environment changes so do the plants needs.
Your talking 5 deg, that wont effect anything


Your 9 different nutes are not working well together

Simplify it or they will really be in bad shape when u flip
 

Gambit79

Member
Ya ideal and real world is diff you get better cal/mg uptake at 6.2 and can run a lower nute mix.
Right on. Thank you guys for your input. If I were to cut out one of these additives how much should I adjust the others? As I said I have been using this https://generalhydroponics.com/feedchart-generator program level expert with a water hardness of 40. Obviously General Hydro wants me to use as much as they can sell, but the ratios should be correct right?
 

Gambit79

Member
Also I will do as you suggest and let it get to 6.2 and just adjust it down if it gets to 6.5. It does kinda look like a combo of nute burn and calc deff to me.
 

rkymtnman

Well-Known Member
So yesterday I did a nutrient change after about 6 hours of flushing mixing it at the measurements above and a PPM of about 770. Today the ppm was 780
not long enough a flush. i go minimum 12hrs.
and too high ppm after the flush.

after a flush, they should eat like crazy.

since you just did a flush, add a bunch more RO to get your ppm down to like 500 and see if they start eating.

and simplify: GH trio, cal/mg, RO water.
 

Gambit79

Member
not long enough a flush. i go minimum 12hrs.
and too high ppm after the flush.

after a flush, they should eat like crazy.

since you just did a flush, add a bunch more RO to get your ppm down to like 500 and see if they start eating.

and simplify: GH trio, cal/mg, RO water.
Right on Thanks! I will do just that. Do you think it is ok to keep the floralicious plus with the trio and cal mag? Can sugar burn the plan? I honestly care more about taste than yield.
 
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