Is this a phosphorus deficiency?

Hi guys, I was just looking for an opinion, do you guys think this Is a phosphorus deficiency?

Magnesium. Feed cal mag.

hotrodharley said:

Magnesium. Feed cal mag.

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So do you think its magnesium? I feed them a bit of calmag but it takes a few days to kick in, that's a better pic of what's going on

Why don't you discuss more of what the grow is like? Is this hydro? What nutrients are you using and what ppm level? How close is the light, what's the wattage, and what are you air temps like?

It's in rdwc I have a 600watt m/h bulb in a 5'x5'x6.5' my rez temp is 20°c/68°f and my room temp is 18-22°c/64-72°f and my ec is .8 and I'm running cyco nutes I have a 6" fan for exhaust their in their 4th week of veg MH light is about 2 foot away

polishpollack said:

Why don't you discuss more of what the grow is like? Is this hydro? What nutrients are you using and what ppm level? How close is the light, what's the wattage, and what are you air temps like?

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I think .8 ec is about 550ppm on the 700 scale

Check your roots if you can she doesn't seem to be pulling water up her for whatever reason maybe root rot
Hence the dropping

makka said:

Check your roots if you can she doesn't seem to be pulling water up her for whatever reason maybe root rot
Hence the dropping

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They have only just been in dwc for about 2 weeks so I've only got a few roots that have just hit the water but I have been top feeding, they were big clones when I transplanted them and my rez temp was too cold so I think I drowned them a bit to start with

Converting ec to ppm always varies depending on what meter you use. I think 0.8 is too low. I'd suggest taking it up to 1.2 or 1.3, maybe even higher depending on how those work. But again, an accurate understanding is difficult and based on which meter you have.

Some more pics

polishpollack said:

Converting ec to ppm always varies depending on what meter you use. I think 0.8 is too low. I'd suggest taking it up to 1.2 or 1.3, maybe even higher depending on how those work. But again, an accurate understanding is difficult and based on which meter you have.

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I'll put some more base nutes in and see how it goes

How often have you been top feeding them because if it's pure hydroton they dry out seriously fast especially under hps
I think once your roots are in the water and the ec is right they will take off and green up
Imo I think they are underwatered and underfed
I know you say you watered to much but I use to run my hydroton top feed to water 15 min every hour in a recirc system (wilma) and never once had an overwater problem
BUT did have some issues underwatering when it was real hot

I would bump them to 1ec first see how they are a .5 increase at once may shock them a little if they are already hungry
And slowly increase
I ran dwc for years and never went above 1.5 ec for any grow
Just my 2 pence worth

makka said:

I would bump them to 1ec first see how they are a .5 increase at once may shock them a little if they are already hungry
And slowly increase
I ran dwc for years and never went above 1.5 ec for any grow
Just my 2 pence worth

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I dont think I had enough oxygen pumping in when I first put them in and my rez temp was around 46-47°f so I got a water heater the temps are much better now, yeah I'm using hydrotron I had the water am inch above the bottom to start but now it's just under so the bubbles and that keep the bottoms of the net pot wet, I've had my top feed running one hour on 2 off