recirculating dwc - femmed mango with nute problem

[british green]

Hi I've got a 4x4x7 foot Room with a 600hps and 200w cfl lighting the room . I've got good ventilation and temps are pretty much constant . I have a exhale co2 bag and I'm feeding them with canna nutes a and b Flores . There's a air stone in each bucket and in the res . The plants got flipped about 2 weeks ago and the nutes got changed 5 days ago from Vega to flores and I have this problem with the leaves .

any help would be great . I've have seen the leaf deficiency chart but I have a slight problem with it being colour blind with greens Brown's / reds etc etc . Thanks again Steve

 

[chunky monkey]

Re: recirculating dwc . femmed mango with nute problem

I don't grow dwc pal but that's definitely a magnesium problem what's your ph it should be 5.8 your plant also looks quite dark so I'm going to I think your ph is too high

 

[british green]

Re: recirculating dwc . femmed mango with nute problem

Ph is set and adjusted as needed . I set the ph at 5.5 and it would rise to 5.8 before the res needs changing or topping up .

 

[chunky monkey]

Re: recirculating dwc . femmed mango with nute problem

what ec / ppm are you runnin
g and do you have hard or soft water

 

[british green]

Re: recirculating dwc . femmed mango with nute problem

I have soft water I don't measure the ppm just feed them at half strength and work up .

 

[chunky monkey]

Re: recirculating dwc . femmed mango with nute problem

I would try som magna cal ,soft water contains less mg and calcium so that could be the problem I would also cut back on nutes a bit your leaves look very dark green to me

 

[british green]

Re: recirculating dwc . femmed mango with nute problem

Some more pics under the lamps . The thing that is happening to the leads seem more obvious under the 600hps rather than the cfl side of the room

 

[british green]

Re: recirculating dwc . femmed mango with nute problem

And just in case kjc pops in here the hose it be changed first thing in the morning

 

[Antics]

Re: recirculating dwc . femmed mango with nute problem

It strongly resembles a magnesium deficiency. The fact that it's happening under the stronger light, I would think that the HPS causes the plant to use more nutrients, since more light is available for photosynthesis.

I could be wrong on that second part, I'm just guessing there. But my first guess on the problem is magnesium.

 

[british green]

Re: recirculating dwc . femmed mango with nute problem

That's what I was thinking about the hps side of things . Thanks for the help so far .

 

[Antics]

Re: recirculating dwc . femmed mango with nute problem

Glad I could help a little. Do you have a way to give them a little magnesium boost?

 

[KingJohnC]

Are you using a calcium and magnesium supplement for your plants? Your leaf damage appears to be from a magnesium deficiency.

You want pH 5.8 for hydroponic and soiless (peat moss and coco coir) and pH 6.5 for soil.

Here is a nutrient availability chart

Here is a cannabis leaf deficiency chart

here is the Cannabis Plant and Pest Problem Solver and the Plant Abuse Chart

Cannabis Plant and Pest Problem Solver: Pictorial

Plant Abuse Chart

 

[british green]

I've seen your chart before it just hard for me because I'm colour blind with greens and Brown's . I'm not using any form or magnesium or calcium supplement . I will keep the ph at 5.8 at from now on and i've changed the hose to a drinking water safe pipe . What would you recommend as a magnesium and calcium supplement . Thanks kjc .

 

[KingJohnC]

I use Botanicare's Cal-Mag Plus at 5 milliliters per gallon added to my nutrient mixture. You should discontinue use of calcium and magnesium supplements when you are harvest flushing.

(click on the photograph for a direct link)

 

[british green]

Thanks again kjc . I will purchase this product on monday . It's saturday evening here in the UK and the hose is changed .

 

[KingJohnC]

You are welcome! I am glad that you have changed the regular garden hose to a drinking water safe RV/camping hose for your Recirculating Deep Water Culture system.

 

[british green]

I'll let you know how it goes with photo up dates . Thanks a lot for all your help .

 

[KingJohnC]

You are welcome! I am glad I could help you!

 

[british green]

Ordered online and arriving monday .

 

[Cottonballs]

I have had this problem as well, kjc replied to one of my posts but I had a ph issue and switched nutes to dyna gro, bloom and i added cal mag. It completly solved the yellowing leaf so keep at it and keep updating!