Help.... Possible mg def?

[Vdub818]

I use 63ppm tap water and have been adding calmag+ up to 200ppm total then adding nutes. Now im getting yellowing at the center of 2 fan leaves with some rusty brown spots. Now im grow bible says that is a sign of a mg def. Should I be adding more calmag?

Fyi it's grapefruit under 400mh 3weeks into veg, 5.6 at 70degrees, pbp,liquid karma,calmag+,red thrive alive, running it at a ppm of 1000 at the moment cause 800 was not enough. All new leaves look perfect

 

[tjo]

nute burn i supposed..1000 ppm are to many because i guess
that your plant is not so big..also has burn tips..

 

[Vdub818]

but as I said before at 800ppm all my leaves were extremely light green so I upped to 1000 with my 3rd res change which was the 4th and growth has increased ALOT and now the rest of my leaves are fine. But 2 of my older leaves are doing this now. And none of my leaves are an extremely lush deep green so im not oding nitrogen I don't believe.
And the grow bible doesnt show anything like what I have going on as an overdose. Here are some other leaf tips.

 

[Vdub818]

Bump

 

[oldone]

Hi Vdub818,

I think a "classic" calmag def looks like this;

See the leaf in the lower right? Its a brown spot, yellow leaf kinda thing.

I'm not sure your pic shows that. Have you perused the Infirmary forum?

I do know that once a leaf gets damaged it never repairs itself. It might get worse, but never better. Look closely at the new growth.

You specify your ppm but not its conversion factor. FYI, I used to add .4 EC (800 ppm at .5 conversion) calmag for a coco grow. Hydroton is probably different.

My current feeding is 1.5 EC (750ppm @ .5) in RO water for the entire cycle.

Is this your first grow? Relax, she looks fine and you have plenty of time to learn her ways. Your also at the best site in the world to get help. Lotta very smart people here.

OO

 

[Vdub818]

It's my first in dwc buckets have only used promix before. When I got my meters I got a really nice ph meter but just a cheapo hannah ppm meter. Didn't think I was gonna need an ec meter.

 

[oldone]

Nah, your hanna measures Electrical Connectivity like all TDS meters and then applies a conversion factor to get ppms. Meters can be either .5 or .7

Some of us measure in just EC to avoid confusion. No big deal.

good luck,
OO

 

[Vdub818]

here's a full shot

 

[BeaverHuntr]

That looks like nute burn .. Cal/Mag def leave rusty red spots .