Please help me Diagnose my Plant Problem

I have about 12 Mango plants that just went into Flower 2 weeks ago.
Almost all of the plants are showing the same symptoms. See Pictures.

Setup:
Soil Grow with Fox Farm Soil

Nutrients Fox Farm Big Grow is all Iv used so far. I plan on adding the Big Bloom and Tiger Bloom in the next feeding.

2 600W HPS Lights

My Room gets up to 75 degree's during the day and about 60 at night.

Iv been a little lazy about checking the PH of the water before watering and i think its been pretty high. maybe 7.5

It seems to me like its some kind of nutrient deficiency. Its not only leaves near the top of the plant but also leaves on the bottom of the plant.

In photo #2 Im trying to show how a few of the leaves are pointing to the side? Iv never seen that before...

Any help would be greatly appreciated.

...when was your last transplant? ...have you added any cal./mag? ...tap water or RO?

Do you have any pictures of the whole plant?

it will be hard to tell the correct course of action until you bring your ph runoff to acceptable levels

I have the same problem. ( my leaves look like yours) I think your light is to intense or too close. I check my PH daily and i keep it right at 5.9 (Ebb in flow hydro) so I dont think it is your Ph. but u should fix your Ph!!!! And for a cal/mag def i dont think so cause I use calmag and i know its in the water..... try backing your light off and be careful when water,,, u dont want droplets of fertizlizer to hit the leaves.

..when was your last transplant? ...have you added any cal./mag? ...tap water or RO?

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I transplanted a few weeks before going into Flower so now its been about 4 weeks.

I have not added any Cal-Mag. Do you think thats a good idea?

Im using tap water. it never bothered my plants before but like I said, I have become a little lazy with the PH levels.

Do you have any pictures of the whole plant?

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Yes, I will post them tomorrow when the lights are back on in the room.

I have the same problem. ( my leaves look like yours) I think your light is to intense or too close.

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I really dont think the heat from the lights is a problem. The hoods are vented and the light is currently close to 3 feet from the top of the plant.

Thanks for all the input everyone. Much appreciated.

I don't think it is light burn either. pH problem is the most likely suspect. The brown rusty spots could also indicate a calcium deficiency. This is probably because your pH is off and the plant can't absorb it.

Try adding some cal/mag after you get your pH corrected.

^^^Thats whats up. I got a mango 2 weeks into flower, its a pretty hearty plant and i vegged too long now i have a shrub.

So after about a week of trying to get the PH under control Im still seeing lots of leaves drying out. (see picture)
Iv watered 2 times in the last week. I added a small amount of cal-mag on the second watering.

Any other ideas after seeing this picture? Each plant has about 10+ leaves that look like this or worse.

I know it takes time to correct problems in soil but Im getting anxious!

Thanks for all the help

As long as your new growth isn't being affected I think you're OK. The Cal/Mag damage will continue for a while after you have fixed the problem, so you will get some dying leaves. Make sure to keep your pH at 6.5 to 6.8, and expect some of the leaves to die.

Thats kind of what I thought. The new growth looks fine so hopefully everything will be okay.

thanks for the help.