Leaves turning yellow/brown spots/dying/losing green

Hello I have been having some problems with my plants. They have turned yellow, losing color looking almost neon, then ultimately turning brown and dying. I went to my local grow shop and had my water tested, the ppm was around 340-365 ph was 8.7. I was told that there was no real reason to use this water bc it was going to be too hard to control. So I bought a 200 gallon RO water system. Hooked it up to my 60 gallon container with the auto shut off valve on now Im using that water. Starting ppm is now (NO BS) 4-8 ph is 6.4-6.7, great stuff! Ive been using cal+mag with sensi bloom a+b, the leaves still kept getting worse, so snbow I am flushing with just cal+mag. Ofcourse this is based ALL on the fact that my grow shop told me I had cal mag deficiency. Using 3 gal pots with coco 1000watt hps system. Hand water using a wand with pump. Running temp is never over 77 degrees canopy level humidity 35-45%. Plenty of fans running circulating air, even have air conditioner, and on occasion use dry ice for short term CO2 boosts.PH water as needed. WTF IS GOING ON?????????????? plz help me

Looks like one of 3 things... all fixed the same way, but knowing what was done wrong will help make the "fix" permanent...
Either your pH is WAY off and locked-up the plant- You over fed and locked-it-up or she is severely underfed with an incomplete nute mix... what are you feeding/how often? How often do youw ater, and what is the pH of the water/nute solution????

I usually water everyday, however last week when this started I noticed the pots were still heavy and waited for them to clear out a bit before watering again. I always keep my ph under 6.5. Right now it was around 6.8 with just calmag and water. I lowered it slightly with ph down. They were watered today and finally drank for the first time in a while I didn't see them dumping most of the water out the bottom.

I keep my meters tuned and in good shape with help of my local shop, they haven't had any problems with reading yet so I don't think theyre off

Watering way to much

What do you mean you keep your meters tuned with the help of your shop...?

When was the last time YOU calibrated it?

Mattemil said:

What do you mean you keep your meters tuned with the help of your shop...?

When was the last time YOU calibrated it?

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Last week, and a few weeks before that, I constantly have them checked. What signs are you seeing that suggest they are over watered? Ive been consistently told its a cal mag issue

Whats in the soil for drainage? What soil? Seen that from just wet feet.. If no drainage material and 30% perlite and transplant.

anteve said:

What signs are you seeing that suggest they are over watered? Ive been consistently told its a cal mag issue

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Question wasn't posed to me,but I believe the way it works (I'm digging deep into the hazy knowledge of my high school ag science/ffa years here) is that Nitrogen is not transferred well through water, or in wet places. That's why a puddle turns the grass yellow.

Maybe the person that was intended to answer this question has a better response.

definitely a magnesium issue....ph out of range will hamper magnesium uptake..flush with 6.2-6.6 ph water with 1/2 tsp per gallon epsom salt. this is one of the most common problems...