Leaves brittle and beginning to canoe and twist

Hello, I have been trolling the threads for awhile now, this is my first post and would like to start by saying THANK YOU! to everyone on here....I have gained a lot of valuable information by reading many different people's posts.
I have looked all over (several forums as well as google and a few different problem solver charts) and tried several things to fix the problem, but can't seem to get it to stop. This has happened my last 3 or so cycles. The leaves get some brown spots and chlorosis and turn brittle while they are still mostly green. They are always fine in veg, the problem starts within the first week of flower. The middle and lower portions are affected equally, but it doesn't affect the very tops of the plants.

Indoor grow in soil. The soil is a mix of several things that I don't remember. The first round with this soil, I used straight water and they produced very poorly (leading me to believe the soil is low on nutrients) and this same thing happened with the leaves so the second cycle I started giving Flora Nova Bloom (4-8-7) and they produced better, but still had this same problem. I have tried cal/mag with no change, tried to up the p and k with no change. Have also tried epsom salts with no change. It seems like I have tried other things too, but can't remember.
I use the lift method for watering and if I'm not sure I check the top couple inches or so with a finger.

600w Lights are plenty far enough away from the plants (roughly 3')
CO2 at 1500ppm
Temps: 80 degrees give or take 1 or 2. Plenty of air circulation.
Humidity: 40-50%
Nutes: Have tried several over the coarse of the last few grows and nothing seems to fix the problem.
Strains: White Rhino and Chanel + (both are affected the same)

Here are some pictures (I think there are 3 different plants I took pictures of, maybe 2)

Is your water coming out of a water softening system that uses salt pellets to soften the water? Or maybe it is well water with a very high ppm?

Looks like necrosis caused by too low PH. If your PH is fine, I would say salt build up is the culpret and needs to be flushed.

Honestly, I don't ph. It's an organic soil and there is plenty of lime in there to keep the ph in check. I am using the flora nova now, but I did a water only grow with this soil and it did the exact same thing, but did not produce very well leading me to the conclusion that the soil is low on p and possibly k which is why I am now adding nutrients. I am sure there is no salt buildup as I am still using no nutrients in veg, therefor no salts, and they are completely fine. This shows up within the first week of switching to flower (separate room) and shows whether I add nutrients or not. Being that it shows very shortly after switching to the flower room I have been wondering if it is an environmental problem, but from everything I have read, temp and humidity is where it should be and there is lots of air circulation. I am not one to typically ask for help, but I am rather stumped.

Btw, Thank you for the reply Taking your time to read and post is greatly appreciated whether I agree or not. Even a post I don't agree with has the possibility of leading me toward a solution.

I would say sensitivity to heat, or overwatering would be the culprits...Use only water for a week or two as well

mrgreen40 said:

Honestly, I don't ph. It's an organic soil and there is plenty of lime in there to keep the ph in check. I am using the flora nova now, but I did a water only grow with this soil and it did the exact same thing, but did not produce very well leading me to the conclusion that the soil is low on p and possibly k which is why I am now adding nutrients. I am sure there is no salt buildup as I am still using no nutrients in veg, therefor no salts, and they are completely fine. This shows up within the first week of switching to flower (separate room) and shows whether I add nutrients or not. Being that it shows very shortly after switching to the flower room I have been wondering if it is an environmental problem, but from everything I have read, temp and humidity is where it should be and there is lots of air circulation. I am not one to typically ask for help, but I am rather stumped.

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You can have a salt problem without feeding, that is why I asked about your source water possibly being softened.

Have you tried veg nutes mixed with a small dose of epsom (tap water) or calmag (RO)? That plant isn't asking for bloom nutes yet and it could be building up. It definitely looks locked out from something.....

Perhaps your water is too hard as suggested above?

next time start with a good soil, like FFOF, not one of your untested creations. That will get you to flower easily with no problems as long as the water your pouring in is PH'd close to where it should be.

A bunch of those pics show classic PH fluctuations???

Ok, It is city water and is ran through a rv charcoal filter, but that's it. It's not softened and same thing was happening before the charcoal filter. I will ph the water over the next couple days and see if there are any major fluctuations, assuming my ph meter still works lol. I have also switched to sunshine mix #4 for the next round which will start in about 5 weeks, but was hoping to figure it out for this round. I will be sure to post any changes whether they be good or bad as I try different things.
Thank you to everyone for the suggestions they are much appreciated.

Could it possibly be a problem with water retention? I don't water until I can shove my finger all the way in and have it not feel damp, so at least the top 3" is dry, but it does seem to take awhile for it to dry out that much....something in the area of a week whereas when I was using pro-mix I was watering approx every 3-4 days.

mrgreen40 said:

Could it possibly be a problem with water retention? I don't water until I can shove my finger all the way in and have it not feel damp, so at least the top 3" is dry, but it does seem to take awhile for it to dry out that much....something in the area of a week whereas when I was using pro-mix I was watering approx every 3-4 days.

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bugeye is right if you read TOL by the rev. he go over salts. a revers osmosis water system will remove the salt when you use tap water you have to flush it then put it into flower. i prommis the book is worth the read.

For my own reference right now, water with nothing added is at 7.2 ph using pool test strips as I can not find my ph meter.

I'm certainly not saying it can't be salt buildup, but if it is, the thing I do not understand is how my veg plants never do this and I have mothers that are older than anything in flower and have never been flushed. If it was salt buildup, wouldn't these mothers be displaying the same problems? Again, not arguing it, just trying to understand it.

mrgreen40 said:

I'm certainly not saying it can't be salt buildup, but if it is, the thing I do not understand is how my veg plants never do this and I have mothers that are older than anything in flower and have never been flushed. If it was salt buildup, wouldn't these mothers be displaying the same problems? Again, not arguing it, just trying to understand it.

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Probably not salt build up if you are filtering your water. I'd recommend doing a $5 soil test on your soil to see if anything is too hot or too cold.

Ok, bought a soil test kit yesterday. I hear these aren't always very accurate, but it shows ph at about 7.5, nitrogen is high and p & k are both low.
I looked it up and seems sulfuric acid may be the best way to drop the ph. I am going to see if i can find some today

Are you a cig smoker? check out the tobacco mosaic virus. Seems like you shouldnt have issues with how you are doing things unless its something that is uncontrollable, like the virus

Ph is too high for soil IMO.

Rolling1up said:

Are you a cig smoker? check out the tobacco mosaic virus. Seems like you shouldnt have issues with how you are doing things unless its something that is uncontrollable, like the virus

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The symptoms do look somewhat similar, but sounds like it is spread around fairly easily and I go between the veg and flower rooms frequently and nothing in my veg room is having these problems. I keep everything pretty clean, but will be sure to go over the room and sterilize everything extra good once this cycle is over. Thank you for the suggestion and thank you to all who have responded