Sudden onset of dying leaves - Possible PH problem

Hey guy's I was going downstairs because my plants where looking great a day or two ago and I was taking pictures to start my Auto Grow journal so I could start sharing. I go down today and I find on three of my four plants spots all over the leaves. I had started feeding with Technaflora Bloom mix at 1/4 ratio of what was recommended and was mixing it with R/O water. I had done Feed Water Water Feed and then I was onto my first water as of tomorrow after the feed but noticed these spots.

I made sure to buffer my PH of my nutrient solutions but I had suspected I may have had a low PH issue to begin with way before. Also I believed I had a MG/Cal def at first because of not adding any to my R/O water. I sprayed all of my plants with 1tsp of epsom salt to a gal of water and the plants turned around about a week ago and now this.

Upon testing the Water PH going in it was at 7.7

Water coming out into the bottom basin is at 5.2

Now I am assuming this a nutrient lockout but I am not entirely sure. If anyone that has seen this more often could comment I would really appreciate it. This is a Auto Afghan Kush about 28 days old.

Soil Using - Dr Earth Potting Soil -(yes I am switching to Fox Farm ocean forest after this grow. I have realized this soil sucks and doesn't buffer PH properly at all. I also mixed in perlite)

Light - 18/6 HPS 400 watt

This is affecting the entire plant and appears to have started from the bottom nd is moving up. The very top leaves haven't started to do this but it stinks because my plants are just starting to really start budding and I don't want to loose them.


Big thanks for any information you can help out with. I have looked at other topics but can't really seem to nail exactly what it may be. I was thinking either PH lockout because its starting in the middle or Potassium issue but that would also be with Nute lockout so idk.

Its probably a OD of something. Most likely due to the ph being off. You dont necessarily need to burn a plant by over feeding it, off PH will do it also. Smaller plants are more sensitive. Ph going in at 7.7 & out at 5.2 is a sure sign of a acidic soil. Do you have a soil ph tester? You can also test the soil ph by mixing 1 part soil to 4 parts RO water. I think thats the ration, if I remember correctly. Been a long time since I played in the dirt. But isn't it limestone that should be mixed with soil to keep it from getting acidic? Double check on that but im pretty sure. Good luck.

mr. green thumb 01 said:

Its probably a OD of something. Most likely due to the ph being off. You dont necessarily need to burn a plant by over feeding it, off PH will do it also. Smaller plants are more sensitive. Ph going in at 7.7 & out at 5.2 is a sure sign of a acidic soil. Do you have a soil ph tester? You can also test the soil ph by mixing 1 part soil to 4 parts RO water. I think thats the ration, if I remember correctly. Been a long time since I played in the dirt. But isn't it limestone that should be mixed with soil to keep it from getting acidic? Double check on that but im pretty sure. Good luck.

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Yea I am definitely assuming the soil is very acidic. I believe it is Dolomite Lime but seeing how I am already 30 days into my grow with my auto's im not sure if I can even mix any into my soil without screwing it up.

I have a Soil PH tester but I read they are beyond inaccurate which I am going to have to agree with. I never heard the mixing 1 part soil to 4 parts RO Water would you then take the drops and just put them in like normal once the soil settles?

I am going to be buying a PH tester but I can see the huge change in PH from going in to coming out just by using the drops alone.

Thanks for responding much appreciated.

Alright guys I took new pictures of the plants. I flushed last night with straight tap water ph of about 7.7 and it first was coming out at around 4.0 and I got it to about 5.0 and the PPM of the solution was at about 300ppm (tap water is at 100ppm). As you can see there is some serious issues going on here and im not entirely sure what I should do without killing my plant anymore... as you can see the dying seems to have started at the bottom and is moving its way upwards. I am trying to save the top half of the plant if possible as that is where it appears most of the bud is starting to form. These are in there first week of actual flowering I would say and are Auto afghan kush.

They are in two 8in pots stacked ontop of eachother with a hole cut through the bottom of the first pot so its wide open. I did this to prevent transplanting basically because i realized they where in to small of pots. I did this weeks ago so nothing related there.

in this plant I flushed about 3 gallons through it it has about a gallon and a half of soil.



I am at this point pretty certain that it is a PH lockout issue but the question is how do I recover from it with minimal impact to the flowering? I have been reading constantly but it seems people just keep saying mix Dolomite Lime into the soil (but this is obviously slow acting over time and should be used as a preventative. I did flush with higher PH water but it appears the plants just keep dropping in PH)

With the ro soil test your right on with what you said. I use a ph meter but if you only have the drops then they will work also. You can use the d.l as a top dressing. It doesn't need to be mixed throughout the soil. What kind of soil are you using? It your water is going in at 100 and coming out at 300 ppm then thene is nutes in the soil. It could be salt accumulation or that there is just plenty of nutes in the soil already. Is it reused soil? Overfeeding can also cause ph drops.

you can still use lime to change the ph, sprinkle the fine dust of it over the soil and water down, it will help, probably wont cure entirely though

I was using the Dr. Earth Potting Soil mixed with peatmoss and Perlite. Clearly the Dr. Earth is going bye bye after this grow and I Am switching to FFOF.

My question is for water to be at a 7.8 ph and it to be coming out around 5 that would mean the soil has to be extremely acidic.... Any idea what would cause this? I have only fed 1/4 nutrients twice over the entire grow so I am doubting it is salt build up... I am just trying to figure out why even though I pour gallons of water through it to flush it the PH doesnt really rise very much? Any ideas?

it's probably because the soil is just acidic (good idea to change), plain water doesnt change ph much unless the low ph was caused by a salt buildup. you need actual neutralising material in the mix like lime.

I would point towards salt build up, have you been feeding for awhile?? How often do you flush? Have you ever flushed? Do you own a ppm meter (tds), you really shouldn't have jumped to nutes before doing anything else. I would flush very well lay off nutes for awhile and add a little dolomite lime after flushed

I've only fed twice both times at around 450 ppm using to Ro water with 2ppm to start. That's 1/4 dose from technaflora. When I flushed last night the ppm was at 298 using my tap water of 100 ppm so that means on avg there is a about 198ppm of nutrients? I don't think it's a huge salt buildup but I'm new to this so ?

Anyway remember these are autos so once I rectify the issue I do need to feed again because these will only be alive for another 30 to 45 days

Update- Its been 2 days since I flushed my plants. I am noticing that the dying has started to wear off but the leaves are now starting to looking yellower and dots are starting to form almost what looks like a potassium defeciency. I flushed one of my smaller plants in a smaller pot that already was dry about a inch down and the Runoff was still around 5.0 I was flushing with 8 ph water... I flushed about 4 gallons through with no change really in the runoff... PPM was at 200ppm my water is 104 ppm before flushing... SO not sure exactly what is causing this huge PH drop

Any ideas?

Your PH measurement has to be off or you have some wack soil.

Ok guys I appreciate all of the help so far... as you can see its been about a week and a half I went and got dolomite lime and mixed it in to each pot. I then watered with PHed water with 100ppm and the runoff was coming out very low with about 300ppm.

I then waited 3 days and then flushed with a 7.9ph water in each one for instance I flushed about 5 gallons of water through a 2.5 gallon container and the PH of the water came out about 5.0 to 5.5... I have checked to make sure my ph drops arent off which they arent I test my tap water and it shows about 7.3 I test my RO water and its about 6.0 which is pretty accurate. So I flushed all of the plants again and waited another three days for them to dry... I then watered with PH 7.9 again thinking that with the Dolomite lime mixed in and then watering with a 7.9ph water and the runoff is still coming out around 5.0 I waited another couple of days and did another flush and i am still getting the lower ph so I am not entirely sure what is going on now as i am assuming its still nute lockout but maybe I am crazy? I have literally tried everything and these plants are auto's so transplanting can't happen as it will just stunt the flowering stage at this point... I really need some help on this one as I am stumped to all hell... i can tell you this I will never use this Dr.Earth soil again I have already picked up a bag of FFOF but obviously i can't switch now lol.

Thanks for your help

Just a quick update I looked up my Tap water report (i do have a ro filter but I believe using RO is what got me to this problem to begin with without offsetting PH or Cal/Mag - newb mistake)

I have been flushing with tap and getting a yellow looking liquid although i have only fed twice in three weeks... but anyways I tested the ppm of the water on flush and its about 200ppm my tap is about 110ppm

Below is my water quality test

Sodium-4.83PPM
Lead PPB- 1.1
Copper - .056PPM
TTHM- 20.6PPB
HAA5- 15.3PPB
Residual Clorine - .80PPM
Flouride - .98PPM
Nitrate - .30PPM
Barium- .01ppm
Selenium- 1ppb

I foliar fed with a very light nutrient solution as I am quite worried and still trying to figoure this out... Anyone have any comments on the water quality? I think it looks pretty good but I googled and searched the forum for a guide on reading the exact values and what is acceptable on each item but didn't really find much other than Sodium can be bad in higher levels and cause a salt build up but I don't think 4ppm is very high?

Thanks for any help

1st pic is potassium deficiency. Pretty far along too. Did you transplant?

Hate to say it but those pretty much look shot. Might be time to cut the tow line and let that scow sink.

Check this out. Hempy is a proven and easy method to get good bud and a lot of it cheap. Go here and tell Moebius I sent you. He might be able to help you save that but I say lame horses aren't worth riding.

https://www.rollitup.org/hydroponics-aeroponics/546006-world-hempy.html

You'll never look at a 2 liter soda bottle the same way again.

I started down that road.....I had a couple fan leaves do just that.
Then started to reduce the water cycle till I got sag....no more messed up leaves.
just tryin to help

hotrodharley said:

1st pic is potassium deficiency. Pretty far along too. Did you transplant?

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I had transplanted them ages ago as they are Auto plants (which I have learned now NOT to transplant just start them in quality soil and in the size pot you plan on finishing in) clearly I know I have learned numerous things from this grow alone but as you can see they have been in flower about 2 weeks now and I really want to try and save them. I am going to start doing some research now on Potassium Def -

The issue I seem to be having is getting my PH of my soil up... I have used Dolomite lime mixed in and also have mixed it into my water once and it has been about a week and a half and I have yet to see any improvement in the PH really it seems to be staying at about 5.0 with two flushes of 7.9 water


Thanks for all your help and replying I definitely appreciate you pointing me in the right direction