Possible pH fluctuations?

Hello, I currently am in day 5 of flowering of my first grow, noticed some brown spots on one fan leaf, didn't really think much of it. It appears to be spreading, although the plant itself is thriving. I'm growing in FFOF soil, and using the FF trio. The pH levels in the tap comes out quite high around 8, so I use pH down to get it to around 6.7. Pics on the web seem to lean towards pH fluctuations if the pH is high(7+). I figure next watering I should lower the pH to 5.9 or something to even it out a bit? The pH of the run off water comes out around 6.7 if that matters. Strange thing is her sister ( clones from the same mom) hasn't shown any spots and is just as vigorous. Just wanted to get some insight, thanks!

a pH that high suggests your water is quite hard, so it could have a lot of calcium carbonate which may affect other elements in the plant - even though you pH down it wont remove the cc that builds up in the soil i think
do you have another water source available?

What part of the plant did you pull that leaf from? If it was the lower part I'm thinking Ca deficiency. Experiencing any light green new growth or is it fairly consistent?

The effected leaves are about mid center, new growth looks healthy. I can always buy gallons of distilled water at the store. Just seems strange that her sister isn't showing any weird symptoms, both fed and watered with the same stuff.

Xexmey said:

The effected leaves are about mid center, new growth looks healthy. I can always buy gallons of distilled water at the store. Just seems strange that her sister isn't showing any weird symptoms, both fed and watered with the same stuff.

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thats really weird, overall pic of the plant would help

That looks more like water damage than any deficiency. Unless the same thing is happening to the same class of leaves all over the plant at the same time it's not any kind of deficiency.

If you spray your plants . . . don't. No need for it unless you got bugs or a confirmed deficiency you're trying to fix quicker thru foliar feeding.

Maybe it got splashed while watering but it's not a serious thing and trying to correct a problem that's not there just leads to real problems.

I use RO water only but if that isn't an option for you maybe get some distilled and mix it with your tap water to reduce the ppm. Those minerals in your water will build up in the pots with every watering and will need to be flushed out once in a while or you'll get to experience all sorts of problems down the road. With hard water you can use pH down to get it right, let sit overnight and it's back up again as the carbonates are slow to react to the weak acid and can take a lot of pH down to get it stable.

Good luck.

You might be on to something there OldMedUser. Few more details probably will help out here and I'll post a full pic once the lights come back on. This is a micro grow in a 3 ft tall box I built, mainly for stealth. Since the space is so height restricted I have a screen to keep them low, not technically a scrog as I'm just spreading the new growth along the screen. It was a bit hard to water them at first so I'd just dump the water on gently but I now have some tubing to get under the canopy so I'm not getting any more water on the leaves. So far I have learned a lot and will be better prepared for my next grow.

If you don't learn something with every grow you're not paying attention.

Checked on them at lights on and saw # 1 drooping quite a bit, # 2 showing a slight droop. Been almost a week since I've watered so I fed them both and waited an hour so you didn't see any sad hungry plants. Forgot I had a water purifier on the sink, came out around 6.3 so much better then without. After an hour they looked much happier and I really couldn't find too many other leaves affected by the spots, just the one leaf. This will be the official first week of flowering and wow, they really do take off. GSC clones if you are curious.

What kind of purifier is that? Very odd that it would reduce the pH unless it was a distiller or RO filter.

Whenever you have just a funky leaf or two but the rest of the plant is fine it's almost never something to worry about. You can sometimes see damage like that when one leaf is drooped over another for a while. The moisture from the top leaf gets trapped between the two and that brown spotting shows up on the bottom leaf. I call it "leaf sweat burn". Same thing happens when plants get sprayed with water under intense lights and you're not the first newer grower I've run into that freaks out a bit when they first run into it.

I bought some GSC at a dispensary in BC a year ago and tho it was nice I wouldn't have bought more. Just seemed to me to be another one of the many nondescript hybrids that are everywhere these days. Had little effect on what ails me and I want pot that dulls my pain while lifting my mood. A 2:1, CBD/THC pot works best made into cocobudder for me. The buzz is almost like being tipsy on booze and makes me grin so hard my cheeks hurt sometimes.

Your GSC could be just the ticket for you tho and a totally different phenotype than what I got. That's one of the main problems with pot. The same thing can work so well for one and leave the next person cold.

Your plants are looking pretty good. Huge file sizes and took a while to view the pics but looking nice.

Xexmey said:

Checked on them at lights on and saw # 1 drooping quite a bit, # 2 showing a slight droop. Been almost a week since I've watered so I fed them both and waited an hour so you didn't see any sad hungry plants. Forgot I had a water purifier on the sink, came out around 6.3 so much better then without. After an hour they looked much happier and I really couldn't find too many other leaves affected by the spots, just the one leaf. This will be the official first week of flowering and wow, they really do take off. GSC clones if you are curious.

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You pictures are nice but they are slow to load.
Note where it says file size next to the second picture, it says 5.9M
Not sure how best to do it in your case but try to eventually figure out how to get it down to 1M, some computers will have issues opening them. No quality is lost with 1M pictures from what I have seen.

It's one of those PUR deals you attach to the faucet. Maybe the city is doing something with the water, 2 weeks ago it came out that high ( around 8 , 3 weeks ago it was low 7. Didn't even need to pH down this time. The effected plant also is the one I seem to always catch looking underwatered so it has been quite droopy at waterings. Always perks up right after though. Hah, I'll try and downsize the photos next time.

Xexmey said:

It's one of those PUR deals you attach to the faucet. Maybe the city is doing something with the water, 2 weeks ago it came out that high ( around 8 , 3 weeks ago it was low 7. Didn't even need to pH down this time. The effected plant also is the one I seem to always catch looking underwatered so it has been quite droopy at waterings. Always perks up right after though. Hah, I'll try and downsize the photos next time.

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City water is always kept above pH7 and if the feed water is lower than that they add something like calcium carbonate to it to raise it above 7 to prevent corrosion of the metal parts in their infrastructure. Remember what happened in Flint Michigan with the lead poisonings? That was because they switched water sources to save money and started using lower pH water that removed the protective coating that builds up inside the underground pipes and started leaching metals from the old cast iron pipes that have a lot of lead and other heavy metals in the iron.

Have you calibrated your pH pen lately or put fresh batteries in it? If the batteries get low the pH readings can be all over the place. Those PUR filters just remove things like lead and stinky molecules that make the water taste bad. Not made to do anything to the pH.