PH related lockout, am I on the right track?

Hi Everyone,

I am just starting week 6 after fighting a PH issue over the weekend. I am using Future Harvest Holland's secret (full line, inherited from buddy, trying it out), DTW in Coco, 7 gallon plastic nursery pots. (I plan to use smaller pots or air/fabric pots next time, but chose these as I thought 7gal plastic would give me a longer dry time and I am going away for one weekend around week 7 or 8 and wanted my plant sitter to only have to water once).

Method:
- I follow the future harvest schedule of plain ph water ever 3rd feeding.
- My tap water is low PPM and ph 6.9 to 7. I let the water sit to de-chlorinate, and then mix to full strength and ph to 5.8. (likely big mistake #1)
- I hand water to run-off twice a day at lights on, and as close to 5 hours before lights off as I can get to help my overnight humidity. That means my schedule is something like: Monday: Feed, Feed. Tuesday: Water, Feed. Wednesday: Feed, Water, Thursday: Feed Feed, Friday: Water Feed, etc.

Mistakes I think/know I made:
- Using full strength nutes without an EC/TDS meter likely put me at or over the max EC, I need to leave a lot of breathing room I think since I don't have a meter.
- I likely wasn't getting ENOUGH run-off, even though I made sure I was getting run off after an even saturation of the medium, I probably need more than a trickle.
- I was checking run off PH all the time, and it never moved early on. I got lazy and made assumptions that I was doing such an awesome job I didn't need to anymore to save time.

My assumption/Diagnosis:
- A combination of over feeding, under watering, large pots, and not checking run off lead to a build up of salt and subsequent crash of ph.

Remediation:
- Day 1 Evening (Water): Noticed PH dive. Immediately a started flushing with PH'd plain water from one of my 5 gallon pails, this took too long and wasn't nearly enough, lights turned off. I don't have a green lamp yet.

- Day 2: Morning (Feed): I flush a bit to get some run off before feeding and see where PH is. It's still way low. I hook up the hose to my tap water and start flushing with chlorinated ph7 water. I get it close to 6.1 as I can. Then I gave it a half strength feed at 6.0. Run off seems ok-ish.

- Day 2: Afternoon (Feed): Time for another light feed, but I want to take it easy. I try a small flush again just to check, and the PH has dropped again. I suspect that as I am flushing, it is clearing out the immediate build up and running clean, but then when it sits for a while, it is leaching more and more built up salts from the perlite and dropping the PH again. I flush again with chlorinated ph7 tap water. Wait, and then flush again a little later. Finally reach PH 6.2.

- Day 3: Morning (Water): Run off still stable around 6.2.
- Day 3: Afternoon (Feed), small flush to get run-off, still 6.1-6.2, Light ph6.0 feed. Run off still 6.1.

- Today, day 4 morning (Feed): Just went for a 6.0 3.4 strength feed. Runoff showing 6.1. Sick plants seems to have new pistil growth.

Plan Going Forward:
- Continue 3/4 strength feedings at regular schedule with more run-off, resume regular monitoring run off.

My questions:
- Have I performed any steps that have increased my potential for further problems?
- Am I planning the correct steps for a return to health?

Thank for reading and any advice or confirmation of the steps I have taken!

Pics added for fun, I know to use regular lighting if I expect help based on pics. I have 3 synthetic plants on the left, and 4 more in dry organic amendments on the right off camera.

Update from afternoon plain watering interval just now.

Ran approximately 1.25gal ph 6.0 into each pot, observed runoff at 5.4 to 5.6. This feels too low to just be the result of normal feeding activity and is a large drop from where I left it around 6.0 to 6.1. earlier. I don't think these plants are diseased otherwise, so wonder if this is still salt build up leeching over time.

To correct, I ran another 1.25gal of (not completely) de-chlorinated tap water at ph7 through the pots, waited for the runoff to turn to a slow drip, and collected the drippings separately. They read 5.5 at low end, and 5.6/5.7 for the other 2.

I think I should adjust my plan slightly:
- For feed intervals in my schedukle I will adjust the ph to 6.2 and observe run-off.
- For water intervals, while ph is still low, I will water with ph 7 water to help flush and bring up the ph.

as the ph rises, I will adjust both downward to eventually arrive at 5.8 again, and try to hold.

Should I be concerned that the up and down swing from feed at 6.2 to water at 7.0 is too large? should my plain water be closer to 6.2 as well even though run-off is coming out too low?

Thanks!

A few pointers...

Stop using plain water...regardless of what you're reading from your nutrient line, plain water in a coco grow is no bueno. If the idea is to minimize salt build up, ratchet back your feed %, but don't feed plain water.

Secondly, pH your feed to 5.8, and go....ideally it's not bad to let the pH swing up slightly, but in my experience anything over 6.1 begins to cause issues. Rather than mix up a batch of feed at 5.8, then one at 5.9, etc, to get a full pH spectrum, just make up more feed than you use in a day, start it at a pH of 5.8, then the next day it will most likely have climbed some, etc, etc. Once the pH is too high, use the remainder in your garden outside and mix more and start again.

You can reset your medium by simply mixing up enough feed at 5.8 and at your desired EC / PPM, and then pouring it through your plant until you get copious amounts of run off. 7 gallon pots will require quite a bit of run off, so don't think just because half a gallon of run off came out of the plant, it's all ok. When what's coming out of the plant is 5.8 pH and at your EC/PPM, you're done.

I can't tell much from your pics, because of the yellow light, but from what I can see, they look pretty good, so don't go knee jerking your way into issues.

Thanks @CannaCountry I knew the pics wouldn't help. Planning to take regular lighting pics at lights off when I don't have to turn off the hps just to snap pics.

I should say, I am trying to rebound this medium from 4.8-5.0ph back to 5.8, it was extremely low due to me not following my own rules to never get lazy and never make assumptions.

As of just now (the last plain water of the day @ 6.5ph for corrective measure, and the last ever for the rest of the grow), I collected a new batch of run-off from the slow drip they are still doing. At almost 3 gallons per pot @ 6.5ph, the runoff ended with a value of 5.5, 5.6 and 5.7 for the 3 plants respectively.

Can I confirm that even with ph in of 6.5 and out of 5.5 to 5.7 you would still only use ph5.8 water? I have every intention of returning to using 5.8ph feed consistantly, but worried that while the ph is unstable, 5.8 would cause it to drop too low still. I trust your judgement, but wanted to make sure I communicated my concern clearly.

Thanks for your time! Proper pics to come in about an hour or two.

Relic79 said:

Thanks @CannaCountry I knew the pics wouldn't help. Planning to take regular lighting pics at lights off when I don't have to turn off the hps just to snap pics.

I should say, I am trying to rebound this medium from 4.8-5.0ph back to 5.8, it was extremely low due to me not following my own rules to never get lazy and never make assumptions.

As of just now (the last plain water of the day @ 6.5ph for corrective measure, and the last ever for the rest of the grow), I collected a new batch of run-off from the slow drip they are still doing. At almost 3 gallons per pot @ 6.5ph, the runoff ended with a value of 5.5, 5.6 and 5.7 for the 3 plants respectively.

Can I confirm that even with ph in of 6.5 and out of 5.5 to 5.7 you would still only use ph5.8 water? I have every intention of returning to using 5.8ph feed consistantly, but worried that while the ph is unstable, 5.8 would cause it to drop too low still. I trust your judgement, but wanted to make sure I communicated my concern clearly.

Thanks for your time! Proper pics to come in about an hour or two.

Click to expand...

Not 5.8 water...but yes pH 5.8 feed. Remember, no plain water. If your input is higher than your output, in terms of pH, it may mean you have a little build up salt wise, but don't panic. Just keep feeding with 5.8 feed, each and every time you feed ( or water if that's what you call it). Frankly I don't check my run off and never have. I simply keep my feed going in from 5.7-6.1, starting at the lower end, letting it swing up naturally (I feed from a reservoir) and then repeat the process. My simple advice would be to be sure you're always going in with 5.8 and you'll be fine. That is not to say though that you won't have to monitor and adjust your EC/PPM...again, I don't bother with those numbers personally, but they are a good metric when you're just starting out. Remember, being that you will feed daily using coco, your feed doesn't have to be extreme, nutrient wise...moderate PPM/EC values will work wonders, simply because you're feeding each and every day. Hope that helps.

Pics from this evening.

You look a little short on K, and perhaps Ca, but you're deep into flower, so don't try and change the world. It may be best for you to take notes and use what you learn from this grow and apply it to your next. I wouldn't go chasing perfect leaves at this point; you're near the end. Looks like you'll have a nice harvest no matter; enjoy.

Thanks. As an aside, I was considering "watering" to be plain pH adjusted tap water, and "feeding" as I used it to mean nutrient solution.

Regardless, I'm done abusing them now. No more extreme flushes, 3/4 strength nutrients for every feed. I am seeing new good looking growth. If the ph starts to drop I'll notice this time and will continue to weaken the nutrient solution and push more solution through each feeding.

I don't really want to have to buy a TDS/EC meter and can already see the freedom a weaker mix will give me. Before I was worrying about being a hair over when measuring out the bottles, now there is breathing room to be off a little.

Thanks again!