Hey my bad fellas I've been working a lot and just now got some time. The ph of the water I out in its around 6.3 but the run off seems to be significantly lower so I'm starting to assume it's a ph lockout problem.
1. You can foliar feed to keep the plants going while correcting the soil ph. Something like 1/4 strength all-purpose fertilizer. Or, 1/4 strength Alaska Fish Emulsion, + 1/4 strength Alaska Morebloom, + 1/2 strength Alaska Kelp. (I'm not a fan of these nutes. But, they're cheap. I had some and used them for foliar feeding when I faced a surprise acidic soil.). You can also foliar feed a CalMag product (say, a rate of 2.5ml/gal), or Epsom Salt alone (say at a rate 1 tsp/gal).
You don't have to sweat the details. When the plant's been locked out as long as yours has, it will respond to these things. You can mix them up every day.
Be warned,
- The fish smells bad. It will linger for awhile.
- Keep plants out of strong light. The water drops will focus the light and burn the leaves.
- If you're in bloom, you have to weigh your humidity and risk of bud rot. Perhaps use fans to accelerate drying.
2. To correct your soil ph. None of this is fast acting:
- Water/feed at about 7.2. After a few feedings the soil PH will pull higher.
- Cultivate 1tsp (per gallon of container size) dolomite lime into the top soil. Use a fork to rake it in, but try not to damage the roots. Do this after each watering until you've cultivated 1Tbsp/gal.
Be sure to use dolomite lime (also called Agricultural lime). Don't do this with hydrated lime (also called horticultural lime). Use the finest powder you can find. If it's not like flour, mash it in a bowl using the rounded end of a screwdriver handle. The finer the better.
It takes 10-14 days to see an effect.
For more immediate effect, use hydrated lime. About 1tsp/gal of water. The ph will be about 11.2. Pour it into the container to saturate, but not get runoff (you don't need runoff, just saturation). Let it set and impart it's ph upon the soil, then feed with 7.2 nutrients, displacing the hydrated lime water (although some lime will remain).
This is also a bit of a mini flush. If you have a 3-gal container, do 1 gal of the hydrated lime. Then water with 1 gal of nutes (at ph 7.2). You'll get about 70% runoff, which is significant. Not as stressful as 3x flushing. But, significant.
Be careful with hydrated lime. It's strong and phytotoxic. You don't want to overuse it.
I use an organic'ish nutrient which acidifies the soil. I've learned the timing of this acidification and can easily control it using 7.2 feedings and a couple 11.2 (hydrated lime) soaks. I may start amending some into my soil before planting. Like, 1/4 tsp / gal of soil. I amend 2 Tbsp /gal *dolomite* lime into my soil. But, it doesn't stop the acidication.
3. Buy a Control Wizard Accurate 8 soil ph probe. About $50.
This is really useful to monitor your soil ph. Burnish the probe's metal using the souring pad it comes with (or 0000 steel wool), and let the probe remain in the soil 10 minutes.
You an use this to assess your runoff measurements. I don't find runoff to be too accurate. (I don't think those soil probes are either.). The longer the water remains in the container before being displaced as runoff, the more it equalizes to the soil. If you get quick runoff, the soil ph may be much lower than the runoff. If you saturate the soil, wait 30 minutes, then displace it with additional water, the ph of that runoff will be closer to the soil's ph. Anyway, I find the probe helps confirm the runoff, and vice versa.
Don't get frustrated. This is an opportunity to learn the benefits of foliar feeding. And, going into your next grow, you'll be better prepared to detect ph problems and correct them sooner (either higher-ph waterings, or a more drastic hydrated lime soak.).
When I went through my surprise acidification I thought I didn't know how to grow. Very disappointing. But, in the end, I learned a lot. Here's the plant two weeks before harvest:
Don't give up. Even if it doesn't work out for you, the worst that will happen is you'll learn a lot.
