Hello again. So I am at my wits end with my soil PH and not sure what is going on or what I’m doing wrong. Here’s the info. Growing indoors, 3X3 Vivosun Tent, Mars Hydro Ts-1000, 5 Gallon Fabric Pot, Running 18-6 light cycle. Strain is GSC-E which I bought from here. Growing in Natures Care Organic Soil with 30% Perlite feeding only with GH Maxibloom every day to 20% run-off. (Bill Ward Growing and Feeding Method/Schedule)
I am using tap water that comes from the tap at close to 7.7. Before feeding I mix the recommended 1 and1/3 tsp of Maxibloom per gallon of water and stir till all dissolved. I then PH my water to what I had originally been doing to 6.2 before watering. At the beginning of Week 6 I decided to test my run-off just to see and I was shocked to see it was PH of 7.5. I immediately began flushing the plant with just water PH to 5.8 to try to get my run-off down and after running 6 gallons through the plant at PH between 5.6 and 5.8 my run-off PH is STILL coming out at 7.1 or 7.2. If I understand correctly my soil PH should not be above 6.8 and I don’t know what to do to get it down below that. Should I feed on an even much lower PH going in like 5.0 or even in the 4’s to try to get it down or would that be more hurtful to the plant than helpful?
Also if I’m constantly putting in daily at 5.8 but the runoff is continually coming out at 7.1 what is causing such a big jump from going in PH to coming out PH?
I don’t know anything about that soil…That said, there are soils that are formulated for cannabis. pH is a major factor and when you have the wrong soil you can spend your entire grow chasing pH problems. I did this on my first grow and learned my lesson.
I am not saying that your soil is not going to work for you, just that it will take a lot more effort and likely result in plant nutrient issues that must be corrected.
After that first grow, all I have used is Fox Farms Ocean Forest. This may not be the best soil but it is a good soil. It costs a bit more than other soils but I know what to expect from it and have had good results with it.
Other more experienced growers will likely have more useful advice for you. @Covertgrower@MattyBear@Holmes might have some thoughts.
Yes I agree and this is the last plant I will do in soil. I currently have a few new plants just starting into veg that I’m now growing in Pro-Mix HP CC which hopefully will give me much better and less stressful results.
Not saying you’re doing anything wrong there, because you did some extensive things to fix the issue.
What do the plants look like though? Do they seem upset? Deficiencies?
Only reason I’m asking is, some plants prefer higher or lower ph especially if everything still looks good physically with the plant. Pictures help.
Sadly it’s not fixed because my run-off is STILL 7.1 to 7.2. I’m not showing and signs of problems I don’t think but the last 2 GSC-E I just harvested I had major problems with nute lockout and stunting so I’m trying hard to avoid that this time. Here are some photos…
I think your issue is less the runoff ph as it is you’re feeding at a ph that is out of range to correct something that may not be an issue. The buffers in the soil are going to do what they do. Feed them at 6.5. Trying to correct the runoff ph is likely where your problems are stemming. The last few grows I’ve ignored the runoff ph. One soil ran at 7.1 and the one currently is running at 5.8. I just left that alone and fed at 6.5. No issues.
I concur with all the above! Sometimes we chase after the #s we want in runoff and in most cases all we need to worry about is #s going in, as @BobbyDigital said the buffering in some soils is what it is and we can not change it! Plant looks good=no issue= no correction needed.
Ok so as I feared the same issues have now started with this current Girl Scout Cookies Extreme plant. The new leaves at top of plant are getting those same brown rust spots (not rust)…looks just like Calcium deficiency but there’s Calcium in my tap water AND I’ve been adding a bit of Cal-Mag as well. It’s DEFINITELY the water PH. I ran another 5 gallons of plain water PH to 4.5 and the run-off PH was STILL coming out at 7.1. I then added another gallon of water PH to 3.2 and the run-off FINALLY dropped to 6.8. I then mixed another gallon of water, added my Maxibloom, Cal-Mag, and Molasses…PH to 3.2 again and fed the plant that. This can’t be right. Why and how is my water PH changing so drastically from the time it enters the soil vs when it comes out seconds later??? Makes no sense. At this point I’m guessing I should just keep feeding my plant at a PH of 3.0 in order to get it in target range for the plant to absorb. I just don’t understand why this exact same issue has happened twice now with these Girl Scout Cookies Extreme plants and it happens right around the same time which is right at the 50-55 day from seed mark.
