Hi Gardeners - ive been experiencing some high ph issues within my soil ive done some soil tests and they are coming back at between 7.6-8.2 PH i noticed this 5 weeks into flower when the plants started showing signs. the plants have now finished however, i like to reuse the soil over and over with some added dry amendments i question is, what can i use to LOWER the ph within the soil? thank you all <3
You can use sulfur but it’ll take months. Iron sulfate takes about 2 months. Or you can add peat moss without any lime, crab shell, etc. wait a week and re-test. Water source is usually the culprit. A water report would be helpful to rule this out. RD
Thank you appreciate this. I will get some sulfur and leave these no till pots in the garage till spring then and use for my outdoor grow. Unfortunately stupidly I had been using tap water with a pH of 7.6 and realised my mistake 5 weeks Into flower, since then I been using 5.5 ph to bring it back down, however the plants have finished now and let's just say I'm leaving organics for outdoors in future and will continue on the coco runs Indoors. Cheers mate for the reply much appreciated
My water has an even higher pH but it’s ok to use because the alkalinity and hardness are low enough. Have you checked the pH of your mix? A water report is still helpful and can be compared to university guidelines. Sulfur should be used carefully a little goes a long way. 1tbs (finely ground) per 1 cf will drop the pH a whole point. I would leave the containers outside exposed to natural precipitation over the winter - it helps quite a bit all by itself. RD
1 Tbsp cannot always drop a whole point per cubic foot. The scale is logarithmic. To go from 10 to 9 will require 10x the amount of OH- ions required to move from 9 to 8.
I feel like adding a little acid to a high-hardness water would push your langelier saturation index point down to where scale is less likely to accumulate. In fact, I ran a bunch of expensive water purification equipment in a high hardness area and am certain that is how it is. Most antiscalent products are just an acid. Consistently pouring in hard water will of course raise hell sooner or later.
Ok, I’ll give you that one. I should not have generalized that statement. Factors like the amount of carbonate, CEC and the presence (or lack of) specific bacteria that convert sulfur to sulfuric acid also play a role. A bigger boo-boo I made was I didn’t mention that this is a dangerous game to play in containers and is more suited to raised beds and outdoor environments. Most problems I’ve seen with a high pH do not exceed past 7.5pH since this is roughly when problems occur (iron deficiency). If the starting pH of your mix is 10pH - I would suggest moving or creating a new mix entirely. RD