Okay so this is my main area of struggle when it comes to growing. I know pHing water or nutrients seems simple but I messed up… I use RO water from Walmart ( I make sure its RO not distilled or spring water, RO only) and usually that water comes at about 5.5 pH. I used to use the distilled water bottles last grow before I knew that RO is the way to go but it also came at a 5.5 pH roughly. When I’d use either water in compost tea, the pH would generally end up right at 7.0. At some point this grow, my water was too alkaline and my runoff measured at 7.5. I’ve been pHing right at 6.8 the whole time except once or twice I just used pure water and didnt pH. I’m wondering how I can bring my pH back down so my runoff measures more in the range of 6.5 rather than >7?
I used dolomite lime in my soil mix (prior to planting) to try and help stabilize pH if that helps. I have “flushed” with 6.0 pH water after I got the initial readout of 7.5 on runoff but still got 7.6 after??? Also using Apera instruments pH tester and I calibrated and got the same readouts.
First, RO and Distilled are pretty much the same thing, just made with a different process. Both should be 0 PPM. This makes reading the pH quite difficult with an electronic meter.
Second, you’re doing organic soil. Really, you don’t need to pH anything. The plant has the ability to exude sugars to attract specific bacteria to adjust the pH.
I have this issue when using peat-perlite blends(soil-less) and it’s very frustrating… & may try a mix with charcoal as a buffer & hopefully an acidifier. Perlite is neutral & then salts hang around & the peat can’t lower the pH enough. In the past I’ve experimented with orchid media & had mostly poor results but it seems ideal to this “scientist”.
Espoma soil acidifer works but very slow for (our) purposes. The sulfur is also helpful IMO.
@ReikoX I am not seeing problems on leaves or funny smell like I have in the past. This is solely based on the pH reading from runoff after running 3 gal of 6.0 pH water through 10 gal pot. I was really just confused how the pH went up to 7.5-7.6 when what I’m putting in is pH’d so much lower.
Most likely the dolomite lime is raising the pH. RO water has little buffer, so it is easy to swing the pH. But again, organic soil the pH is controlled by the plant.
To your point about being easy to swing the ph in RO water- should you add something to RO water like a tsp of Epsom to get some dissolved salts in the water then check ph and adjust?
I use bottled RO on my seedlings and solo veg cups, but dont adjust ph at all. Just add ferts straight to it and go. The starting ph w what ive bought has always been close to 6 so no need to change in my mind and seems to work.
@cannabissequoia strangely enough, my mix this time around is basically this:
Roughly 4gal base of ocean forest
Perlite
Worm castings
Lobster compost
Biochar
Dr Earth organic veg & flower dry amendments
Azomite
And mycorrhizae
The charcoal is there. Maybe I should go pHless for the rest of this grow and see how it works for me. Only RO water and compost tea.
@ReikoX Very insightful, thank you for your input. I think you answered my question and I will go with no pH buffers for the rest of the grow and see what happens
Ph’ing water that’s damn near 7 ph will have wide swings either up or down we have to remember that a ph of 6 is 10 times more acidic than 7.0 if your in soil I’d not worry about phing RO water, your normal tap should be in most cases should be alright save your self some $ and not use Ro or distilled when watering plants
So what do you do w really hard water w high TDS, that runs thru a softener? Really hard to manage plants in veg in small pots w the starting tds that high before I add any nutrition. And organic soil w just amendments doesnt seem like it’ll work w pots under a gal.
If you can set up a rain barrel, that’s all I use now and its always perfect ph never have problems. Growing organic i always try to keep water going into the plant 6.5-7ph if using town water let it sit out for a few days in a 5 gallon bucket and adjust ph if needed.
I use small pots (under a gallon) all the time in veg with organic soil, only water and the odd compost tea. don’t seem to have a problem with that just stay on top oh the ph of the water going in.
Glad you mention a softener do you know if the water system polishes the water again to knock out the NACL? Iv heard that these can really wreck havoc on plants if that’s not the case … most if not all outside taps are not hooked up to water systems which may be the route to take I’d hate to recommend boiling large amounts to help knock out the TDS either that or dilute your water 50/50 with RI and try that
I have a Newer water system and the water that’s turning into the RO tank also has an alkalinity filter also which bumps the ph up also is your system have such a thing?
I grow in organic soil outdoors. Only time I had problems was when I tried ro water and actually messed with the ph. I use tap water that sits overnight and never have to mess with cal mag or ph up or down and my tap water is like 5.5. Zero problems when I go simple.
My municipal water is 8.1 from tap and has chloramine, not the greatest source for organics. Crazy to see how different townships regulate their water so differently
and has chloramine, not the greatest source for organics. Crazy to see how different townships regulate their water so differently
