Hey guys, I have 3 plants who's PH runoff has been consistently too high for awhile now. I've adjusted my water down to as low as 5.5ph and my runoff is coming out at about 7.1ph. I'm using Fox Farms Ocean Forest potting soil with about 25% perlite. I've noticed the 2 smaller guys (who are much younger than the big one thats in flowering) have gotten a slight amount of nute burn, so I've backed off the nutes altogether on them. I guess my question is, if I'm consistently watering my plants with 5.5ph water and getting 6.9-7.1ph runoff, should I lower the PH of my H20 or nute solution(for my bigger guy) to try to drop the PH even more? I don't think I completely understand how to manage the PH of my plants, even after reading A LOT of articles. Any advice would be much appreciated.
PH Runoff too high and wont come down
- Thread starter Byd3s1gn
- Start date
scroglodyte
Well-Known Member
soil buffers water, not the other way around. 7.1 is on the border of alkaline for cannabis, but won't give you lock-out, imo. add some sulfur to the soil and water it in. sulfur is to acid, what lime is to alkaline.
nick17gar
Well-Known Member
well your in soil so you should be aiming for 6.8
if the runoff is coming off higher then that, then flushing with plain water might be a good idea. then water with 6.5 pH or so. whats the plant look like? id imagine your soil is high on P or K, which are basic (7-14 on the pH scale). you can also try upping the nitrogen (which is acidic). dolomitic lime is also good for buffering the soil and keeping peaks away
if the runoff is coming off higher then that, then flushing with plain water might be a good idea. then water with 6.5 pH or so. whats the plant look like? id imagine your soil is high on P or K, which are basic (7-14 on the pH scale). you can also try upping the nitrogen (which is acidic). dolomitic lime is also good for buffering the soil and keeping peaks away
The plants aren't looking bad at all, but they aren't growing quite as fast as I'd expect. Also, the edges of some of my lower leaves are yellowing/browning due to giving too much nutrients earlier this week (I think.) I actually did flush both of the plants last night with 5.5 ph water trying to get the ph to come down a bit, but after over a gallon and half each, my last run off ph was still about 7.1. When I tried flushing them with a more neutral ph water (like 6.5), my runoff came out at over 8!! So should I stick with watering them with 5.5ph water? 'm using fox farms nutrients, so I don't think I can give my plants just nitrogen (without other nutrients as well.) I knew I should have put some dolomitic lime in my soil... I just couldn't find any locally when it came potting time. One more question, when I put these guys in bigger pots (they are in 3/4 gallon pots), and I use fox farms ocean forest potting mix, do I need to wait 3 weeks before starting any nutrients (every time i repot?) since the soil already has nutes? I really appreciate yalls help guys. Stick with 5.5ph water (giving me 7.1ph runoff) or go up to 6.5 (giving me 8ph runoff?) Thanks!!
90cody
Active Member
how big are these pots ??
the bigger the pot ( the more the soil) the more water that is required to flush obviously..
but IMO the more buffering capability , meaning the more it will fight dramatic pH changes.
exactly how long have u been testing ur run off with a 5.5 pH
also, what are u using to modify ur tap water to an exact 5.5pH (which type of UP or DOWN) or some other method?
the bigger the pot ( the more the soil) the more water that is required to flush obviously..
but IMO the more buffering capability , meaning the more it will fight dramatic pH changes.
exactly how long have u been testing ur run off with a 5.5 pH
also, what are u using to modify ur tap water to an exact 5.5pH (which type of UP or DOWN) or some other method?
lahadaextranjera
Well-Known Member
Check the final flush , not the first few buckets