Indoor Soil PH Issues; WHY?

[Peekineeze]

Soil Mix: Fox Farm Ocean Forest/Perlite 50/50

This is my first grow and I have had nutrient deficiency issues. Almost all my plants have the same symptoms; rust spots, purple stems and small buds. I understand what I have to do to fix it. I just ordered some pulverized dolomite lime since apparently the Epsoma Garden Lime pellets that I have are too slow acting. What I don't understand is why my soil is doing this. I just tested the runoff water on a hand full of my plants. I watered them with (6.8-7.0) water for the test and the runoff is coming out at (4.0-5.0). One of the plants I tested was only 14 days old and had never been given nutrients. Another was an older plant (49 days) that had just been flushed with tap water (PH>8.0) 3 days prior. The other plants I tested we're on regular nutrient schedules. None of them tested above (5.0). I am using Fox Farm Trio nutrients with the soil mix as stated above. I accidentally bought the hydro formula of Grow Big but from what I understand it's ok to use in soil.

So I am curious as to why my soil won't maintain a reasonable PH. Fox Farm puts buffers in their soil yet my runoff is very low even when no nutrients are added. Im wondering if other OC users have had this problem. Do you always have to add lime to the soil? Any help would be appreciated.

Also, is it better to test the actual soil PH with one of those soil test kits or is checking the runoff water sufficient? Thanks.

 

[Muddy]

Fox Farms has had some quality issues for the past year or so. Apparently they exhausted their original source of materials and were farming it out. There have been others here that have had very low pH is OF, so you're not alone. This has been discussed here at length multiple times. Do a search and you will find a couple threads dedicated to the problems with OF.

 

[Peekineeze]

Thanks

 

[BigBuddha]

50% perlite? Way too much in my opinion and it can have an alkaline effect and/or offset the natural ph balances in the soil in such a quantity.

 

[Peekineeze]

50% perlite? Way too much in my opinion and it can have an alkaline effect and/or offset the natural ph balances in the soil in such a quantity.

I heard autos liked lose airy soil. It does seem like a lot but I've read that a lot of Auto growers use that mix. If the Perlite had an alkaline affect, wouldn't it effect the PH of the runoff water? I was wondering about the Perlite yesterday so i checked the PH of tap water mixed just with Perlite and it didn't change the PH.

 

[Peekineeze]

I've read quite a few posts from people saying that checking the runoff water is a waste of time. I've read others say the soil PH test kits are unreliable also. You guys check runoff PH or soil PH?

 

[BigBuddha]

I heard autos liked lose airy soil. It does seem like a lot but I've read that a lot of Auto growers use that mix. If the Perlite had an alkaline affect, wouldn't it effect the PH of the runoff water? I was wondering about the Perlite yesterday so i checked the PH of tap water mixed just with Perlite and it didn't change the PH.

Hey, Peek. Same here.. when I first started autos I'd read the same and was giving mine up to 40%.. but it tends to be one of those urban-myths from about 30yrs ago, back in the day when potting soil was rubbish and wasn't carefully blended to give optimum air-water ratios like it is these days. Mandala seeds, and I think Big Buddha seeds, are pretty passionate about that issue. It's still useful but most good quality soil has plenty in it. The way I see it is that one of the functions of the soil is to provide organic mater for the bacteria to break down into food, also crucially to help create the right environment for Mychorizza (the root fungus). If there's only half the amount in the medium.. it stands to reason that we're removing half the potential feed and healthy growing environment.

I've done side-by-sides and find that I get far far better result by adding no extra perlite. In fact I'd like less in the biobizz soil I use. In fact I really hate perlite because it's highly toxic.

Sorry.. to answer your question.. yep perlite and vermiculite will affect the runoff ph as will everything else in the pot and annoyingly one tends to affect the other which affect another thing which affects the first thing
No getting around that one. I think largely it's due to the difference in rations between soil/improver, but most good compost is airy enough without extra perlite as that's how it's been designed. For soil grows.. we need the bacteria more than pretty much anything else in the medium and they only like living on the soil.


All that said I'm not saying you're wrong to do it your way as it's your happiness with the results that matter. I was just chiming-in with my tuppence-worth and may have sounded haughty.

I've read quite a few posts from people saying that checking the runoff water is a waste of time. I've read others say the soil PH test kits are unreliable also. You guys check runoff PH or soil PH?

I don't do it personally as it all just seems to unreliable and complicated to me. Bu I can't say it's a waste of time because it can tell a lot about soil conditions. So far as soil ph testers.. unless you buy a specific expensive brand that's meant to be super accurate.. they're all a total waste of time and money.. measuring 6.8 for water that's actually 8.2 is useless for weed growers!

Digi ph ones that are pretty accurate can be found for 15 quid on ebay.

 

[Peekineeze]

Hey, Peek. Same here.. when I first started autos I'd read the same and was giving mine up to 40%.. but it tends to be one of those urban-myths from about 30yrs ago, back in the day when potting soil was rubbish and wasn't carefully blended to give optimum air-water ratios like it is these days. Mandala seeds, and I think Big Buddha seeds, are pretty passionate about that issue. It's still useful but most good quality soil has plenty in it. The way I see it is that one of the functions of the soil is to provide organic mater for the bacteria to break down into food, also crucially to help create the right environment for Mychorizza (the root fungus). If there's only half the amount in the medium.. it stands to reason that we're removing half the potential feed and healthy growing environment.

I've done side-by-sides and find that I get far far better result by adding no extra perlite. In fact I'd like less in the biobizz soil I use. In fact I really hate perlite because it's highly toxic.

Sorry.. to answer your question.. yep perlite and vermiculite will affect the runoff ph as will everything else in the pot and annoyingly one tends to affect the other which affect another thing which affects the first thing
No getting around that one. I think largely it's due to the difference in rations between soil/improver, but most good compost is airy enough without extra perlite as that's how it's been designed. For soil grows.. we need the bacteria more than pretty much anything else in the medium and they only like living on the soil.


All that said I'm not saying you're wrong to do it your way as it's your happiness with the results that matter. I was just chiming-in with my tuppence-worth and may have sounded haughty.





I don't do it personally as it all just seems to unreliable and complicated to me. Bu I can't say it's a waste of time because it can tell a lot about soil conditions. So far as soil ph testers.. unless you buy a specific expensive brand that's meant to be super accurate.. they're all a total waste of time and money.. measuring 6.8 for water that's actually 8.2 is useless for weed growers!

Digi ph ones that are pretty accurate can be found for 15 quid on ebay.

Thanks for the help. I'm going to try less Perlite like you said. I have 2 plants that are ready to be transplanted as soon as I figure out this issue.



"All that said I'm not saying you're wrong to do it your way as it's your happiness with the results that matter. I was just chiming-in with my tuppence-worth and may have sounded haughty."

This is my first grow. I don't have a "my way" yet. Lol.

"I don't do it personally as it all just seems to unreliable and complicated to me. Bu I can't say it's a waste of time because it can tell a lot about soil conditions. So far as soil ph testers.. unless you buy a specific expensive brand that's meant to be super accurate.. they're all a total waste of time and money.. measuring 6.8 for water that's actually 8.2 is useless for weed growers!"

Now I have just about every kind of PH tester available. I have one of those soil probes which is a useless piece of junk. I have the drop water tester, soil test kit, test strips and finally a digi. So I can cross check my results 5 times. Lol.

I just did a soil test with the soil test kit and it came up slightly acidic which is right where Ocean Forest is supposed to be. So I'm wondering how you can take water that is close to 7.0, run it through soil that is around 6.0 and come out with runoff water that is between 4.0-5.0. That doesn't make any sense to me. I hope I can figure this out this week because I have 2 plants that are just beginning to show symptoms and the other two are ready to be transplanted.

 

[BigBuddha]

Hey, Peek. Hmm.. if it's going in 7 and coming out 4-5 the soil's acidic. No two ways about it. As Muddy says this seems a common problem with OF at the moment but they seem to have figured out how to handle it somewhere on the forum so get cracking on that search function.

Personally I'd throw away all but the digi ph tester. Actually I'd burn them first.

I promise you won't be disappointed using less perlite next time.

I'm rooting for you fella and if I can find that thread I'll link you to it.