Soil runoff @ pH 5.0!? How did this happen so fast?

[lampost]

OK, well I found out what the cause of my problems were. I posted about some curling/canoeing leaves and some brown/rust spots I was starting to see on a few plants. I decided to flush and the initial runoff was pH 5.0! I was using distilled water to flush (pH 8.0) and then switched to pH'd tap water (pH 7.1).

Anyway, I flushed the 5 gal container with about 4-5 gal. I ran out of time in the light cycle or I would've flushed more. But I only got the pH of the soil runoff up to about 5.4 after the flush. So, I'll probably need to flush again when it dries out.

So, how did my soil get this acidic so fast? I'm using Fox Farms Ocean Forest cut with a small amount of perlite (10-20%). I also added some powdered agricultural/dolomite lime although the dose was negligible. I used like 5-6 tablespoons for an entire bag of FFOF, so not very much. This plant is only 5 weeks old (from clone). It spent it's first 4 weeks in a 1-2gal container and was just transferred 1 week ago into a 5 gal container with fresh FFOF. So, how did it get this acidic this fast!? I water with pH'd water usually around 6.8. I did initially water with lower pH (maybe 6.0-6.3), but that was only for a week awhile back. I've only fed nutes once (Humboldt Nutrients) and the solution was pH 7.0 and only like 300-400ppm.

I think FFOF just sucks... Am I going to be battling low pH now throughout the remainder of the flowering cycle? What should I do to combat it? Should I water with like pH 7.0 water? Higher?

Peace:rastasmoke:

lampost Reviewed by lampost on 02-20-2010. Soil runoff @ pH 5.0!? How did this happen so fast? OK, well I found out what the cause of my problems were. I posted about some curling/canoeing leaves and some brown/rust spots I was starting to see on a few plants. I decided to flush and the initial runoff was pH 5.0! I was using distilled water to flush (pH 8.0) and then switched to pH'd tap water (pH 7.1). Anyway, I flushed the 5 gal container with about 4-5 gal. I ran out of time in the light cycle or I would've flushed more. But I only got the pH of the soil runoff up to about 5.4 Rating: 5

[lampost]

Well, as I watered some other plants today I noticed that the other plants are also having low pH runoff. One of the White Widows was at 5.1, but it's not showing any of the canoeing or brown spots. The Sour Diesel and the Headband are the ones that are affected by this low pH. I'm thinking nutrient burn also contributed... so it probably wasn't only pH.

[EvilCartman]

Take a breath.

Did you check the ppm of the runoff?

Fresh FFOF _will_ give you very low runoff pH. If you've only been in the 5 gallon for a week, chasing pH runoff is going to result in disaster.

I nearly freaked the first time I checked, it was also in the area of 5 out (in @ 7). Seemed impossible, so I did a soil test. Soil tests pegged it at 6.5. The FFOF is buffered pretty well, adding a little additional lime should have helped to stabilize it even more.

I honestly doubt there is a real soil pH problem, other than variation of the water going in. Keep it ~6.8 with the FFOF.

Don't panic too much if they start looking worse, before looking better. Slugging them hard with that 8.0 stuff may piss 'em off.

[WashougalWonder]

I doubt very seriously it was the Fox Farms Ocean Forest. Why did you add dolomite and perlite? That stuff is perfectly balanced.

Most references show PH of most distilled water to be on the acidic side, so I question the reading of 8.0 or that the water is distilled.

You, by adding stuff to the soil, messed with/flushed out the buffers they put in. Dang it, I cannot get it through to you that you are killing with kindness.:hippy:

Seriously, man I just use ffof and RO water, but PH stays in the 6-7 range on the water. I don't water enough to get runoff until late in the flower cycle. The only fertilizer I recommend is a TINY bit of 16-16-16 slow release at the beginning of the flower cycle. (I am experimenting still, but best results are as stated.)

FFOF has enough good stuff in it to get 6 weeks of awesome growth before needing to supplement nutes....if you don't wash them all out.

Just transplant them to fresh soil. My plants in 3 gallon containers, under a 1000, 3-4' tall use about a quart of water a day in flower. If I over water and flush out the buffers and salts, then everything I put in has to be in balance.

By not watering so much it does not wash out the pots, and by not adding more salts (RO water controls that, but it is not distilled), or fertilizers (salts) the balance stays the same, the plant has a great root environment, and the plant stays healthy. The most I have seen as far as nute disorder on FFOF is K, but that could be because of the 16-16-16.

Want to test it? Pick two plants at seedling stage that are similar in growth and size. Just one treat the way I suggest. Do all the fun stuff to the others. This will be a boring plant, until about week 4 in flower.

This actually is what I consider advanced growing, because you have to chill and let them stay pretty dry. Lots of sips of water so it soaks in, not runs through.

[lampost]

Take a breath.

Did you check the ppm of the runoff?

Fresh FFOF _will_ give you very low runoff pH. If you've only been in the 5 gallon for a week, chasing pH runoff is going to result in disaster.

I nearly freaked the first time I checked, it was also in the area of 5 out (in @ 7). Seemed impossible, so I did a soil test. Soil tests pegged it at 6.5. The FFOF is buffered pretty well, adding a little additional lime should have helped to stabilize it even more.

I honestly doubt there is a real soil pH problem, other than variation of the water going in. Keep it ~6.8 with the FFOF.

Don't panic too much if they start looking worse, before looking better. Slugging them hard with that 8.0 stuff may piss 'em off.

Yeah, I've noticed this about the FFOF. Almost all of my plants have a runoff in the mid-5's pH-wise. But all the older, larger plants look great.
I don't know exactly what was causing my problems but I think it was probably over-fertilized. The plants that were showing these symptoms were 1 week younger than the large plants (which loved the nutrients)... but these younger plants were a lot smaller and probably couldn't take it.

Thanks for the reassurance. I'm glad I didn't do a serious flush. I flushed the other younger plants only about 2-3 gallons through a 5-gallon. So, hopefully I should have some buffers and nutrients remaining in there.

[lampost]

I doubt very seriously it was the Fox Farms Ocean Forest. Why did you add dolomite and perlite? That stuff is perfectly balanced.

Most references show PH of most distilled water to be on the acidic side, so I question the reading of 8.0 or that the water is distilled.

You, by adding stuff to the soil, messed with/flushed out the buffers they put in. Dang it, I cannot get it through to you that you are killing with kindness.:hippy:

Seriously, man I just use ffof and RO water, but PH stays in the 6-7 range on the water. I don't water enough to get runoff until late in the flower cycle. The only fertilizer I recommend is a TINY bit of 16-16-16 slow release at the beginning of the flower cycle. (I am experimenting still, but best results are as stated.)

FFOF has enough good stuff in it to get 6 weeks of awesome growth before needing to supplement nutes....if you don't wash them all out.

Just transplant them to fresh soil. My plants in 3 gallon containers, under a 1000, 3-4' tall use about a quart of water a day in flower. If I over water and flush out the buffers and salts, then everything I put in has to be in balance.

By not watering so much it does not wash out the pots, and by not adding more salts (RO water controls that, but it is not distilled), or fertilizers (salts) the balance stays the same, the plant has a great root environment, and the plant stays healthy. The most I have seen as far as nute disorder on FFOF is K, but that could be because of the 16-16-16.

Want to test it? Pick two plants at seedling stage that are similar in growth and size. Just one treat the way I suggest. Do all the fun stuff to the others. This will be a boring plant, until about week 4 in flower.

This actually is what I consider advanced growing, because you have to chill and let them stay pretty dry. Lots of sips of water so it soaks in, not runs through.

I question that distilled water too... got it from the supermarket. But my pH meter was calibrated and it's a good pH meter.

My plants actually look really good. I'm not killing them with kindness. I never water like this. I usually water until I see a few drops come out the bottom and I do it slowly, so that's all that comes out! I let my plants dry out pretty well too.

The majority of my plants are doing excellent, but these fuckin' Sour Diesels are driving me nuts!! They're very sensitive and they were having some sort of problem. The semi-flush actually helped, so I'm glad that I did it.

Now I'll let them dry out and get back to normal. But I wanted to nip this in the bud... I've heard these fuckers will herm pretty easily... so I have been paying extra attention to them.

[WashougalWonder]

Well pay that extra attention more visually than actual doing stuff. You are going to give yourself an ulcer dude. LOL You are too funny

[Rusty Trichome]

Doubtful your ph numbers are accurate. FFOF is properly buffered near 6.5 to 7.0 ph, I believe. That's where it should stay for a couple of months till the buffers fade.

What are you using to check runoff ph? If it's a color-coded result, (freshwater aquarium ph test kit, ph test strips...) the tinting of the runoff will skew results.

If using a ph pen, it likely needs calibrating.

Or, you are re-using soil.

Or, they forgot the buffers in that one bag of mix.

[EvilCartman]

I question that distilled water too... got it from the supermarket. But my pH meter was calibrated and it's a good pH meter

I've noticed a lot of the distilled carried in supermarkets is adjusted up. Probably so it's more suitable for mixing baby formula and stuff. Don't wanna give Junior heartburn.

[WashougalWonder]

I've noticed a lot of the distilled carried in supermarkets is adjusted up. Probably so it's more suitable for mixing baby formula and stuff. Don't wanna give Junior heartburn.

In researching the PH, I learned that true pure distilled water has PH of 6-7, but it rises as it absorbs carbon dioxide from the atmosphere

Pretty cool huh:jointsmile: