Another pH Question - Cannabis.com Forums Message Boards - Medical Marijuana, Cannabis Club, Dispensary, News

PharmaCan · #1 (**permalink**) May-17-2007, 13:43

Water comes out of my tap right about pH 8.0. I aerate 5 gals for 1 - 2 days to get rid of any chlorine then add my vegging nutes - A/N 3-part, calmag+ & superthrive. (I add molasses & Sweet just before I feed but I keep those out of the resevoire because they attract small red flies.)

I'm using a pH test kit right now. I ordered an electronic tester a couple days ago and it should arrive today.

After adding the nutes, the pH is usually right around 6.5, which is the pH I've been using with the Coco I'm growing in. Then I feed the girls.

The next morning the pH is back around 7.5. So I add pH down until I reach the desired pH. Then I feed the girls.

The next morning the pH is back up to over 7.0 yada, yada, yada.

I've been feeding the plants as soon as I get the pH to the desired 6.5, but then I also work on the reservoire and wait 1/2 hour, adjust if necessary, wait 1/2 hour... and so on and so forth until it is stabilized - and still the pH is back higher the next day.

What the heck is going on?

Weedhound · #2 (**permalink**) May-17-2007, 14:07

You are growing hydro? If so your ph should be 5.5-6.2.....6.5 is too high. If you are growing in soil its ok.

Weedhound · #3 (**permalink**) May-17-2007, 14:21

I forgot to ask how old your plants are but since you mentioned veg nutes I'm assuming you are not flowering them yet. If they aren't towards the end of blooming (about week 4) the ph should not be rising like that. I have a feeling that your ph is too high to start with and causing some burning or something similiar like lockout which is causing your ph too rise too quickly.

Here's a chart that Zandor posted about ph....hope it helps

http://boards.cannabis.com/attachmen...oill-hydro.jpg

PharmaCan · #4 (**permalink**) May-17-2007, 15:35

Quote:

Originally Posted by Weedhound

I forgot to ask how old your plants are but since you mentioned veg nutes I'm assuming you are not flowering them yet. If they aren't towards the end of blooming (about week 4) the ph should not be rising like that. I have a feeling that your ph is too high to start with and causing some burning or something similiar like lockout which is causing your ph too rise too quickly.

Here's a chart that Zandor posted about ph....hope it helps

http://boards.cannabis.com/attachmen...oill-hydro.jpg

Hound - Thanks for the responses.

I'm growing in Coco, which I guess is quasi-hydro. The best info I could find on coco is that 6.5 is the correct pH. If that is not correct, I sure wish someone who grows in Coco would tell me what the correct pH should be.

Below is a photo of one of the girls, you can judge if they look healthy or not.

Anyway, my "reservoire" is 5 gal bucket in an unused shower. I mix the nutes 5 gals at a time. It is in this bucket of water & nutes that I have the problem. The pH just doesn't want to stabilize and I'm trying to figure out why.

**stinkyattic** · #5 (**permalink**) May-17-2007, 16:25

I wish I could give you an answer... this is a great question and I am SO tempted to give my old boss a call... he'll know EXACTLY why I am asking, too, lol... he's a great water chemist...

My hunch is an interaction among the fertilizer components you are using, and even with air equilibration as the solution warms up... the CO2 in the atmosphere will go into solution and can exist in a few different forms, such as carbonic acid, carbonate ion, etc. depending upon the oxygenation of your nutrient solution and what other shit you've got in there. Several factors drive the equilibrium in different directions. Damn I wish I could explain it better.

Mixing nutrients immediately before use is a safer bet. Don't give them a chance to equilibrate and change. If you REALLY want to pre-mix a res full, I'd go poke around in the hydro section to see how people deal with stabilizing pH in their reservoirs. I know that humic acid is a good buffer, but I'm the only one who seems to use it (in the form of Soil Syrup) solely for that purpose, and even then I mix and then use immediately.

Your plants look great! The slight reddening of the petioles could be the first signs of a sulfur deficiency, or just strain related; keep an eye out for changes.

I'm curious as to what strain that is. It looks BURLY like ya read about. What awesome side growth, thick stems, stiff leaves... that's my kind of plant!

Anyway I'm not sure as all that was any help at all but to be honest I just gave up on coco for flowering because it's too twitchy... I still use it in veg, and then transplant into a composted humus mix (there's that WONDERFUL humic acid again, saving my lazy ass froom pH problems!!) for flower.

**stinkyattic** · #6 (**permalink**) May-17-2007, 16:26

I just reread my post and the answer popped out at me... there's SOMETHING in there that is buffering at the wrong pH. Either from the source water, or forming from the interactions among ferts.

Just out of curiosity, do you have ANY idea what the calcium content of your tap water is? Instinctively I want to say CaCO3 is bringing your pH up (Ca+ in solution, and CO2 from the atmosphere...)

lol for someone who runs a chem lab, I'm really rusty on the basics~~hope I'm not talking out of my ass on this one!

No more premixing for you!!!

Weedhound · #7 (**permalink**) May-17-2007, 18:34

If it's a soiless medium I call it hydro. As for coco itself I cannot tell you because I use rocks....have never tried coco itself but I thought I heard Stinky mention the word coco here or there.

I do use RO water since I do have ph issues with my well water so that could certainly be a point as Stinky said. If the ph is going up when not even in contact with your plants the issue must be your water. You might be a good candidate to go with RO.
And they do say not to premix your nutes which doesn't make alot of sense to me.....they sit mixed in the rez for a week anyway and the ph always stays spot on.

PharmaCan · #8 (**permalink**) May-17-2007, 22:04

Quote:

Originally Posted by stinkyattic

I just reread my post and the answer popped out at me... there's SOMETHING in there that is buffering at the wrong pH. Either from the source water, or forming from the interactions among ferts.

Just out of curiosity, do you have ANY idea what the calcium content of your tap water is? Instinctively I want to say CaCO3 is bringing your pH up (Ca+ in solution, and CO2 from the atmosphere...)

lol for someone who runs a chem lab, I'm really rusty on the basics~~hope I'm not talking out of my ass on this one!

No more premixing for you!!!

Stinky, thanks for the reply.

I have no idea what the calcium content is, but I've got some pretty high mineral content here. I darn near have to chisel the hard water stains off the shower glass.

If I installed a water softener, that would remove most minerals from the water. Do you think that would help? Daily mixing is no big deal right now, but I'd ultimately like to automate the watering and daily mixing kinda takes the auto out of automate.

That strain is a Master ~ Bubba cross. I smoked some bud from the same mother and it was killer. The plants were studly right from the start. As soon as the clones started growing they were pushing new nodes and leaves out the stem as fast as out the top. I'm growing these girls for mothers. From them I will take clones, which I will flower, keeping good records, and when all is said and done I will keep the best mother and propogate the hell out of her. Hmmmm - wonder where I learned that?

I'm actually kinda wondering which growing method I should use with these ladies and have a thread going on that subject. The plants look like they really want to grow big and bushy and I'd kinda like to let them.

If the grow/plants/strain turn out really well, I could probably be convinced to send a few cuttings to the East coast, especially if it was to someone that could spread them around so a few more people can enjoy them.

PharmaCan · #9 (**permalink**) May-17-2007, 22:12

Quote:

Originally Posted by Weedhound

If it's a soiless medium I call it hydro. As for coco itself I cannot tell you because I use rocks....have never tried coco itself but I thought I heard Stinky mention the word coco here or there.

I do use RO water since I do have ph issues with my well water so that could certainly be a point as Stinky said. If the ph is going up when not even in contact with your plants the issue must be your water. You might be a good candidate to go with RO.
And they do say not to premix your nutes which doesn't make alot of sense to me.....they sit mixed in the rez for a week anyway and the ph always stays spot on.

Hound - Are you trying to tell me that I might be a hydro and not know it? ...Maybe even - a closet hydro? Oh man, I thought hydro was a preference. I didn't know it was something that just kinda happens.
Oh dear, oh dear - what's next? Going organic?

Weedhound · #10 (**permalink**) May-17-2007, 22:40

Well that's what I always thought hydro was....soilless...I do consider coco soilless as it does not contain any nutrients in it that supports plant life. .....it's simply there to provide root support, provide air space etc (I thought...) btw I've been having some troubles with the medium I am using so am looking into coco myself as a possible replacement. Once I find out more about it (which usually means I just call my hydro guy) I'll let you know what I find out.

PharmaCan · #11 (**permalink**) May-17-2007, 23:52

Quote:

Originally Posted by Weedhound

Well that's what I always thought hydro was....soilless...I do consider coco soilless as it does not contain any nutrients in it that supports plant life. .....it's simply there to provide root support, provide air space etc (I thought...) btw I've been having some troubles with the medium I am using so am looking into coco myself as a possible replacement. Once I find out more about it (which usually means I just call my hydro guy) I'll let you know what I find out.

Hound - All my life I've had terrible luck with indoor plants. I could never get the watering right and the plants would ultimately die. I love the Coco. My plants are thriving.

With the Coco right now, I'm hand watering and using the run-off on my outside plants. I'm not recirculating. With the coco you shoot for 10% - 20% run off and water once a day.

If I understood him right, I think one of the coco growers here said that he is watering four times every day.

I've got a good water softener. I guess I should hook it up. I can buy R/O water for now, but that's not a real good long-term solution.

Well, if I'm hydro, I guess I should shoot for an even lower pH than 6.5. What pH should I be at?

PharmaCan · #12 (**permalink**) May-18-2007, 00:02

Here's one of the girls growing in Coco. She's 3 1/2 weeks vegging from clone. I tucked some of the larger fan leaves so the inner veg would get more light, she looked a lot bushier with her fans leaves out.Tomorrow I'm going to move her into a 3 gallon pot of coco.

Weedhound · #13 (**permalink**) May-18-2007, 00:27

Ok I've been off reading up.....coco itself is a hydroponic medium You can easily mix it with other mediums or add it to your soild to assist with drainage etc et.... General hydroponics makes something called CocoTek....they call this a hydroponic medium.....made from coconut husks.

My thought would be that if you have any soil in with your plants I would consider it something you have added to your soil.....like perlite for instance.
(I also read that perlite can be used as a hydroponic medium as well...)
If you are using it as a stand alone product or with mixed with another soilless medium (perlite, vermeculite, hydroton...) you are a hydroponic grower regardless of how often you water. Keep in mind I'm guessing here but I thought it sounded pretty logical.

if you ARE using some soil in the mix I'd probably stick to the 6.5-7.0 range.
Otherwise I'd aim for 5.6-6.1 for your nute solution.

One last bit on your water. I tried a britta filter before i went to ro water and it did not solve my ph problems at all. My hydro guy told me that he tended not to like those kinds of water softeners as they seem to take out the minerals you want (calcium etc) without having much effect on the acid or alkaline condition you are trying to address. I did find this to be true for me but everyone's water is different.

**stinkyattic** · #14 (**permalink**) May-18-2007, 09:16

Quote:

Originally Posted by PharmaCan

Hound - Are you trying to tell me that I might be a hydro and not know it? ...Maybe even - a closet hydro? Oh man, I thought hydro was a preference. I didn't know it was something that just kinda happens.
Oh dear, oh dear - what's next? Going organic? :

I had the same crisis of self image myself recently. lol.

But then I gave myself electro-shock therapy and started back mixing compost into my coco.

It sounds to me like your source water is a SERIOUS problem. Do you live in an area where there is limestone substrate? If so, I am officially patting myself on the back!!!

Mineralized calcium deposits from ancient seabeds... kinda like along the Missouri river... they can REALLY fuck with your grow.

Since you are a hydro grower (sorry....) you pretty much have to deal with the whole total ppm thing. It almost sounds to me like you have 3 choices:

-Buy a RO setup
-Bottled water + Calmag
-Go back to soil (my preferred solution)... My favorite soil mix ever consists of 50-70% composted cow manure wiht humus- the humus is KEY!!!- then the rest whatever lightener you like, I'm currently using a mixture of perlite and coco.

The chelating properties of the humic acids are really going to help you out. But I can't say if it's going to be enough.

The plant in the pic looks healthy for now actually except the sulfur deficiency. Nip that in the bud, no pun intended. I dealt with mine with a combination of switching back to compost, and a product called Cornucopia Bloom- made in Vermont, super high S levels compared to other products, cheap as all get out, nice stuff.

Weedhound · #15 (**permalink**) May-18-2007, 10:22

WELL IT JUST FIGURES that Stinky would have to put some dirt in there, lol. Stinky does what I said make sense to you about the hydro vs soil? I'm
trying to study up on these stupid mediums because I've been having some terrible rootbound issues and need to change to something better. And yes, I agree you should pat yourself on the back if your arms are long enough.

One definition I read of hydro is growing in an inert medium and feeding the plants with a nutrient solution that supplies all their growing needs. This is certainly sounds like said situation to me.

4x5 · #16 (**permalink**) May-18-2007, 10:47

Why not add a second reservoir, (a third with just water and set up a bucket experiment)keep the molasses, superthrive and sweet in one, the 3-parter and calmag in the other; try it, just set them up sitting overnight; you don't even need to hook them up to the system. Then you should see which bucket is reacting with your water, then eliminate ingredients until you've figured which fert or additive is causing the trouble. Cheaper than buying an RO unit.