Nutrient Strength pH Balance Relationship?

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Originally Posted by doco

looks like they went up - 1325 ppm right now. When I started this fresh batch Monday night it was 1250 ppm - Whats that indicate?

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Hey Doco ,
W/H is right - evap. / transp. of water into air or h2o that plants have used faster than nute uptake will increse ppm . numbers . I top off my res . w/ just un p/h'd r/o water when needed and this ups my ph bk. where it belongs w/o so much up / dwn chems and it brings ppm bk down . I still havta p/h the whole res 1 -2 times a day tho because ph is still dropping here ?
I have found the higher the ppm is the more stable my ph is tho. I think it's because theres more buffers in the mix w/ higher nute concentrations .
If ppm has dropped considerably between the 7-10 lapse of res changes I give em some more nutes mixed in w/ r/o when topping off the res.
Peace
Crispi :jointsmile:

I'm a newb still but I definately notice if the ph is higher like closer to 6 the plants can take a higher ppm of food but at around 5.2 I've noticed that the ppm tolerance is much lower although even at a bit lower ppm they seem to grow better

during a res change you have to compare the ppm before you replace with the new water any difference between those will cause a drift depending on how different the ppm

I have topped 1 footers in first day of 12/12 and I started them at just 500ppm maxibloom with ph at 5.2ish and last time I was at 800ppm to make them happy with 5.8ish ph

I just try to pay attention the first day of a res change and after that ya kinda know which direction and rate it's headin...but I do think there is some subtle connection between the life cycle and the excretion of the plant that causes ph to change I'd say if yer havin issues with ph travel put it to 5.5 and you have 1/2 a point to wander before it's any real issue on both sides ;-)

ASD I love you man.....you slay me with the ph talk.....:thumbsup:

Thanks for all the comments boys & girls. It was at 5.4 again tonight and when I left this morning I had it at 5.7 so it is still falling regularly.

I did a websearch and found falling pH associated with root decay so I lifted my buckets and the roots all look healthy as far as I could tell in the yellow HPS light anyway. My res temps are a bit higher than optimal but not by much - 73 at the moment but lights just came on - it'll get to 75 or so. I know that is starting to push the envelope. Does anyone here use a chiller with just a small waterfarm res? I mean its only 12 gallons....sheesh.

I tossed in 30ml more Hydroguard just for good measure and I may look at what dosage levels I should use H202 at, which I have never used before. If anyone uses it, gimme a shout.

Now I know how we scared Stinky off hydro LOL!!!

Hey Doco I use it sometimes....I was using a teaspoon a gallon for algae control and when that didn't work i was told to double it so now I use 20mls for 2/1/2 gallons....we are talking the store bought 3% here....every other day. I've sort of gotten away from it because I was using the cannazym and you can't use both but I've been using it in the veg stage of my grow this round at that dose.

Hi I was reading in the FAQ that wen your ppm is down you use a base npk to top of you water ! there is a math formula at : Text
I was just wondering if you use this formula ?
And how this precise â??nutrients monitoringâ?� will effect our plant`s /yield at final harvest ?
I know it`s important to have a stable ppm but how important is it to have a correct does of N,P OR K ? (example : 1 tbs of N 2 tds of p 5 tbs of k = xxx ppm to top off water )
I have not hade the money to get a tds/ec metter to read my ppm I have just folioing G.H feeding chart and top off whit just water no new food on a daily base

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Originally Posted by doco

I may look at what dosage levels I should use H202 at, which I have never used before. If anyone uses it, gimme a shout.

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I use 50% (horticultural grade) H2O2 at 1ml/litre every 3-4 days as an antimicrobial. Plants will tolerate 10x that concentration with no ill effect.

If you have an acute pathogen problem in a tank, do a one time dose at 5ml/litre then return to 1ml/L per 3-4 days.

Pharmacy grades at 3% & 6% can also be used, but it gets expensive if your tanks are large. Apply 3% @ 17ml/L and 6% at 8ml/L.

H2O2 can't be used with organics; it will break them down on contact.

Wow....impressive to whip those dosages off. I will take issue with your last line though....i use Botanicare and was told to use H202 along with it and have never had a problem and never had any sort of problem using them together. Anything along the line of cannazym or something however....no h202. ;)

Thanks WH, this stuff just accumulates in my brain. ;)

If the maker of something says it's OK with H2O2, coolio. However, you can do your own compatibility test in a teacup. A little water, some of the material you want to test and some H2O2. If the mix foams or bubbles when you add H2O2, chances are there's organic materials in the material you're testing and H2O2 is breaking them down.

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Originally Posted by stoneinks

I know it`s important to have a stable ppm but how important is it to have a correct does of N,P OR K ?

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Unfortunately, it's not possible to tell how much of a given nutrient exists in a solution with the usual nute meters (and yes, a nute meter is a necessary item in a hydro grow).

TDS meters do just that- they display total dissolved solids (salts) concentration information. They cannot tell you how much individual N, P or K is in your nutes.

You're smarter to simply mix whole tanks per the nutrient maker's instruction and dump/clean your tanks every 2 weeks (or whatever interval your nute maker specifies), adding only plain water as needed between dumps. Don't add more nutes between tank dumps.

If a 2-week dump interval is specified, the chemistry has been engineered so there is a sufficient amount of N, P, K and other nutes for that 2-week tank life and they are present in the correct ratios to one another. If you add nutes in the middle of the tank life, you're very likely to alter the N:P:K ratio to something the maker didn't intend- and your ppm meter can't tell you if there's a problem.

Trying to jockey the nute strength to the same ppm on a daily basis invites nute burns. Resist the urge to fiddle.