• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

How should ppm/ph levels behave in hydroponics?

B

bobbyricky

New Member
Is it normal for both to fluctuate? If so, why? If not, why not?

PPM is fluctuating between 700 - 900 (checked daily) and ph seems to climb daily (requiring ph down every single day).
 
SableZen

SableZen

Well-Known Member
Your ppm will generally fluctuate in a downwards trend as the plant(s) uptake elements (the water become less concentrated with ions). But it can also rise if the plant is drinking more water than it is uptaking (the water becomes more concentrated with ions).

pH tends to rise as the elements in the nutrient solution are taken up by the plant - since cannabis grows in acidic conditions, and hydroponic nutrients are buffered to be acidic, the nutrient solution swings upwards towards neutral (7.0) as the water becomes less concentrated with ions.

Other factors can play a role of course - but those are the general trends you'll see if everything is decent/normal.
 
SnapsProvolone

SnapsProvolone

Well-Known Member
PPM should work it's way down as plants feed. pH tends to rise as plants feed. I like to set at 5.6 & let it rise to 6.0 before bumping back down. 5.8 is the sweet spot but some nutrients are easier to uptake slightly above or below 5.8, so allowing the fluxuation gives best uptake of all nutrients.

If your swings are drastic and rapid then you may need a larger reservoir.
 
B

bobbyricky

New Member
5.5 - 5.7 has been the goal but I've since read that RO water often needs higher ph (5.8 - 6.2) to uptake necessary nutes. Do you agree?
 
SableZen

SableZen

Well-Known Member
bobbyricky said:
What would the numbers look like in situations of minor evaporation? They would rise, right?
Click to expand...
Yeah sure, evaporation would increase concentration of the nutrient solution as well.


bobbyricky said:
5.5 - 5.7 has been the goal but I've since read that RO water often needs higher ph (5.8 - 6.2) to uptake necessary nutes. Do you agree?
Click to expand...
Like SnapsProvolone said, 5.8 is what most people shoot for in hydroponics (regardless of if the water is RO/distilled/tap/etc). But since different elements are more available at different pH readings, and since most growers experience a rising pH in their reservoirs - most will start their pH around 5.6 and let it drift up to 6'ish before correcting it back down again... so a range between 5.6 - 6 is what most people use in practice.
 
B

bobbyricky

New Member
Thank you Snaps and Sable for your input. I'm getting ready to supplement with Cal-Mag due to several yellow clones and it is calling for a ph of 6.2 - 7. I'd post a picture but haven't figured out how to do that without a card reader. I've read that RO water tends to require supplement and I'm assuming if ppm and ph are in range this deficiency is likely the problem. LED lights so I don't think they are burning. The tips first appear burnt then the whole plant turns yellow. Prior to turning yellow they are a rich green (almost purple) color and those leaves are twisting 360 degrees.

So 6.2 - 7 is okay with cal-mag?
 
SableZen

SableZen

Well-Known Member
It sounds like you are reading directions for soil use maybe - even 6.2 is getting too high for hydroponics. 5.8'ish is always where you'll want your reservior pH at.

It also sounds like there's a different major issue going on. Just from what you said about the leaves getting dark and curling first, I would guess you may have burned them with too much nutrients too soon. But you should post some pics in the plant problems section and detail what you have been doing so far.
 
GrowerGoneWild

GrowerGoneWild

Well-Known Member
DarthBlazeAnthony said:
any tips on what the parts per million [ppm] ranges should be during veg or flower stages?
Click to expand...
Varies on strain. Ammount of light, co2 etc... Even style of hydroponics, like DWC.. I use less in that one.

Even manufactures of nutrients feed schedules are kinda heavy.. like heavy 16.. That stuff is HOT.. go with the light schedule, things like General Hydroponics they seem to be better. YMMV.
 
D

DarthBlazeAnthony

Well-Known Member
GrowerGoneWild said:
Varies on strain. Ammount of light, co2 etc... Even style of hydroponics, like DWC.. I use less in that one.

Even manufactures of nutrients feed schedules are kinda heavy.. like heavy 16.. That stuff is HOT.. go with the light schedule, things like General Hydroponics they seem to be better. YMMV.
Click to expand...
heavy 16? like 16x too much? How often would you replace a 5 gallon hydro bucket with fresh water/nutes?
 
SnapsProvolone

SnapsProvolone

Well-Known Member
Strength depends on system type, medium used, plant age and strain, not to mention overall health and environmental factors.

I've had the same strain peak at 1500ppm @ 0.5 in a dwc but only tolerate 1000ppm @ 0.5 in a flood & drain table with hydroton medium.
 
D

DarthBlazeAnthony

Well-Known Member
Waterchange the bucket every 2 weeks...thanks for the tips. I welcome any additional adivce...I just got a ph meter today and ithe reading was high...Knocking the PH down to 5.5-5.9. P1010509.JPG P1010513.JPG P1010517.JPG
 
You must log in or register to reply here.
Top