Constant PH issue in RDWC UC after switch to calcinit/kristalon

[LK1]

I took the jump to powdered nutes I have been using Yara Kristalon Brown and Yara Calcinit

Since switching from bottled nutes i've had the whole system PH dropping from 6.5 > 4.5 in 2 days this has been ongoing throughout flower and I've tried everything (it was fine in veg until about week 2 floweer)

- Adding more P and K with MKP and pottasium sulfate
- Switching to nitric acid for PH down
-Running much less calcinit in comparison to kristalon

So far nothing has worked and it's a real headache, before with the top off resevoir I was able to keep a nice steady PH, but now even with a top of res of 6.9 PH and plants drinking large amounts the system ph will still drop super quick. The PPM stays pretty stable and doesn't rise or lower much at all. My tap water has a hardness of 275ppm it worked well with hard water nutrients from the bottle but always felt there was room for improvement, but these PH issues are driving me crazy


Any idea where I could be going wrong here?

 

[Zill]

LK,

Not familiar with that fertilizer brand. Kiristalon Brown is formulated with 27% SO3. In water SO3 can ionize to H2SO4, sulphide acid.

Zill.

 

[Zill]

Sulphuric acid.

 

[LK1]

What can be done to avoid this? I've not heard of that issue before

 

[Zill]

I was surprised to see 27% NO3. Stop using it or buy a dry fertilizer formulated without NO3.

Before we go nuts try this….take some of that Brown stuff and mix with water at the recommended rate. Measure the pH of the water before you add the Brown. Did the Brown drop the pH?

 

[CowDog]

What can be done to avoid this? I've not heard of that issue before

Complete res flush and switch back to your liquid nutrients immediately.
No need to perform a science experiment here at the potential expense of yield.

 

[monkey47]

Powdered nutes in a dwc or rdwc set up ? I would heavily advise to use a chelated nutrient solution so you ll probably be stuck with liquids. Are powders cheaper ? I can imagine they won't mix that perfectly messing up your ph constantly.

 

[Zill]

Salts are infinitely soluble in water. Why pay for someone else’s water?

 

[LK1]

I was surprised to see 27% NO3. Stop using it or buy a dry fertilizer formulated without NO3.

Before we go nuts try this….take some of that Brown stuff and mix with water at the recommended rate. Measure the pH of the water before you add the Brown. Did the Brown drop the pH?

• N15.5%
  • Nitrate - N14.4%
  • Ammoniacal - N1.1%

Where did you get 27% NO3?

The issue is not solubility there just seems to be some reaction driving the PH down constantly. I'm thinking it could be overfeeding but I'm only at 1.1 EC or 550ppm which is normal when using bottles. The kristalon brown does not drop the pH by much, there is no drops when mixing it just happens when the plants feed and its very agressively dropping constantly but the PPM is staying static.

 

[Zill]

Look at the listed components. Way off to the right is NO3, 27%.

 

[Zill]

LK,

I looked again. Different screen shows SO3 at 27%. I wonder if the other is a typo?

 

[Zill]

My mistake. 27% is SO3

 

[Zill]

LK,
27% SO3 will lower the pH.

 

[LK1]

Do you know what nutrients companies do differently in a hard water formula? I've always had my PH rise steadily after a new res change then back down when the plants alter the composition of the mix and I know when it's time for a res change, but here the PH is driven down constantly after a change of res

 

[Zill]

LK,
I doubt they formulate fertilizers based on water hardness. Switch fertilizer suppliers. These Yara brand fertilizers are commercial and sold to folks using it in broad soil applications. Soil itself is somewhat buffered and can resist a push to acid or basic.
Zill.

 

[Choppr]

Im seeing so3 also, but sulphate sulfur is common in a lot Big Ag Nutrients, but 27% of the formula seems high...? Looking at the NPK the epsilon red (12-12-36) not optimal but might've been another choice, Epsilon says they're Soluble for fertigation systems...

Can You get Greenleaf Nutrients? I thought there was another guy on the forum? Aussie maybe? saying He got Greenleaf (MegaCrop)... Ive been in Hydro a long time, settled with MegaCrop, both in Coco/DWC - Ive tested many nutrient lines over the years, for the money MC is a winner!

hope you figure it out!

 

[Zill]

Thank you Chopper!