Question about runoff ph in coco.

[sourpickle]

I'm running coco/perlite (60/40) KISS-maxi bloom.
I trying to keep run off between 5.8-6.1 by adjusting feed water.
Have I got this backwards? Should I just ph in going feed and not check run off? How do y'all handle this. I have noticed when run off ph is low plants are a little yellow, when ph is high leaves twist.

 

[Snype]

I'm running coco/perlite (60/40) KISS-maxi bloom.
I trying to keep run off between 5.8-6.1 by adjusting feed water.
Have I got this backwards? Should I just ph in going feed and not check run off? How do y'all handle this. I have noticed when run off ph is low plants are a little yellow, when ph is high leaves twist.

I would rather be in a range of 6.0 - 6.4 for coco. The run-off will tell you lots of information. You will want to check the pH and EC of your run-off to see what they are coming out at. I would want to see the run-off pH coming out at between these levels and if they weren't then I would adjust accordingly.

If I was in Rockwool or another hydro medium, I would be in a range of 5.8-6.2 but coco is different.

 

[sourpickle]

About 15 days ago I had the idea that I could use run off ec and ph to read what The plant is doing Similar to the way you would in a Hydro system reservoir. So I have been writing down Feed E.C. And PH, then the runoff E.C. And PH, To try to glean some info. And this limited info brought up some questions.

 

[Snype]

About 15 days ago I had the idea that I could use run off ec and ph to read what The plant is doing Similar to the way you would in a Hydro system reservoir. So I have been writing down Feed E.C. And PH, then the runoff E.C. And PH, To try to glean some info. And this limited info brought up some questions.

That's really great that you've been collecting data! You will learn a lot from it. Good luck.

 

[noreason]

At now I have enough knowledge to avoid pH and EC of the run-off but I did it many times in the past.

EC measurement is not accurate in the run-off. To be accurate you should use the same exactly quantity of water at every check, to keep the same solvent/solutes ratio. But this include the water retained from the coco fiber too. So it's kinda difficult to be accurate, but I agree it can be a useful information, even if it's not accurate.

At now I avoid to use acids to lower my tap water pH that range from 7.6 to 8. It is pretty useless as my water is not so alkaline and plants are healthy. However I agree with those who say to keep pH around 6 or above. I noticed plants feel more comfy with that pH, but this in a general view, I grew great plants with 5.5 pH without any trouble.

To be accurate on a pH checking, I can suggest to use deionized water. First because it has no bicarbonates and it can't neutralize H+ ions. Plus it has no other salts that can react with other compounds making the measurement not accurate.

And finally because having no H3O+ or OH- in it (or almost, because the formations of ions is a natural process that can't be stopped in water at ambient temperature), you can use a different quantity of water without caring of it, pH will be not influenced by this and the value will be the same (almost the same because the dilution, but it can be not considered as in the final pH the margin is minimal).

Obviously using deionized water is like flushing the medium. So take it in mind

Hope this can help someone

Coco rocks!

 

[Medicgray]

I have found yellow and twisting leaves when I adjust incoming pH more than 0.2EC; just try to keep it at aroung 5.8 veg and 6.0 flower and water frequently. that will keep the run-off pH and EC stable. If you allow it to dry out too much inbetween waterings the run-off ph and EC will be all over the place. I try to feed at least every 24hrs. w a little run-off.(maybe 10%) plants are better with 12hr feeds, and that's what I shoot for but life gets in the way sometimes. If you let it go more than 24hrs then you'll need the 20-40% runoff, or else salts build up w repeated long periods between waterings.