Ph runoff in biobizz lightmix

[Solrider666]

Ok so here we go.

I am a noob you have been warned.

I am using the following

Biobizz light mix
Filtered water from a britta water filter which brings it from 8.2 out the tap to 6.0, i am using ph up and down (mainly up) with intense dirt bloom. They are meant to be finished in 7-8 weeks and i would say thats about correct. They are 5 weeks and 2 days in.

Watered a few days ago and checked runoff going in was 6.7 coming out was 6.0 and they had a fair amount of nutes and had a bit of burn. So today i used clean ph'd water of 6.7-6.8 and to my amazement the ph dropped to 5.7/5.8 runoff. ive used about 6 litres to flush it through but still the runoff is to low. What is causing this?

The plant is starting to go yellow at the bottom and some upper leaves are turning yellow. This is why i flushed to get the ph of the soil back up a bit to avoid lockout

Am i rightin what im trying to acheive?

Just to clarify its only this 1 i am having an issue with and my ph meter is not a cheap one and calibrated.

Any help would be greatly appreciated

Thankyou

 

[Colossus]

I was under the impression soil contains its own nutrients!

So adding more is somewhat overkill?

 

[TheSappling]

Hello, this is from a while back, but since there is still no reply’s I must say my peace!

I have and have had the same problem, and no one can give me an answer.
Growing 6 auto flowers now.
I’ve grown since 2016 and used a lot of different potting mixes.
Now I use Bio Bizz light mix.

After two-three weeks I started giving only a few drops of the right nutrients also from Bio Bizz, plus microbes.
And I mean 3-4 times less nutrients then recommended.

The water that goes in is always PH’d 6.5
And last feed was 380 PPM
Last run off came out
PH - 6.2
PPM - 1020

Then I watered a week later
PH - 6.7
PPM - 450(just to test)

Runoff
PH - 5.8
PPM - 1370

My opinion is that the peat moss is a poor cannabis medium, and the build up is causing the PH to go down, if you switch to coco it would be way easier to control both PH and PPM.
Either that or you make an organic super soil and just water when dry, you can do that with dry amendments both with non peat based soil and coco coir.

Peat moss can hold good amounts of CO2 in the medium, that’s the only plus.
I’m tired of so called “organic peat based soil mix”
Same nutrient build up and PH problems.
The best you can do with peat is to just add water until your runoff comes out at below 400-500 PPM(or plants showing first signs of deficiency)and that can take a while.

(Remember it can be really good productivity in plants under precision stress, but only a few micro tweaks, never to much.)

They say you can start adding nutrients to light mix after the second week, but you can easily wait to around week 5-6 before adding anything other than microbes and then slowly increase PPM from there.
Try and always add microbes when you water because they help the plant take up nutrients more efficiently with less stress.
It’s just the same with adding nutrients, if the label says 4ml per liter water add only 0.5 - 1ml in the beginning.
If the soil mix says after 2-3 weeks you can prolong that to at least 5 weeks or longer.

I hope this is somewhat helpful, and since it is a good good while ago, maybe you have some insight then back in 2021.

Happy growing !

 

[TheSappling]

I was under the impression soil contains its own nutrients!

So adding more is somewhat overkill?

Well you are right !
But eventually the soil can run out of nutrients especially with peat based soil,
and in this case it’s talk about Light Mix witch contains less nutrients then all mix.
Peat based soil mix is only mimicking organic super soil, so that one time in the future you will have to start adding nutrients to keep it that way.