PH. Crashing and can't stop it..

[Aqua Man]

Looked up a little more after my last post. I was bang on, so will offer a little more 'possibly wrong' info

You will find P acid more stable than N if your hardness is carbonates. This is because only half of the P acid is available for smoking off carbon. The other half will live in an equilibrium with an equivalent amount of carbonates. It's this balance of having both there, that means a bit more of either, won't make all the difference.

Using N-acid just smokes off the carbon. Gone. Until the acid or carbonates are exhausted. They can't set up any equilibrium.


It's really not something expected to know about when I was at school. I have huge gaps in my understanding.

Yup always phosphoric or sulfuric acid. N as you say decomposed quickly in comparison to P or S acid in our conditions. Prob the worst to use in hydro is citric as it reacts with bicarbonate and is released as co2.

But I disagree here because his problem is PH crashing not raising... so it can't be an issue of the acid breaking down as that would cause PH to crash.


Imo it must be an alkalinity, buffering, stability issue caused from lack of carbonate, bicarbonate, hydroxide or silicate as seen by the rapid drop in PH. If it was an issue of PH rising to fast then I would agree look to the source of acid used.

My guess is there is some ammonium in his nutes and as the plants uptake it the ion exchange is dropping the PH drastically due to an extremely low alkalinity.

 

[Buddernugz]

PH that low is a strong indication of a microbial bloom in your reservoir check your pump make sure it doesn’t have any slime in it…. I have a 50 gallon reservoir every day I have to add 2 mL 55% PH down…depending on the newts you might have to use pH up…. 3.8 is a huge red flag to me….4.0 will burn your roots and contact….. I used to use ro water, now I just use Flora nova…..no more calmag needed

 

[Buddernugz]

Yup always phosphoric or sulfuric acid. N as you say decomposed quickly in comparison to P or S acid in our conditions. Prob the worst to use in hydro is citric as it reacts with bicarbonate and is released as co2.

But I disagree here because his problem is PH crashing not raising... so it can't be an issue of the acid breaking down as that would cause PH to crash.


Imo it must be an alkalinity, buffering, stability issue caused from lack of carbonate, bicarbonate, hydroxide or silicate as seen by the rapid drop in PH. If it was an issue of PH rising to fast then I would agree look to the source of acid used.

My guess is there is some ammonium in his nutes and as the plants uptake it the ion exchange is dropping the PH drastically due to an extremely low alkalinity.

He’s dtw

 

[Aqua Man]

He’s dtw

Can you elaborate on that? I don't understand what the reference is in regards to

My response is addressing DTW and it almost exclusively uses inert or almost inert media that do NOT buffer ph like amended peat or soil would. So you absolutely need to control the PH and the alkalinity/stability is how you do that.

 

[Buddernugz]

Can you elaborate on that? I don't understand what the reference is in regards to

My response is addressing DTW and it almost exclusively uses inert or almost inert media that do NOT buffer ph like amended peat or soil would. So you absolutely need to control the PH and the alkalinity/stability is how you do that.

The end of your post was suggesting the crashing rez ph was due to “My guess is there is some ammonium in his nutes and as the plants uptake it the ion exchange is dropping the PH drastically due to an extremely low alkalinity” which is mute here because he’s drain to waste…it never goes back to the rez.

 

[Buddernugz]

Can you elaborate on that? I don't understand what the reference is in regards to

My response is addressing DTW and it almost exclusively uses inert or almost inert media that do NOT buffer ph like amended peat or soil would. So you absolutely need to control the PH and the alkalinity/stability is how you do that.

if you were referring to another grower hear I apologiz.