pH

[SelectOrchids]

I mean, it is really 2000 microsiemens for the feed, and it is not really very high actually, if you know what you are doing ( residual pH equilibrated once the roots take up the fertilizer, micronutrients at a proper level, etc...)

The higher the fertilization used, the more important the pH and residual pH are in fact. When there are more dissolved salts, the plant roots have more trouble to try to correct/balance it. That's why it is complicated too using very high values.

Usually when the plants become chlorotic due to deficiencies ( low feed or individual deficiencies in a specific ion), people recommend to give ' less light' so they green up again. It slows down the metabolism, which makes the leaves greener, but it is not healthy for the plants at all...

 

[terryros]

Thanks, I had it backwards. Those of us using lower fertilizer concentrations (lower EC) don’t have to over worry about pH but need to make sure that we aren’t too low.

 

[dodidoki]

Thanks, I had it backwards. Those of us using lower fertilizer concentrations (lower EC) don’t have to over worry about pH but need to make sure that we aren’t too low.

That is ok, but eg. peters excel growing fertilizer is extremely acidic, its ph et 400 uS 3,6 . Another fertilizer from peters, finisher ph is 6,2 at the same cc. I d like to suggest with that topic , worth to check pH before we use any fertilizer.If i mean well, optimal is pH 5,8 .

 

[terryros]

That is ok, but eg. peters excel growing fertilizer is extremely acidic, its ph et 400 uS 3,6 . Another fertilizer from peters, finisher ph is 6,2 at the same cc. I d like to suggest with that topic , worth to check pH before we use any fertilizer.If i mean well, optimal is pH 5,8 .

Since they exist, I will use a fertilizer that lets me have an EC under 1000 in RO with a pH around 6.0. MSU and K-Lite do that for me.

 

[dodidoki]

Lucky you to have these formulas. Another conclusion for me that as Xavier mentioned, we had a wrong idea about dangerous cc of fertilizers. If i mean well, Xavier has very good results, because he gives his plants higher cc. fertilizer but set the pH correctly around 5,8 pH. Someone noted that if anyone wants to grow a roth from seedling size to bloom it takes at least 5 years....except Xavier, it takes 6 months for him.

 

[terryros]

Lucky you to have these formulas. Another conclusion for me that as Xavier mentioned, we had a wrong idea about dangerous cc of fertilizers. If i mean well, Xavier has very good results, because he gives his plants higher cc. fertilizer but set the pH correctly around 5,8 pH. Someone noted that if anyone wants to grow a roth from seedling size to bloom it takes at least 5 years....except Xavier, it takes 6 months for him.

Istvan, I am most grateful that you started this chain. It caused me to recalibrate my EC and pH meters and test my current solution. I have not done this in years. Surprise! Using an MSU fertilizer in RO, at either 380 EC or 760 (corresponding to about 50 and 100 ppm N) the pH is 3.6. My tap water has an EC of 135 (our water is softened by the city) and a pH of 8.0. I think I am going to use a combination of RO and tap water to make my solution and get a better pH. Maybe 3.6 isn't much of an issue with these lower EC values, but it is easy to make my solution with a combination of RO and tap water AND it will save on RO water! Again, without you I would not have discovered this. Another example of the fun and helpfulness of this international forum.

 

[dodidoki]

You welcome , i learnt many from this forum, too, and have been learning again and again, for many years....this idea with ph can be very useful, if you think about the next situation. You give your plants an optimal fertilizer formula at optimal concentration ( you think, at least...).But plants start to show the symptoms of nutritial deficiency. What a man can do this situation? Increase the cc. And with that he kills his plants....it is a vicious circle, and the problem is the pH. If pH is wrong, plants can t take up nutritients, if you raise cc, pH can get even worse etc. Xavier , as he wrote, gives his fertilizer at 1000 uS, his plants are fabulous. But he always takes care about pH.
Another experiene if you have a suffering plant and repot it into a fresh mix, plant can grow well for a while . It could be because of buffer capacity of the mix.
There are so called ca-lover slippers, they need lime, crushed shell, dolomite etc. in their mix. But!!! However if you make an analysis from ashes of different plants, you can see tha ca content is the same in every case. How could it be? I have a theory. These paphs are not ca lovers really. They tolenance against acidic envirionment is low. They need lime( caco3 or mgco3) as a natural buffer, it protects them against acids. If you give them the same fertilizer with high content of solubile Ca and adjusted pH properly, they don t need lime in the potting mix.
So i think proper name is acid- tolerant slippers and non-acid-tolerant slippers. It does not mean that acid tolerant slippers love the acidic pH. I think after this thread and after reading many articles, optimal pH for all is 5.8.

 

[terryros]

You welcome , i learnt many from this forum, too, and have been learning again and again, for many years....this idea with ph can be very useful, if you think about the next situation. You give your plants an optimal fertilizer formula at optimal concentration ( you think, at least...).But plants start to show the symptoms of nutritial deficiency. What a man can do this situation? Increase the cc. And with that he kills his plants....it is a vicious circle, and the problem is the pH. If pH is wrong, plants can t take up nutritients, if you raise cc, pH can get even worse etc. Xavier , as he wrote, gives his fertilizer at 1000 uS, his plants are fabulous. But he always takes care about pH.
Another experiene if you have a suffering plant and repot it into a fresh mix, plant can grow well for a while . It could be because of buffer capacity of the mix.
There are so called ca-lover slippers, they need lime, crushed shell, dolomite etc. in their mix. But!!! However if you make an analysis from ashes of different plants, you can see tha ca content is the same in every case. How could it be? I have a theory. These paphs are not ca lovers really. They tolenance against acidic envirionment is low. They need lime( caco3 or mgco3) as a natural buffer, it protects them against acids. If you give them the same fertilizer with high content of solubile Ca and adjusted pH properly, they don t need lime in the potting mix.
So i think proper name is acid- tolerant slippers and non-acid-tolerant slippers. It does not mean that acid tolerant slippers love the acidic pH. I think after this thread and after reading many articles, optimal pH for all is 5.8.

Tap water is a source of alkalinity to balance the acidic properties of the fertilizer. Changing fertilizer concentration changes the pH. My city’s tap water is very good with a low EC, but this varies somewhat during the year and this affects pH. Today, I needed about 20% tap water in a 103 ppm N MSU solution with an EC of about 800. In a previous chain Leslie said that he checks pH frequently and uses pH up/down solutions to adjust. I am OK using tap water because it at least saves some RO.

I think I need to be careful because I am growing in 100% LECA (Hydroton), an inorganic material that is supposed to be neutral in terms of pH effects. This is getting close to a hydroponic situation because I water lightly from above almost every day with intermittent feeding.

 

[wongwong]

But one is hard to maintain the pH @5.8 by fertilizer itself, dissolved HCO3- buffer the system ~6.3, once it's mostly gone as CO2, extra acidity drift pH straight below 5.
Ca(NO3)2 unlikely to drift pH down to 3~4,it's quite mild acidic species; pH>6 if you measure conc.CaN stock . Ammonium nitrification provide acidity, or so do maybe co-precipitation of calcium & phosphate di/tribasic species

pH downs from organic acids (as common metabolite/TCA int.) unlikely to last for a few days because of microbes action , so as urea/ amino acid / organic acid anion (as sole organic carbon source)raise pH at least for the first few days

pH5.8; it sounds need to be buffered by acid-soluble carbonate or protonated group in medium/organics under acidifying system
I still concern why paph.s root is more sensitive/ ease of browning /alter in root shoot partition compare with phal.

I don't believe the unsupportiveness of old bark to paph root , is from salt accumulation/acidification/physical breakdown. I still suspect there are some kinds of supportive organics in fresh bark and get exhausted after a few months/yr

===
I recently get a reading on "Nutritional Conditions Required for the Non-Symbiotic Culture of an Achlorophyllous Orchid Galeola septentrionalis"
Urea is supportive together with a.a. mix & casein hydrolysate, but not satisfatory with NO3-or even NH4+; it seems there can be specific N-incorporating pathway for urea that differentiate from NH4+

 

[terryros]

But one is hard to maintain the pH @5.8 by fertilizer itself, dissolved HCO3- buffer the system ~6.3, once it's mostly gone as CO2, extra acidity drift pH straight below 5.
Ca(NO3)2 unlikely to drift pH down to 3~4,it's quite mild acidic species; pH>6 if you measure conc.CaN stock . Ammonium nitrification provide acidity, or so do maybe co-precipitation of calcium & phosphate di/tribasic species

pH downs from organic acids unlikely to last for a few days because of microbes action , so as urea/ amino acid / organic acid anion raise pH at least for the first few days

pH5.8; it sounds need to be buffered by acid-soluble carbonate or protonated group in medium/organics under acidifying system
I still concern why paph.s root is more sensitive/ ease of browning /alter in root shoot partition compare with phal.

I don't believe the unsupportiveness of old bark to paph root , is from salt accumulation/acidification/physical breakdown. I still suspect there are some kinds of supportive organics in fresh bark and get exhausted after a few months/yr

===
I recently get a reading on "Nutritional Conditions Required for the Non-Symbiotic Culture of an Achlorophyllous Orchid Galeola septentrionalis"
Urea is supportive together with a.a. mix & casein hydrolysate, but not satisfatory with NO3-or even NH4+; it seems there can be specific N-incorporating pathway for urea that differentiate from NH4+

It is a complicated system, particularly when you bring organic potting media into the equation.