Growing cattleyas at me

[DrLeslieEe]

I check my pH everytime (also TDS/EC) because I use RO water.

Every fertilizer I have on rotation will vary their pH from 4.4 to 8 after mixing. So I need to adjust it to 5.8-6.2 with pH up/down solutions.

Before I started doing those pH checks, I was salting my roots to death.

 

[dodidoki]

I check my pH everytime (also TDS/EC) because I use RO water.

Every fertilizer I have on rotation will vary their pH from 4.4 to 8 after mixing. So I need to adjust it to 5.8-6.2 with pH up/down solutions.

Before I started doing those pH checks, I was salting my roots to death.

Lower cc. leads to lower change in pH. Maybe

I check my pH everytime (also TDS/EC) because I use RO water.

Every fertilizer I have on rotation will vary their pH from 4.4 to 8 after mixing. So I need to adjust it to 5.8-6.2 with pH up/down solutions.

Before I started doing those pH checks, I was salting my roots to death.

How about was EC then???

 

[dodidoki]

In the form of calcium ca pectinate, it is a key element that ensures the integrity of the cell wall, which is absorbed exclusively through the root system. Because of this, forced shoots without roots are prone to rotting. The absorption of Ca in nature is made possible by the presence of humic acids produced by the roots. The essence of the method I use is that little fertilizer reaches the root level. Perhaps this is precisely why the manufacturer wanted the feed to be slightly acidic. If we neutralize the solution, we make the absorption of Ca impossible, and this can lead to rotting due to the weak cell wall that forms.

 

[terryros]

Istvan, I think you were still probably giving about 100 ppm N per week to your plants during active growth periods?

 

[DrLeslieEe]

In the form of calcium ca pectinate, it is a key element that ensures the integrity of the cell wall, which is absorbed exclusively through the root system. Because of this, forced shoots without roots are prone to rotting. The absorption of Ca in nature is made possible by the presence of humic acids produced by the roots. The essence of the method I use is that little fertilizer reaches the root level. Perhaps this is precisely why the manufacturer wanted the feed to be slightly acidic. If we neutralize the solution, we make the absorption of Ca impossible, and this can lead to rotting due to the weak cell wall that forms.

EC 0.5 to 1.0.

 

[Brabantia]

All forms of calcium are absorbed by the roots. If you fertilize with MSU fertilizer at 50 to 65 ppm nitrogen, you'll see Cattleya leaves become hard. Calcium is in the form of nitrate in this fertilizer. As long as the Ca is in solution, it is absorbed by the roots. Calcium in tap water is in the form of calcium carbonate, and as long as the pH is below 7.5, it too can be absorbed. It also seems to me that Peters 15-5-15 CalMag fertilizer doesn't contain enough Ca and Mg, as it wasn't designed to be used on substrates used for growing orchids, but for soil or potting compost that already contain Ca. Compare the Ca and Mg contents in Peters fertilizer with the contents of MSU or Akerne RainMix at equal nitrogen contents you'll understand what I mean.

 

[dodidoki]

All forms of calcium are absorbed by the roots. If you fertilize with MSU fertilizer at 50 to 65 ppm nitrogen, you'll see Cattleya leaves become hard. Calcium is in the form of nitrate in this fertilizer. As long as the Ca is in solution, it is absorbed by the roots. Calcium in tap water is in the form of calcium carbonate, and as long as the pH is below 7.5, it too can be absorbed. It also seems to me that Peters 15-5-15 CalMag fertilizer doesn't contain enough Ca and Mg, as it wasn't designed to be used on substrates used for growing orchids, but for soil or potting compost that already contain Ca. Compare the Ca and Mg contents in Peters fertilizer with the contents of MSU or Akerne RainMix at equal nitrogen contents you'll understand what I mean.

Yes, maybe right, I don know. Maybe this fact you mentioned( relatively less ca ang mg content of peters) can explain the appearence of black rot on new shoots in late fall/winter at me. Have you ever measured the pH of Peters Excel calmag solution? Eg pH change / 100 uS/cm? If it drops it can be corrected tap water increasing the ca/mg content of solution, too.

 

[Brabantia]

@dodidoki
As for exemple for Masdevallia, I prepare a solution at 40 ppm nitrogen (from 15-5-15). This solution is prepared in a mixture of rainwater and tap water: 40 ml of tap water per liter. I need to add one or two drops of 1molar KOH to achieve a pH of 6.1-6.2. The EC of this solution is 365 µS/cm.

 

[southernbelle]

I check my pH everytime (also TDS/EC) because I use RO water.

Every fertilizer I have on rotation will vary their pH from 4.4 to 8 after mixing. So I need to adjust it to 5.8-6.2 with pH up/down solutions.

Before I started doing those pH checks, I was salting my roots to death.

Which TDS/EC meter do you use. Someone said once that most are not very reliable.

 

[terryros]

Deb, I think the APERA EC20 conductivity meter is pretty reliable and is currently about $50 several places. You can calibrate it with a single calibrator solution when interested in solutions that are less than about 1500. My tap water this morning was 215, my RO water was 15, and the fertigation solution for this month (about 60-70 ppm N of K-Lite) was about 590. The pH (also an Apera meter) was 6.1. I think your MSU at the same strength wouldn’t be much different.

 

[Brabantia]

Which TDS/EC meter do you use. Someone said once that most are not very reliable.

I use a conductivity meter purchased from Ali.....ss. Its accuracy is quite sufficient for our orchids. If you calibrate the conductivity meter with a solution of known conductivity, your reading can't be wrong. You can buy a 0.005M KCL solution with a conductivity of 718 µS/cm at 25°C.

 

[southernbelle]

Deb, I think the APERA EC20 conductivity meter is pretty reliable and is currently about $50 several places. You can calibrate it with a single calibrator solution when interested in solutions that are less than about 1500. My tap water this morning was 215, my RO water was 15, and the fertigation solution for this month (about 60-70 ppm N of K-Lite) was about 590. The pH (also an Apera meter) was 6.1. I think your MSU at the same strength wouldn’t be much different.

Thanks

 

[Brabantia]

A brief comment about adding tap water. This not only raises the pH of the fertilizer solution, but also counteracts the pH decrease of the substrate, as would the addition of dolomite or oyster shells. When watering with rainwater, you can also add a little tap water for the same reason. This provides a little Calcium and Magnesium, and perhaps other trace elements not present in chemical fertilizers.