NYEric
Well-Known Member
Repot!? Does that have something to do with marijuana!? 
Potting practises, frequency of repotting
- Thread starter Bjorn
- Start date
Help Support Slippertalk Orchid Forum:
You know probably rePotme.com?Repot!? Does that have something to do with marijuana!?
troy
Well-Known Member
Wonder what would be a hrsher crime having a joint in colorado or a 2 liter bottle of soda in new york?
That's an absolute fact. Nitrogen plus a carbon source causes the colony to explode.
The petrochem company I work for used a high-N / olive oil emulsion to remediate some of the Exxon Vadez spill. The spray accelerated the native bacterial growth, and when the olive oil was gone, they went to work on the spill. All traces were gone within 6 weeks.
Ray Barkalow
firstrays.com
troy
Well-Known Member
Add a little olive oil to watering? Lol..
I would be pleased to know the pH of RO or rain water in contact with a decomposed bark.
naoki
Well-Known Member
Oh, I see what you are getting. But the initial low pH with fertilization is due to the release of H+ (replaced by cations) which Bjorn explained in the first post. That's why pour-through measured after fertilization show much lower pH (pH 3.8 while fertilizer had pH 6) than the case where water was applied before pour-through. Pour-through was measured 30min after irrigation/fertigation. This initial drop in pH is indicative of high CEC. This is in the first paragraph of Discussion section.
Since we were talking about decay of media, I guess what the author (and I) tried to say is that decrease in pH over time is mainly due to roots (than accelerated decay of moss due to fertilization). In other words, I was talking about the change in pH over time. As you noticed, the change in pH over 30 weeks is small with only fertilization.
I do have the same question as Bjorn, why decayed media is bad (and Bjorn's idea is a possibility which I didn't think). Lance said lack of air. But is it really a issue if we reduce the watering frequency? Well if it is broken down to small size like Clay, then I can see that lack of air could be a problem. But maybe somewhat decayed media provide more stable environment (with regard to soil water potential/osmotic pressure).
Last edited:
troy
Well-Known Member
Thank you brabantia
troy
Well-Known Member
Can you get an acurate measure of media ph by collecting the ran through water or fertilizer mix from the bottom of the pot?
It would be an issue if we reduce the watering frequency. When you have to reduce the watering frequency you are reducing what the plant needs to have to grow...water. In dead media that has no balance of living organisms to provide nutrients the plant relies on water to carry nutrient salts to its roots. If you have to reduce the frequency of watering because of the media condition then that condition is responsible for slower plant growth.
Somewhat decayed media would be a more stable environment. So the issue and challenge for a grower is to alter their watering and fertilizing based of the rate of decay of the media. Trying to do that sets up a route that can easily lead to disaster. That is why decaying media is bad, aside from the lack of air.
You can get an accurate "idea" what the pH is. But not as accurate as a lab result. The pour through method will give a very good idea about the pH the plant roots are subjected to.
What testing with the pour through method actually does is allow you to monitor changes in your media. Once you have a reading and then measure again at a future date you will see if the pH is remaining stable or changing. If it is changing a lot in a bad direction you can make cultural changes to correct the pH. This can help prevent bad problems. The same is true measuring the ppm or ec of the pour through water. You may not be getting the exact accurate measurement but using the same instrument and methods each time does show you what is changing.
Naoki, I see that you understand what I am after. When it comes to moisture etc. we all know that many plants, typically phrags but also some paphs are standing with their roots more or less into flowing water or more common, water seepage. So moisture/wetness is not the problem. Most likely the main problem is the availability of oxygen dissolved in the water, and of course if the "mud" is caused by bacteria consuming available oxygen, then your roots will suffer. Of course, such an environment may be typical for most broken down mixes and if oxygen is not alloewd in the pot, well, then the roots perish. In such a case it might perhaps be a better option to increaser watering frequency in order to refill with fresh, oxygenated water.
Bjorn, you cannot increase your watering frequency because a decaying substrate take a longer time to becomes dry. If you increase the frequency the substrate becomes soggy and the air circulation chances in the substrate becomes null.
I know, and that is why eg baskets work. I water a lot and the compost is soaking wet for many species. No problem with decaying roots so far. But then, I normally use a lot of inorganic pebbles, sand, and other stone-based aggregates in the mix.
Xavier has written about dissolved gases and watering somewhere and he advised to aerate during hot summer particularly by spraying from above.
I have my water in a big tank and heat to perhaps 22degrees. But additional to that I aerate with an aquarium type aereater (stone) from an ozone generator. But I do not think that the ozonegenerator works so its a simple pump probably.
A common problem is of course that people believe that paph roots must dry up. That is not generally true, look at the precipitation data from some of the places e.g. the polyanthas come from, its soaking wet all year.
Others, like many parvis have some drought during winter, but the region has lots of dew during night so perhaps its not that bone dry after all.
Back to start, my point was originally that by adding low amounts of fertiliser and relatively high amounts of calcium, the longevity of the substrate could be increased. All the rest is just to explain why this could be so.
Xavier has written about dissolved gases and watering somewhere and he advised to aerate during hot summer particularly by spraying from above.
I have my water in a big tank and heat to perhaps 22degrees. But additional to that I aerate with an aquarium type aereater (stone) from an ozone generator. But I do not think that the ozonegenerator works so its a simple pump probably.
A common problem is of course that people believe that paph roots must dry up. That is not generally true, look at the precipitation data from some of the places e.g. the polyanthas come from, its soaking wet all year.
Others, like many parvis have some drought during winter, but the region has lots of dew during night so perhaps its not that bone dry after all.
Back to start, my point was originally that by adding low amounts of fertiliser and relatively high amounts of calcium, the longevity of the substrate could be increased. All the rest is just to explain why this could be so.
This is not the first time that I have the feeling that a substrate with a high content in mineral material is a good solution to solve problems linked with the decaying of the substrate and your mode of culture confirms this. Problems for me to test this solution is availability of a good inert material.
This what I use and see my table #23 this thread.
troy
Well-Known Member
Thank you guys for the helpfull info!!!
