Some Newbies

[Tony]

I treated my whole growing area with gnatrol a few years ago and it has kept them away really well.

What type of area do you grow in? I have an indoor area with some CFL's for lighting, I use it for my smaller cacti and seedlings. I also try to stay organic if I can, is gnatrol organic?

Yes it is, here is a link that explains what it is.
http://www.valent.com/Data/Labels/2008- ... 0%20R1.pdf
the area I used it on is a small green house with a dirt floor. I have seen only a few since treating the soil inside and out.

[Cacti77]

Great, thanks for the info Tony.

[Cacti77]

Distilled water has an effect on other liquids. Mixing two liquids with different salt concentrations, the low-concentrated (distilled) water "overtakes" the other. Both mix and balance out the concentration. If a semi-permeable layer between them,(here the outer skin of plants) the distilled water migrates to the inside of the plant.
The best choice should be water from a well or rainwater.

This makes no sense. Rainwater is distilled water, just distilled by the sun instead of in a factory. Both contain dissolved solids at the ppm level, which can be contaminants from collection and storage, or may be dusts in rainwater or even salt if you live near the seas. Graded water may contained less than 1ppm dissolved solids, but this is no longer made by distillation and sold Rainwater may contain more dissolved nitrogen and sulphur gases, or may not if you live somewhere without much pollution. You can also create your own distilled water with a solar still or fog catcher, but these tend to have even higher levels of dissolved solids from being collected on solid surfaces.

Well water is by definition groundwater and will contain dissolved solids at high to extremely high levels. It can be far worse than the worst tap water, although occasionally quite pure. It is often heavily loaded with a particular mineral or with nutrients from leaching. Use caution.

Tap water can be soft and largely free of dissolved solids, or can be hard with mostly calcium and magnesium sulphates and carbonates, occasionally other minerals. It will usually have some form of disinfectant in it, and if that is strong enough that you don't want to drink it then you probably shouldn't put it on your plants either. It is probably worth mentioning reverse osmosis water which has nearly all the dissolved solids removed, but may still contain dissolved organics. Softened water from a device using salt is not suitable for plants as it contains too much sodium, or occasionally potassium, which will become toxic over time.

All water, unless boiled or condensed and stored in air-tight conditions, will contain dissolved atmospheric gases. The most important for plants is carbon dioxide which makes pure water quite acidic, although it is not a strong enough acid to counteract hard water unless you're prepared to bubble air though it for a few weeks.

Your description of osmosis in the roots implies that using very pure water encourages the plant to take up the water. This is bad how? There is also the suggestion that somehow the distilled water would go into the plants leaving behind something else. Leaving behind "better" water? Leaving behind nutrients? Doesn't this also mean that water with fertiliser isn't taken up by the plant?

WOW, that was a great read. Thank you for posting.

[Cacti77]

Here is another pic from a different pot, this pot only has 4 seedlings in it.

The picture is not that great, kinda blurry. I like to put a thin layer of sand on top of the substrate to help the seedlings stand up when young, it also helps with gnats by not allowing them access to the soil underneath, their larvae cannot get at the roots.



I still have no idea what genera I am growing, I think some might be Pachycereus pringlei and maybe some Ferocactus.

[DannabisAx]

Your description of osmosis in the roots implies that using very pure water encourages the plant to take up the water. This is bad how? There is also the suggestion that somehow the distilled water would go into the plants leaving behind something else. Leaving behind "better" water? Leaving behind nutrients? Doesn't this also mean that water with fertiliser isn't taken up by the plant

How osmosis works is high concentrations move to low concentrations to equal everything out.

My highschool teacher used the example of farting in a stall, at first the gas is highly concentrated in the stall and there is very little gas in the rest of the bathroom. Then the gas spreads out until equilibrium is achieved.

What this means for roots and plants is that water that is extremely pure has lower concentrations of water soluble nutrients than the plant and its roots.
Through osmosis, the pure water sort of tries to 'suck' nutrients from the plants roots until equilibrium is established.


I don't think it has anything to do with encouraging the plant to take up water.

That sounds more like the capillary action of water to me which is a slightly different idea.


But Iann, your note about water softening via salt is pretty useful to me, since I am probably slowly salting my plants to death since I have a well and use a water softener (Salt). Thanks for the info. This is a very interesting and mildly confusing subject.
Rain water seems to be often recommended and since you pointed out the similarity of distilled water and rain water, I wonder why distilled water is so disreputed..

quite some food for thought.

[Peterthecactusguy]

Your description of osmosis in the roots implies that using very pure water encourages the plant to take up the water. This is bad how? There is also the suggestion that somehow the distilled water would go into the plants leaving behind something else. Leaving behind "better" water? Leaving behind nutrients? Doesn't this also mean that water with fertiliser isn't taken up by the plant

How osmosis works is high concentrations move to low concentrations to equal everything out.

My highschool teacher used the example of farting in a stall, at first the gas is highly concentrated in the stall and there is very little gas in the rest of the bathroom. Then the gas spreads out until equilibrium is achieved.

What this means for roots and plants is that water that is extremely pure has lower concentrations of water soluble nutrients than the plant and its roots.
Through osmosis, the pure water sort of tries to 'suck' nutrients from the plants roots until equilibrium is established.


I don't think it has anything to do with encouraging the plant to take up water.

That sounds more like the capillary action of water to me which is a slightly different idea.


But Iann, your note about water softening via salt is pretty useful to me, since I am probably slowly salting my plants to death since I have a well and use a water softener (Salt). Thanks for the info. This is a very interesting and mildly confusing subject.
Rain water seems to be often recommended and since you pointed out the similarity of distilled water and rain water, I wonder why distilled water is so disreputed..

quite some food for thought.

Don't water your plants with water softened water, it contains lots of salts which are bad for plants. I don't have an explanation for why, I am not a chemist, I used to work at a place that had de-ionized water, which is water that is filtered and run through UV light and probably a lot of crap too. Anyways they watered all the plants with the de-ionized water and not the water that they had softened. We had to clean mirrors for environmental tests and it had to be pure water with no impurities in it.

[DannabisAx]

yeah, I've been thinking and it occurs to me that maybe the water can be pure because the soil should bear the nutrients, right?

If you have to choose between reverse osmosis filtered water and softened well water which would seem more appealing?

[CactusFanDan]

If you have to choose between reverse osmosis filtered water and softened well water which would seem more appealing?

There isn't much I'd personally use reverse osmosis water for, it's essentially just H20, with nothing, initially, dissolved in it. Once it gets exposed to air, though, all variety of gases dissolve in it, oxygen, carbon dioxide, nitrous oxides etc. I'd certainly go with the softened well water.

As for the root osmosis discussion, osmosis is the movement of water molecules across a semi-permeable membrane, moving from the lowest concentration to the highest concentration. This is how plants take in water, but nutrient ions need to be moved across the cell membranes via active transport by special swivelling proteins in the root wall. Bit about root function for you guys there.

[iann]

Oh what fun. Water first, roots later.

I wonder why distilled water is so disreputed

I have no idea. I can only imagine that the current cultural bias for "natural" products causes people to consider distilled water or de-ionised water to be somehow inferior to water that appears out of the ground or falls from the sky. It is worth noting that distilled water is considered almost essential by growers of some types of plants such as carnivorous plants.

Reverse osmosis water is not as pure as distilled water, certainly not H2O with nothing dissolved in it. Reverse osmosis is essentially filtered water and any molecules or ions larger than a certain size are not removed. Typically reverse osmosis allows sufficient bacteria to remain in the water that drinking water would need to be further treated by a process such UV irradiation or chlorination. You can use any of these types of purified water for plants. I have no idea why some people have a problem with this.

If you have well water, you probably have a pretty good idea what is in it or you wouldn't be drinking it. So you should have an idea if it contains anything that would be a problem for your plants. Salt softening any hard water, from a well or from a tap, usually means replacing calcium ions with sodium ions. Most plants will not tolerate the resulting water for long. You can also replace with potassium. Some people use this on their plants, although I wouldn't just to be safe. That would be persistent and fairly heavy fertilising with potassium, which is going to cause trouble sooner or later. A likely symptom would be chlorosis caused by deficiencies induced by the excess potassium.

exposed to air, though, all variety of gases dissolve in it, oxygen, carbon dioxide, nitrous oxides etc. I'd certainly go with the softened well water.

As if the well water doesn't have those gases dissolved in it (unless perhaps it is horribly hard and has neutralised all the carbon dioxide)? Which gases in particular do you have a problem with? Rainwater of course includes the same gases and very few people would argue that rainwater is very good for plants.

[iann]

Root ion transport is complex and not fully understood. It is broadly broken down into two types, active and passive, although there are certainly more than two mechanisms for transporting nutrients ions into the roots.

Active ion transport is a process where proteins physically transfer individual ions from one side of a cell membrane to the other. It requires energy and can transport ions from a less concentrated solution to a more concentrated one. In practice there are several steps involved and there are probably different combinations of steps in different species to cope with particular environments.

Passive transport, also known simply as diffusion, is a non-energetic transfer of ions from a more concentrated solution to a less concentrated one. This could simply be osmosis, but in roots it appears to be a more complex mediated or facilitated transfer where certain ions are excluded or preferred. There are almost certainly multiple physical processes involved.

So plants can take up ions from solutions with a wide range of concentrations, higher or lower than their internal cell concentrations. Different species are likely to be adapted to work most effectively in their own environment, and probably they have a range of adaptation during growth. An obvious example is halophytic plants where mechanisms have been found to exclude or segregate sodium ions and plants have been shown to adapt to changes in the saltiness of their water.

Once taken into the root surface, ions diffuse into the xylem along with water. Xylem is not alive and this is a purely passive process usually driven by suction produced by transpiration, although there are other mechanisms in cacti. Apparently some roots skip some of these complexities and simply have the xylem in contact with the soil and take up water directly along with any ions in it. This may be energetically favourable and efficient in ideal conditions, but perhaps not as adaptable in adverse conditions.

[Cacti77]

iann, I have carnivorous plants so that is one of the reasons I always have distilled water around. I am good at growing them, well at least the couple of genera/species I have (fly traps, sundews)

[Cacti777]

I had changed my password to this site and forgot my email address password as well so I cannot get a new password sent to me so this is my new user name.

Anyways here are some pics, I am wondering if anyone can tell what genera I might have. I think I see a few Pachycereus pringlei, maybe a Ferocactus or two and some that I do not know about. Also my Mammillaria seeds have started to germinate

Pics:

Mamm seedlings




Pachycereus pringlei?



Fero on the left maybe, and something else.



A couple of unidentified seedlings.



Newbies.

[osac]

very nice

how old are those litlle ones? ...last pic

thanks

[Cacti77]

An update on my seedlings>>>







I need to move some to new pots I think, there growth has slowed down a decent amount. I gave them a weak dose of fertilizer and that greened them up but I think they need more root space.

Some are growing fine in close proximity to each other, some are not.

Here are some of my Mamm seeds from this years harvest>>>

[Scottyzx12]

Woww!! Its great to see the seedlings develop!