hempgirl

I know we want the best water for out girls, and I happen to make demin water along with RO water, as well as RO water without Hypochlorite(chlorine) woud demin water be useful or would the lack of minerals be bad for the plant?
then what about RO water? this is just cleaned water, so you can drink it, but is it better?
grow the best as we can
hempgirl

__________________
let's all have a toke
and we'll be alright

organic

The best kind of water to use, I've heard, is mineral water (like Volvic). As you guessed, the minerals are good for the plants. Not having them won't necessarily be *bad* for the plants, but having minerals in there is better.

I think the RO (I assume you mean reverse-osmosis filtered) water is fine, all other things being equal. Having potential nasties filtered out of it can't be anything but good for the plant.

The only thing you really need to watch out for as far as water are chlorine content and salt. But you knew that already

rganic

bgetting

RO water should be relatively free of salts and what not, and should be plenty pure enough to use for plants. The only water that is purer is DI (de-ionized) water, which is sometimes called double distilled (DD) water. This is ultra pure, with no ions in it at all. The pH will be 7 on the dot.

The purer the water, the faster it will go into a plant (in hydro anyway) In soil it will pick up ions on its way through the dirt. In hydro, the water potential difference will make DI water just force into the plant, which can be good. (I use pure DI water, with 1 tsp/gal of pure cane sugar for a week to clear, then just plain DI water for another week).

You shouldn't need water this pure, but you should also get a readout form your local water system about what is in the water. I lived in the midwest for a while where the tap water was horrible! (pregnant women and children weren't wupposed to drink it.) In that case, I would go with RO water that you can get out of a machine at the supermarket.

organic

Hey, B, while you're on the subject could you give us all a short primer on ions and their role in nutrient uptake in plants?

Thanks
- O -

hempgirl

I figured demin water wouldn't be the best, and yes I do mean reverse osmosis water. I happen to make both kinds of water, and I have the control of chlorine content that goes into it. I haven't heard of DI water though, in demin water the water goes through a mixed bed demineralizer, both with IONS so I will let you know what I know of them... humm!!
ok ions are charged particles either positive or negative, hence, cationic for positive, anion for negative,if there isn't any ions then there is nothing for the H2O to grab hold of so then how does it get soaked into the plant? wiater soaks up through the roots but there has to be a negative and positive charge for the roots to take it in. I am not sure if there isn't ions then what keeps the water from not seperating from the other things it contains? like silica, and conductivity? don't know..
anyway that's part of what I know, I can't go into too much detail it takes too long..
hope it helped some??
hempgirl

__________________
let's all have a toke
and we'll be alright

organic

Feel free to go into detail. It might be over some of our heads, but it's of use to the more experienced growers and those who just like to learn. I take it you have a scientific background?
Share it!

-

hempgirl

I get the chance to work with allot of different chemicals,I never thought they might be useful in such a wanderful way!! I make water so I have to know what it's made of. like hydrogen, and oxygen... for chemicals and water... pretty much everything has some sort of ionic charge or they wont stay together. negative attracts positive... if water has H2O meaning 2 hydrogen and one oxygen it is positively charged. so then when it is added to soil, it is looking for another negative charge to become complete and neutral.. so the roots have ionic charge in the for the water to want to soak into the roots.
when soil is mixed with nutrients, the roots will take up what they are missing and generally toss away the rest, leaving the build up. (there isn't any more ionic charge for the roots to grab hold of, hence it is neutral and until it is used up all the charge, it won't take any more and leave the rest sitting there to rot and pile up, making it hard for the plant to breathe...
so I am confused on the DI water, to me DI water is distilled water?? help me understand a bit?
ok that was long, I don't want to bore anyone...
hempgirl

__________________
let's all have a toke
and we'll be alright

organic

Don't worry about boring people, if they aren't interested then they don't have to read it. Generally people put too little information into posts, not too much. Thanks for the info!
(sorry I can't help out with your questions in this thread, bgetting has the science background and can probably help you out more.)

bgetting

Alrighty then, here we go.

First off, DI is deionozed. It is treated to have no ionic components whatsoever. This also means that any stray protons or hydroxide ions are removed, giving it a pH of 7, and minimizing the chances of autoionization, which can interefere with additives that we may add to it. I do water testing, so this is key.

Second, water transport in plants: This one might be a little long, hope nobody gets bored. Water has what is called water potential. With a membrane involved, this water potential can cause the movement of water. This is what drives water's urge to equalize across a membrane. What this means is that if you have two solutions, divided by a semi-permeable membrane (reynold's wrap, plant cell membrane), where one solution has a concentration of 1500 ppm, and the other has a concentration of 10 ppm. The water will flow from the 10 ppm side to the 1500 ppm side in order to dilute it and equalize the concentration across the membrane. Since the cells in the roots of a plant have salts, proteins, and all kinds of other **** in them, water wants to equalize. So if you put the roots in 0 ppm water, the water will push itself into the roots. But if you put them in water that is 5000 ppm (greater than the concentration in the plant cell), water would actually leave the roots of the plant to bring down the concentration outside. By the way this whole process is called osmosis. In an RO filter water is mechanically forced through a membrane to yiled pure water on the other side, like a filter) So by keeping the ppm down in our fertilizers, the water enters the plant on its own accord, through osmosis driven by a water potential difference. This is why when you cut a stem, xylem sap oozes up for a littel bit from the wound. This is caused by root pressure from the water entering the root cells.
However, this is a minor part of what makes water move through a plant. The main way is through transpiration, and is analogous to a straw. Water holds to itself real well, and displays capilary action. This allows us to hold the top of a straw and not ave the soda spill onto the table until you get it in your mouth. Same idea. When you let go of the straw, the water column is broken (because air got in) and the water falls. In a plant, when water evaporates from the leaves at the top of the plant, it pulls water up through the entire plant. Kind of crazy when you think of a redwood. In essence though, the xylem (wood) of a plant is basically a big straw, always filled with water. When there are breaks in this system though it causes air bubbles in the water column, and the plant has to close of certain areas so the whole straw doesn't unload. Anyway, as the evaporation happens from the top and all the water is moved up, the column is continuous down to the roots, and even into the soil, so this also pulls water through the membrane and into the roots. In a nutshell, there you haveit.

Ions and uptake: All the fod plants eat are ions. Either positive or negative. In soil (which is negatively charged) the positive ions stick to the soil mycelles according to ionic strength. (a proton will knock anything off, and replace it, Mg will replace Ca, and so on. They go in order by periodic table) The negative ions always stay dissolved in water, so when you have water coing out of the bottom of your pot, it is holding mostly neg. ions. In hydro they are always in solution. The plant needs to get these ions, so it used an ion exchange system. In order to grab (for example) a NO3 ion, it needs to have that NO3 come in contact with a special NO3 transporter. Then this needs to be transported over the membrane, which is powered by a proton being pushed in the other direction. (this is EXTREMELY simplefied) THis is why plants lower the pH of the medium they are in over time, becuase they are exuding protons to get the nutrients. Other ions aren't so large, so they have specifc channels that they can pass through membranes in. The plant selectively uptakes what it wants, and even deposits things in the soil for later use (TCA acids, ascorbic acid, etc.) This is a very simplified view of ions and nutrient uptake.

Anyway, in short, water flow and nutrient uptake are quantitatively unrelated. Water goes because of water potential and transpiration, nutrients go because the plant actively recruits them. Too many ions though can draew the water out of the plant, disrupting the water column, and drying it out (nutrient burn).

Hope this helps, sorry for the length

hempgirl

bg, thanks for all that. I work with RO's as well, I test for chlorine and other impurities. we use 10 in membranes in 4 ro vessels so I can understand the way it works as far as ppm and forced through membranes. I didn't know it takes out ions though. it all makes sense to me as far as the protons, neutrons, positive, negative taking eachother and bumping out what they don't need to be neutral.

so then basically the water with less ppm will take to the roots with a higher ppm, but if the roots are higher ppm then they won't take the water (repell) and the soil will soak it up based on the amount of negative and positive neutrons and protons? am I on the right track?
ok then if ro water isn't the same ans DI water, how do you get the DI water? I assume after the RO membranes have their way?
don't worry about the length, like organic stated they don't have to read it.. I want to know so your info is appriciated..
hempgirl

__________________
let's all have a toke
and we'll be alright