Hi does anyone know if Desiccant Silica Gel that you get in things you buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?
Thanks Tricia

"Tricia" wrote in message
...
Hi does anyone know if Desiccant Silica Gel that you get in things you buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?
Thanks Tricia

It isn't.

Silica 'gel' isn't a gel, it's a solid crystal.

Mary

In article , "Mary
Fisher" says...

"Tricia" wrote in message
...
Hi does anyone know if Desiccant Silica Gel that you get in things you buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?
Thanks Tricia

It isn't.

Silica 'gel' isn't a gel, it's a solid crystal.

Until it gets saturated with water, at which point I expect it's
quite gel-like.

On Tue, 8 Feb 2005 19:40:32 -0000, "Tricia"
wrote:

[Is] Desiccant Silica Gel that you get in things you buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?

I've never heard of silica gel being added to compost, and I can't
think what good it would do.

The stuff in compost is either vermiculite (white, porous, dusty) or a
polymer (softer, maybe clear, no dust). Neither works as an effective
dessicant for the air.

Silica 'gel' isn't a gel, it's a solid crystal.
Until it gets saturated with water, at which point I expect it's
quite gel-like.

Not the indicator gel type at any rate (the sort that goes pink when wet)
- stays crystalline

--
Please add "[newsgroup]" in the subject of any personal replies via email
--- My new email address has "ngspamtrap" & @btinternet.com in it ;-) ---

Rob Morley wrote:

Silica 'gel' isn't a gel, it's a solid crystal.


Until it gets saturated with water, at which point I expect it's
quite gel-like.


Nope, not even when it's wet as a really wet thing.


--
Grunff

Colin Wilson wrote:

Not the indicator gel type at any rate (the sort that goes pink when wet)
- stays crystalline


This is just silica gel with added indicator.


--
Grunff

"Rob Morley" wrote in message
...
In article , "Mary
Fisher" says...

"Tricia" wrote in message
...
Hi does anyone know if Desiccant Silica Gel that you get in things you
buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?
Thanks Tricia

It isn't.

Silica 'gel' isn't a gel, it's a solid crystal.

Until it gets saturated with water, at which point I expect it's
quite gel-like.

No, it's still solid when it can't absorb any more water. That's why
sometimes it has a colour indicator added to let you know when it's
saturated.

It's easy to refresh in an oven. But it's never a gel and I wondered why it
was called that when I first used it fifty years ago in the lab.

Wondeful stuff - but never, ever lick it!

Mary

On Tue, 8 Feb 2005 20:54:38 -0000, "Mary Fisher"
wrote:

Wondeful stuff - but never, ever lick it!

Silica gel is lickable, although I'd hardly recommend it.

However _never_ lick the "crystal" cat litter (an acrylic polymer
absorber). Good stuff though, if you have an older cat that's gone
particularly pungent.

DAMHIKT ....

"Andy Dingley" wrote in message
...
On Tue, 8 Feb 2005 19:40:32 -0000, "Tricia"
wrote:

[Is] Desiccant Silica Gel that you get in things you buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?

I've never heard of silica gel being added to compost, and I can't
think what good it would do.

http://www.crystals.us/WSWaterSmart.htm are the crystals that are added to
plant compost, so what is Desiccant Silica Gel made from?

Thanks Tricia

Andy Dingley wrote:
On Tue, 8 Feb 2005 20:54:38 -0000, "Mary Fisher"
wrote:


Wondeful stuff - but never, ever lick it!


Silica gel is lickable, although I'd hardly recommend it.

However _never_ lick the "crystal" cat litter (an acrylic polymer
absorber). Good stuff though, if you have an older cat that's gone
particularly pungent.


so it's ok to lick the non crystal cat litter ;o)

"Andy Dingley" wrote in message
...

Wonderful stuff - but never, ever lick it!

Silica gel is lickable, although I'd hardly recommend it.

Bad news: it absorbs spit so dramatically that it can stick to your tongue -
as I found out to my cost :-(

Good news: it's not poisonous :-)

However _never_ lick the "crystal" cat litter (an acrylic polymer
absorber).

Assuming that you have experience I promise not to do it.

Why on earth would you want to?

DAMHIKT ....

? That's one I don't think I've seen before and can't work it out. Well,
can't be bothered ...

Mary

In article , "Mary
Fisher" says...

"Rob Morley" wrote in message
...
In article , "Mary
Fisher" says...

"Tricia" wrote in message
...
Hi does anyone know if Desiccant Silica Gel that you get in things you
buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?
Thanks Tricia

It isn't.

Silica 'gel' isn't a gel, it's a solid crystal.

Until it gets saturated with water, at which point I expect it's
quite gel-like.

No, it's still solid when it can't absorb any more water. That's why
sometimes it has a colour indicator added to let you know when it's
saturated.

It's easy to refresh in an oven. But it's never a gel and I wondered why it
was called that when I first used it fifty years ago in the lab.

A good question indeed.

Wondeful stuff - but never, ever lick it!

I feel an urge to go find some and try it right now :-)

Tricia wrote:

so what is Desiccant Silica Gel made from?


It is silicon dioxide. It's called a 'gel' because it has a very porous
structure (which is why it's a good dessicant).


--
Grunff

In article , "Mary
Fisher" says...

"Andy Dingley" wrote in message
...

Wonderful stuff - but never, ever lick it!

Silica gel is lickable, although I'd hardly recommend it.

Bad news: it absorbs spit so dramatically that it can stick to your tongue -
as I found out to my cost :-(

Good news: it's not poisonous :-)

However _never_ lick the "crystal" cat litter (an acrylic polymer
absorber).

Assuming that you have experience I promise not to do it.

Why on earth would you want to?

DAMHIKT ....

? That's one I don't think I've seen before and can't work it out. Well,
can't be bothered ...

Don't ask me how I know that.

"Rob Morley" wrote in message
t...
In article , "Mary
Fisher" says...

"Andy Dingley" wrote in message
...

Wonderful stuff - but never, ever lick it!

Silica gel is lickable, although I'd hardly recommend it.

Bad news: it absorbs spit so dramatically that it can stick to your
tongue -
as I found out to my cost :-(

Good news: it's not poisonous :-)

However _never_ lick the "crystal" cat litter (an acrylic polymer
absorber).

Assuming that you have experience I promise not to do it.

Why on earth would you want to?

DAMHIKT ....

? That's one I don't think I've seen before and can't work it out. Well,
can't be bothered ...

Don't ask me how I know that.

poh.

S'obvious, really ... thanks :-)

Thinks - I wonder how he knows it ...

Mary

"Rob Morley" wrote in message

Hi does anyone know if Desiccant Silica Gel that you get in things
you
buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?
Thanks Tricia

It isn't.

Silica 'gel' isn't a gel, it's a solid crystal.

Until it gets saturated with water, at which point I expect it's
quite gel-like.

No, it's still solid when it can't absorb any more water. That's why
sometimes it has a colour indicator added to let you know when it's
saturated.

It's easy to refresh in an oven. But it's never a gel and I wondered why
it
was called that when I first used it fifty years ago in the lab.

A good question indeed.

Wondeful stuff - but never, ever lick it!

I feel an urge to go find some and try it right now :-)

I didn't know I had a child called Morley ... puzzled

Mary

"Tricia" wrote in message
...

"Andy Dingley" wrote in message
...


[Is] Desiccant Silica Gel that you get in things you buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?

I've never heard of silica gel being added to compost, and I can't
think what good it would do.

http://www.crystals.us/WSWaterSmart.htm are the crystals that are added to
plant compost, so what is Desiccant Silica Gel made from?

http://users.adelphia.net/~jthm/info.html

is a nice (if badly spelled) site.

Mary

Thanks Tricia

On Tue, 8 Feb 2005 21:21:42 -0000, "Mary Fisher"
wrote:

However _never_ lick the "crystal" cat litter (an acrylic polymer
absorber).

Why on earth would you want to?

To discover whether it was a super-absorbent polymer or not. It is.

Or rather "If ith" 8-)


DAMHIKT ....

Don't ask me how I know that.

On Tue, 8 Feb 2005 21:19:47 -0000, "Tricia"
wrote:

http://www.crystals.us/WSWaterSmart.htm are the crystals that are added to
plant compost, so what is Desiccant Silica Gel made from?

They're the polymer sort (so not really "crystals")

Silica gel is "fluffy glass". It has an adsorbent surface, so will
adsorb (with a "d") moisture from the air and hold it on the surface
of the beads. Because this just happens at the surface, it's a limited
volume.

Vermiculite is similar, except that it is porous throughout and so can
hold a useful amount of water for a plant's needs. It also has a less
active surface than silical, so it won't adsorb water vapour from the
air. Fuller's earth (if we're talking cat litter) works similarly.

The polymers absorb (with a "b") moisture, the difference being that
it's a volume effect, not a surface effect. They aren't strong enough
attractors to work as a dessicant, but they will absorb a _lot_ of
moisture, hence their use for plants.

If you just need a small quantity of the polymer, cut some disposable
super-dry nappies open.

--
'Ph'nglui mglw'nafh Cthulhu Evesham wagn'nagl fhtagn'

Andy Dingley wrote:

Silica gel is "fluffy glass".

With pores running right through it.


It has an adsorbent surface

The effective surface being far greater than the external surface area
of the granules.

so will
adsorb (with a "d") moisture from the air and hold it on the surface
of the beads.

Typically several hundred square metres per gram.


Because this just happens at the surface, it's a limited
volume.

Well, it's a finite volume, certainly, but it's pretty high.



--
Grunff

On Tue, 08 Feb 2005 22:50:16 +0000, Grunff wrote:

Silica gel is "fluffy glass".

With pores running right through it.

Depends on the grade. The stuff used for dessicants is pretty low-spec
stuff. Although there are "pores" going deep, the
high-surface-per-volume portion is just an outer skin.

In article , "Mary
Fisher" says...
snip

I didn't know I had a child called Morley ... puzzled

Mum?

"Tricia" wrote in message
...
Hi does anyone know if Desiccant Silica Gel that you get in things you buy
to absorb moisture is the same silica gel that is sold as a moisture
retaining aid in potting compost?
Thanks Tricia

From the replies and the research I have done it is not. Pity as I work in a
shop where the Desiccant Silica Gel is in all the packaging and it is just
thrown out. I will just have to buy the other stuff for my hanging baskets.

Tricia

"Rob Morley" wrote in message
...
In article , "Mary
Fisher" says...
snip

I didn't know I had a child called Morley ... puzzled

Mum?

No!

(I've never seen this man in all my life, m'lud. He's not my responsibility.
I'm not paying any of his fines or charges or fees.)

Now go away and tidy your room you little *******!

AND STOP LICKING THOSE LITTLE BEADS!

In article , "Mary
Fisher" says...

"Rob Morley" wrote in message
...
In article , "Mary
Fisher" says...
snip

I didn't know I had a child called Morley ... puzzled

Mum?

No!

(I've never seen this man in all my life, m'lud. He's not my responsibility.
I'm not paying any of his fines or charges or fees.)

Now go away and tidy your room you little *******!

AND STOP LICKING THOSE LITTLE BEADS!

mmmffh grrrrkk rrrrrr

"Rob Morley" wrote in message


AND STOP LICKING THOSE LITTLE BEADS!

mmmffh grrrrkk rrrrrr

Serves you right.