Killed some root growths on my Paph...

[The Mutant]

Originally Posted by camille1585

Total disolved solids is not always given as ppm or mg/l. On the water report of my town it is given in mS/cm, which is a measure of conductivity, and it is called such on the report. There is a calculation you can do to convert that to ppm.

Thanks Camille, I found it now! It's called the same here in Sweden but it's given in mS/m, so here in my city the conductivity is 250 mS/m, I'll check what it could be in ppm. Oookay, first I'll have to figure out what it might be in mS/cm? And me who sucks at math!

Is it 0.25 mS/cm? Or is it 25000 mS/cm? I've no idea if I'm supposed to count up or down!

Okay, if it's the first one, 0.25 mS/cm, I think it might be 160 ppm, if it's the second alternative the ppm will be 1600000000... Which seems a bit ridiculous... So I guess it's the first one then.

Originally Posted by King_of_orchid_growing:)

The idea that orchids don't like Ca much is an overgeneralization.

Certain orchids actually grow on limestone in the wild! Particularly certain types of Paphs and Phrags.

Some prime examples of Paphs and Phrags that grow on limestone outcroppings are:

Paph armeniacum
Paph emersonii
Paph malipoense
Paph micranthum
Paph niveum
Paph stonei
Paph vietnamense

Phrag fischeri
Phrag kovachii
Phrag schlimii

There are hosts of others as well, but I'm not too familiar with them.

Yes, I know this too. So far I haven't managed to order one of the calcicolous Paph species, although I've gotten some mixed information regarding Paph. purpuratum.

I'm sorry, when I talk about orchids I tend to think about Phals - I always forget that there's so many more genera than Phals and Paphs.

[camille1585]

The conductivity of my water is actually also in mS/m. Mine is 17 mS/m which I had calculated to be a TDS of about 100ppm. The conversion is only an estimate, and according to internet 100 mS/m = roughly 550ppm TDS

So 250 mS/m (= a bit under 1400ppm) sounds huge!! What's the hardness at? (measured in °D, ppm, mg/L dGH, or °dH)

[camille1585]

I'm wondering if such a reading is even possible.... Did you make a typo and write 250 instead of 25?

[camille1585]

Or maybe I've got the conversion wrong, because apparently drinking water is considered safe under 500ppm.

[The Mutant]

Oh, I think I looked at the wrong column, it's supposed to be 15-17 mS/m and nothing else... Oops, sorry...

The hardness is 2,9 - 3,1°dH.

[camille1585]

Whew! You scared me!
So your water is like mine, it terms of TDS and hardness.

If you are interested, these are the conversions I found on internet:
17 mS/m = 0.17mS/cm
To get the approximate TDS: 0.5 (or 0.7) * 1000 * the EC (in mS/cm)
0.5 and 0.7 are both valid, it some TDS meters use one, others use the other.

[The Mutant]

I scared myself!


Remind me NOT to read any documents that require more than 0,1% brain capacity when I haven't slept enough the night before.

The only weird thing about the water is that the pH levels are pretty high, 7,8 - 8,4, despite the rather low dH levels. I've always thought that one kind of excludes the other like, high pH levels equals high dH levels, but this doesn't seem to be the case...

Thanks for the conversions!

[camille1585]

My pH is 7.9....
pH can also be influenced by the amount of CO2, hydrogen ions in the water. Other than that, I don't know what the science is behind soft water with high pH, I also thought it would be acidic. My tapwater in France is soft and acidic.

[james mickelso]

I am 0one of those who waters by dipping. I can't afford to do it any other way. And my greenhouse set up is such that the orchids on the top shelves just water the ones on the lower shelves anyway. I started watering with a hose and it wasn't too long and I had all kinds of fungus and bacterial rot on my babies. So I switched to dipping each one and it has worked very well. No problems although part of the equation is that I water just enough to keep them happy. And I have installed a good fan which dries everything out quickly. I get nearly everything from donation tables at shows and club meetings. I( have around 200 orchids in various shades of growth. One of the biggest differences in my cultural exercizes is I now water with DI or RO water. I buy 4 gallons of either and warm it up with weakly fertilized hot tap water. Temp is around 75*f when I emerse my babies. I emerse them just up to the lip of the pot. Rarely do I get the foliage wet. That would spread whatever disease, fungus, or fairy poop that is on the leaves. So far (8 years) I haven't had any problems. Except when I kept them all too wet.

[Leafmite]

So, concerning calcium, what do you do with crosses where one parent loves calcium and the other doesn't?

I also share water between my orchids, now. Saves quite a bit of money, time and effort. My water goes through a water-softner as it is very hard so it is useless for my plants. I have to buy water when the dehumidifier or clouds don't provide enough. When I was very careful and not sharing water, I lost seven orchids to black rot and realized all these diseases can spread in other ways, anyway. The new orchids are watered seperately but the others have had plenty of time to infect each other.