Ok, so after investing in phrags pretty heavily, I want to work on providing the best possible water. I am using distilled water, fertilizer formulated for pure water and applying it before the mix begins to dry out. So I feel pretty comfortable with my watering schedule.

How do I test the PH of water?
What PH do besseae and besseae hybrids like?
How do you make water more acidic, more basic?
Should I even start down this road, or should I just stick with distilled water, my fertilizer and move on with my life?

As a bonus question, can long term low humidity (30-40% RH) hurt the orchids? I have a serious problem increasing humidity even with a humidifier running 24/7. Arizona is dry!

I'm interested to hear the pH preference of besseae complex myself :confused: . As to the pH of distilled water, it should be 7.0 (neutral) if its true distilled, and it should be soft (low mineral content). You can purchase extremely accurate pH test kits, and meters, at any good pet shop that has a good aquarium department.

Mark

For pH: You can get a test kit for fish aquariums and it will give you a pretty accurate idea of your water quality.

Besseae and hybrids: I will let some experienced besseae growers answer this one. I have a few hybrids but I don't grow any species besseae. I think you are pretty safe watering with plain distilled water, but be careful with the fertilizer because adding it will change the pH and hardness of your water.

To make water more acidic you can add things like lemon juice or vinegar. I have never actually done this, so again I will let the true besseae growers get into that.

Long term humidity can be a huge issue. Slippers pretty much like a steady humidity of 70%. They can tolerate occasional fluctuations but you do need to have a plan in place to increase ambient humidity. Humidity trays are probably the easiest, cheapest way. Dips in humidity probably won't kill your slippers, but they won't thrive.

I hope this helps, I have learned most of my besseae info from trial and error, and error, and error....

*edit* what's in your water is also something you should be concerned about. My tap water is pretty hard (calcium ppm of 250-300). You can measure it with a tds meter, but it won't necessarily tell you if your water is hard or just salty (thanks RickL!). Your best bet is to get a free water quality report from your water company (this is a better way because it tells you what kind of solids are in your water). I got a report online and found out my tap water gets almost all of its solids from calcium (I have aquifer water). This explains why my paphs love it. With phrags you pretty much have to water with distilled, r/o, or rain water. Fertilizer should only be added very weakly.

During our trip to Ecuador in May, 2005, we were able to sample water seepages in five different habitats of Phrag. besseae. The plants grew in extremely wet conditions, in pockets of moss and decaying vegetation on granite rock cliff faces and the humidity was always high. The average seepage pH was 6.8 - slightly acidic- and the average dissolved solids readings of the seepage was 18.0 micro-siemens. This is very pure water, and I am guessing the primary source of nitrogen to be amine compounds secreted by the roots of the moss. This would indicate to me that P. besseae is a very light feeder in habitat.

Best Regards,

Tom

Tom...do you by any chance know a conversion from micro-siemens to ppm?

Thanks, Chuck

Just a quick follow up to my question to Tom...

I did a Google search for micro seimens and found this:

"How do I convert between TDS and EC readings?

Answer: To obtain an approximate sodium chloride TDS value, multiply the EC reading (in microSiemens/cm) by 1000 and divide by 2.

To get an EC value, multiply the ppm reading by 2 and divide by 1000.

Thus, if your EC is 1:

1*1000/2= 500 ppm.

And if your ppm is 500:

500*2/1000= 1 EC"

I wonder if I can get Tom to comment on this example

Thanks
Chuck

Hi Chuck,

Micro-siemens-to-TDS conversion is a complex subject, because each dissolved solid in your water has it's own particular conversion factor. To be technically accurate, you would have to determine what minerals are present and then average all of the conversion factors to get the actual number. No one I know actually does this - at least to determine irrigation water quality.

For general purposes, however, we use a 0.55 conversion factor. i.e. 1,000 uS = 550 mg/L TDS. Personally, I think this is as close as you need to get. For more information, Bob Wellenstein has an excellent writeup of this subject online at the AnTec website.

Hope this helps!

Tom

Tom,

Thanks for the prompt reply. I'm sure that your approximation is close enough.

It's amazing how pure the seepage water for the wild besseaes was considering that our city water has around 30 times that amounnt of dissolved solids and our water is considered good.

Chuck

18 useimens won't tranlsate to allot of TDS no matter what conversion factor you use.

So distilled or RO water is a good choice for most irrigation water needs for bessea.

I use RO water as my base water for fertilization and regular irrigation.

As noted the pH of pure water is 7, but it will generally read less than this with pH meters because they have problems reading solutions of low ionic strength, and a slight balance of CO2 in the water converts to carbonic acid, and tips the pH toward the acidic side.

I fertilize with MSU fert and add superthrive, and that mix comes out with a pH of about 4.0 in RO water. I subsequently have to raise the pH to 6.5 with potassium hydroxide (Protekt). (This is reccomended on the Antec site). At this point I haven't had a need to lower pH, but vinigar seems to be pretty popular for this purpose.

Tom's right about conversion of TDS and conductivity. As noted in Chuck's response that conversion is for NaCl, and doesn't work well at all for salts of divalent cations such as Ca and Mg The true method of determining TDS is to evaporate off the water from a known volume of sample, and weigh the residue that remains. If you are on a municipal water supply then you could ask for the water reports from the health dept or city opperations in charge of the water plant and TDS is one of the parameters that should be available.

But at this point I'd worry more about my low humidity than the pH of my irrigation water. You need to seal things up Frank, and get a bigger humidifier.

Tom,

Thanks for the prompt reply. I'm sure that your approximation is close enough.

It's amazing how pure the seepage water for the wild besseaes was considering that our city water has around 30 times that amounnt of dissolved solids and our water is considered good.

Chuck

Its a matter of geology. Granite is fairly impervious to rain water (compared to limestone or sandstone) so its not uncommon to see low TDS (and often lower pH) waters coming off of shallow aquifers that are granite based.

Hi,
So I tested the pH in my new house yesterday and it is 9!! :shock:
Am I correct in assuming that I can adjust this using fertilizer and superthrive and the plants will be okay? I have a LOT of besseae hybrids/species to be concerned about.

Also, how does one go about finding out if one's water is softened? Is pH ever an indicator of this?

Thanks in advance!
(H, freaking out over her water this morning...)

Hi,
So I tested the pH in my new house yesterday and it is 9!! :shock:
Am I correct in assuming that I can adjust this using fertilizer and superthrive and the plants will be okay? I have a LOT of besseae hybrids/species to be concerned about.

Also, how does one go about finding out if one's water is softened? Is pH ever an indicator of this?

Thanks in advance!
(H, freaking out over her water this morning...)

Heather,

You can probably get a water report for your area online and it will tell you everything that is in your water, and give you a breakdown concentration of each, and will give you an indication of sodium in your water and general hardness. I know Superthrive will lower your pH, so if you are planning on using it with every watering then that might solve your pH problem, but alot of people don't like to use ST all the time.

As far as water softeners...look around your house for a big tank marked "water softener." Most of them in my area are installed by Culligan and it says "Culligan Water Softener" right on it. My friend's tank is in her garage where the hot water tank is. I think they also make under the sink varieties.

If all else fails...collect rainwater! That's what I have started doing because my r/o filter is not working properly :roll:

Hi Heather,

A couple of things. First, if you aren't softening the water, make sure the municipal pumping station isn't doing it without your awareness. I ran into this situation way back when I started growing orchids in La Grange, IL. I just could not get anything to grow, let alone bloom. I read everything there was to read about orchid culture - did everything by the book - and still couldn't grow them. It wasn't until I requested a copy of the water analysis from the village that I realized the sodium levels were way above what one would expect from groundwater. A simple phone call to the village water dept, confirmed that they were 'pre-softening' the well water with a sodium zeolite softener before pumping it out into the distribution lines. A quick change to collecting rainwater, and I was off and running. I still think rain water is the best if you have away of collecting it. Otherwise, a small RO system works fine.

It's really important to get this water analysis from your municipality before deciding on how much fertilizer/additives, etc. to add, since the total dissolved solids levels of your water supply will have a lot to do with how much you feed, and how frequently.

The thing about Phrag. besseae, is that it's a great indicator plant - if you're watering correctly and repotting annually, and the leaf tips are still turning brown, then the TDS of your water supply plus fertilizer and additive, is probably too high. It's also a good idea to invest in a conductivity meter to check these things for yourself. Cole-Parmer sells basic TDS/EC meters for about $ 70 and they are easy to use. As a general rule, Phrag. besseae grows best when the TDS of your irrigation water, including fertilizer, doesn't exceed 100 mg/L - or roughly 180 uS. As far as pH is concerned, try to shoot for 7.0 plus or minus 0.5 for best results.

Best,

Tom

Thanks Tom and Teresa!

So far, since we only moved in on sunday, I have not yet located a good place to collect rainwater. Need to investigate the back yard which we share with the two other tenants.

Tom-i have a combined hannah tds/pH meter and it look like my salts were not to high when I checked yesterday, but I have a hard time inerpreting them. I will check again later today when I get home and post my results. Maybe you guys will be able to help me understand better what I have going on.

Okay, so here's the numbers:

pH is 9.28 (ack!)
mS is .21 (is that conductivity?)
ppt is .10

Any thoughts would be graciously appreciated!! Thanks!

Heather,

The pH is too high, esp. for Phrag. besseae (which you already knew). Try adding 1/8 tsp of your fav orchid food to a gallon of your tap water, and then check the pH again. It should come down. Then try adding more fertilizer in 1/8 tsp/gal increments, up to 4. This will give you 4/8 or 1/2 tsp/gal - and keep a log of your results. This will pretty much tell you the effect on pH of different fertilization rates in your particular water supply. It's also a good idea to check the conductivity with each of the 1/8 tsp/gal additions, as your readings should go up pretty quickly. I'm guessing that your preferred rate for P. besseae is going to be about 1/8 tsp/gal.

As far as the conductivity reading, it's not bad. 0.21 mS equates to 210 uS ( 1 mS = 1,000 uS). Since the conversion factor is 0.55 your TDS equates to 115.5 mg/L (or ppm). Not bad, really.

I have no clue what the .10 ppt means. I assume it mean parts per trillion of something. Whatever it is it, it's way too low to be causing problems - at least for your plants. You might give them a call and ask, though.

Hope this helps!

Best, tom

Thanks Tom!
I think (tho I could be wrong) that the .10 ppt is parts per thousand and corresponds to the TDS - it lists that reading as EC/TDS in the manual. Not sure?

At any rate, it sounds like I don't have a problem w/ water softener (as the salts would be much higher, right?) but that the pH definitely needs to be dealt with. Well, that's an easier fix, if you ask me. If I can use tap w/ fertilizer adjusted for three waterings and flush w/ distilled or rain (when I can get that going) once every fourth, I think I'll be okay. I need to try to get away from buying distilled for every watering - too expensive and too many stairs in the new house!

Thanks very much for your help with the math - I am not so good at all the conversions. I really appreciate it. :)

It sounds like you have a pretty decent water supply except for the pH. The best indicator of whether the TDS is acceptible for P. besseae will be the non-browning leaf tips. FYI - we normally fertilize our P. besseae's at 1/8 tsp/gal of 15-5-15 every third watering; the other two waterings are plain water. We use rain water when it's available, with RO supplement if we have a dry spell, plus a small addition of well water for the micro-nutrients. The whole thing comes out to about 100 uS EC for plain water, and about 250-300 uS when we fertilize.

PPT is parts per thousand, so if you slide the decimal point to the right 3X you convert it to ppm, which is roughly equivalent to mg/L.

0.1ppt = 100ppm or about 100 mg/L.

The high pH may be due to a gas imbalance issue. Try aerating it overnight and see how it comes out.

When I lived in OK the tap water had a pH of 10 to 11 fresh off the faucet. Lots of alklinity with high O2, but not much hardness, so the pH wasn't stable. After aerating overnight the pH fell to mid 7's.

Also if you use as much ST as I do, there would be a good chance that it would take the pH to about 7, but try aeration first, and Tom's suggestions before other acidification measures.

Okay, great - That's what I thought about PPT, thanks Rick.

So, by aerating (sorry, I'm so dumb) you mean just letting it sit out overnight? Like I would for a fish tank water change? Or would I need to stir it around occasionally or something? Just want to be sure I am under standing correctly. That would be great if that was all it took.

Thanks again guys!

Okay, great - That's what I thought about PPT, thanks Rick.

So, by aerating (sorry, I'm so dumb) you mean just letting it sit out overnight? Like I would for a fish tank water change? Or would I need to stir it around occasionally or something? Just want to be sure I am under standing correctly. That would be great if that was all it took.

Thanks again guys!

Unfortunately a bit more than that. I meant with an aquarium airpump with an air difuser in the water.

This thread was very enlightening and gave me hope for my limp dying phrags. I need to cut back on my fertilier, I thought heavy, and increase the humidity. Thanks so much for ALL the comments and especially the TDS and pH comments.
Eternally in your debt!:D

Unfortunately a bit more than that. I meant with an aquarium airpump with an air difuser in the water.


Well, I knew it couldn't be that easy. :poke:
okies, thanks, Dr. Rick!