Do you adjust pH when watering?

[IdahoOrchid]

Originally Posted by rsfrid

Culligen (and, presumably others) will do it for free. Of course you realize their motive is to sell (or rent) you a unit. But it may be worth it if you want that info bad. And who knows, maybe you'll want a new RO unit

Culligan would have no incentive to sell me a new softener or RO unit as I have both and the came from Culligan two years ago. Other than the inconvenience of the hard water deposit chips in the water line it has been a great investment. The dishwasher was so caked with deposits (and smelled) that Renee did not want to use it. I convinced her it was just hard water and now two years later about 50% of it is gone.

I did take a sample of our RO water to Culligan and they tested it at 27 on the two year old membrane.

I just called our Culligan sales lady and she will be stopping by tonight to do some testing. She cannot test for the individual components but will test our hardness and TDS for us again. She said the other testing would be $50.

UPDATE

Tests just completed.

Outside hardness is 20 grains, inside (post softener) 1 or less.

Outside TDS is 550, inside 680, RO 40. Like I said, the test with the meter at the store was 27. That is a rejection of about 95% after two years.

She did a PH test on our RO water, but it was one of those change the color and compare ones. It appears that our RO water is something less than 6.2 but I am still not sure. Once I saw what kind of test it was I did not even ask for the outside water to be tested.

[Jerry Delaney]

I probably shouldn't jump in here as I am about as far away from being a plant nutritionist without stepping off the face of the earth. However, that said, I keep seeing the term "pure" water. "Pure" water, say in the 1 million mega ohm range, is nearly impossible to accurately pH. There must be some dissociated ions in solution in order for a pH meter to accurately measure the pH. "Goodgolly" is correct in stating that a meter must be calibrated at two pH levels to calibrate properly, i.e. pH 4 & 7 being most commonly used. Most pH probe manufacturers will tell you to NEVER store the electrode in distilled or deionized water. They should be stored in a solution designed for that purpose or in pH 4 buffer. Also, if one is going to use a pH meter that does not possess manual or probe temperature compensation, you should make sure that the buffers used to calibrate the meter and your test solution are at the same temperatures.

[Ray]

A comment about the TDS of fertilizers and my online calculators. In the horticulture industry, the vast majority of folks us electrical conductivity (EC), not TDS. TDS meters are simply cheap EC meters with a built-in conversion to solids content. As conductivity changes with the actual ionic species in solution, their concentrations, and as Goodgolly pointed out, with temperature, how can a single conversion factor be correct all the time? I recommend that folks use TDS meters as reference only, not for absolute values. I have two, and they give me entirely different readings at for the same solution: TDS and EC.

As to the calculators at my website, they are only for rough approximations. Let me explain why.

As was stated above, if you use a teaspoon per gallon of the Greencare Orchid Special for Pure Water (MSU RO), which is a 13-3-15 formula, the TDS calculator says you'll add 353 ppm of dissolved solids to your water, but that's only based upon the N, P, & K. If you calculate the TDS based upon the masses of all of the elements listed on the label, you get something like 487 ppm TDS. However, as the label also stated at one teaspoon weighs 4.3g, if I add that to a gallon (3785g) of water, I have really added 1136 ppm!

I'll grant you that there are components of the various minerals used to make up the fertilizer that don't add to the measured value (oxygen and hydrogen, or water of crystallization for example), but without knowing the exact mineral formula, how are we supposed to know "for sure"?

I, like Goodgolly, prefer to find something that works and stick with it until some improvement comes along. I don't measure my pH or EC on a regular basis, I just mix up the same chemistry in the same ratios and occasionally do a spot check to verify that I'm still in the right range.

One last thing: Goodgolly - if you look at the Greencare label, you will see that the 0.09% sulfur in the formula is all from sulfates (Cu-, Mn-, and Zn-). I have great faith in Bill Argo (the PhD who came up with the formula) to know a great deal more about plant nutrition than I could even imagine, so with that in mind, it seems that sulfuric acid - other than for the potential safety issues - might not be a bad choice for pH lowering. We use Epsom Salts as an additive, too, and it's not "just" for the magnesium, so maybe the sulfate ion isn't a bad actor, after all. (Just supposition, but it seems logical.)

[Jerry Delaney]

I think that Ray has summed it up quite well when he stated that he just finds something that works and sticks with it. Murphy's law of "if it's working, don't mess with it" really comes into play here. I personally do not measure the pH of the water or fertilizer mixture. Nor do I measure the TDS in the water except for the couple of small trays of Disas. Otherwise, I use tap water for everything else. I depend upon my plants to tell me if they need something different. For example, when I start to see leaf tip die back on my Phrags, I'll start worrying more about the TDS of the water I am using. Maybe we all worry too much about the chemistry of things instead of just working toward what gives us the results in plant growth and blooming we are happy with. We used to have a saying in my industry that says "it's been proved that if you take a biological organism and place it in a carefully controlled environment under carefully controlled conditions, it will behave as it darned well pleases".

[Ross]

Originally Posted by Jerry Delaney

I think that Ray has summed it up quite well when he stated that he just finds something that works and sticks with it. Murphy's law of "if it's working, don't mess with it" really comes into play here. I personally do not measure the pH of the water or fertilizer mixture. Nor do I measure the TDS in the water except for the couple of small trays of Disas. Otherwise, I use tap water for everything else. I depend upon my plants to tell me if they need something different. For example, when I start to see leaf tip die back on my Phrags, I'll start worrying more about the TDS of the water I am using. Maybe we all worry too much about the chemistry of things instead of just working toward what gives us the results in plant growth and blooming we are happy with. We used to have a saying in my industry that says "it's been proved that if you take a biological organism and place it in a carefully controlled environment under carefully controlled conditions, it will behave as it darned well pleases".

Jerry, this is probably one of the best responses I have seen thus far on any topic. While I have chosen to measure certain things, and provide certain controlled measures of nutrients, those darned orchids insist on doing their thing! I have made one change over the last year that has made a singular major improvement - controlled nutrient provision. Based on stuff I read here and Ray's info, I moved over to constant 125ppm Nitrogen MSU mix with RO water and I saw an improvement that was awsum. I was testing the pH and will do so again after I receive my new meter, but overall, the 'chids are doing so well I wonder why I bother

[Jerry Delaney]

Yeah, it seems that every day that goes by, mother nature provides a lesson that shows just how dumb I really am!!

[goodgollymissmolly]

I'll probably catch some flack on this because everyone sees this subject in their own way. I am not sure that I agree with the position that says "don't worry too much about a bunch of measurements just continue your successful methods".

Before I walk the plank on this, I want to respond to a couple of Ray's points. He is totally correct in saying TDS is a method that leaves a lot to be desired. It is much easier for most people to understand ppm of dissolved solids than micro Siemens per cm (which was micro mhos per centimeter when I learned in the 15th century). Unfortunately, there is no direct functional relationship between the two.TDS is a contrived term that assumes electrical conductivity is completely made up of ions with a charge of 1 electronic unit (if you wish, ions with a valence of 1). Sometimes it is called sodium chloride equivalents. EC is the actual measurement of the solution conductivity. However, if you are always doing the exact same measurement,as we are, then TDS is a perfectly good way to compare results over time.

Ray's second point was about the use of sulfate ion. Apparently sulfate ion is not harmful (at least in small quantites) to plants. I read that potassium sulfate is sometimes used to provide the potassium in fertilizer. I have seen nothing that suggests sulfate is good or what kind of limits might apply, but Ray is right that sulfate in some concentration is not bad and sulphuric acid might be used as a pH down agent.

Now back to the cow pie. I read a lot of books...every one that I can get my hands on. Currently I'm reading a book that was highly recommended in the Oct,Nov,Dec 2004 Cattleya edition of Orchid Digest. It's called American Cattleyas by Courtney T. Hackney. I have never seen this book mentioned anywhere else. It can be bought from Orchid Books and if you are interested in Catts, I recommend it. The author interviewed all the old time Catt specialists and covers everything from the most important species (to hybridization) to cultural recommendations and much more.

So to the subject of measurements. The author summarizes my feelings about plant quality better than I ever could. He says in relation to plant quality, "The answer is easy, obtain healthy, vigorous clones and grow them to perfection by providing just the right amount of light, water, and fertilization, the correct growing medium at the ideal temperature............It is not uncommon for the exact same plant grown by different people under different cultural conditions to have flowers that differ sunstantially in size, color, and form......Mastery means not just growing and flowering a plant, but flowering a plant to its full potential"

So I ask three questions:
Assuming that you can determine from somewhere the perfect cultural conditions, how do you plan to measure whether you match them unless you make measurements?

Second, assuming you achieve ultimate perfection and something goes wrong, how do return to perfection unless you can measure and correct whatever is wrong?

Third, no matter how much you enjoy and admire your plants, how do you know that you are the best grower around unless you compare your results with the results of others? Just an isolated "they suit me" is not enough.

OK, let the hell rain!!

[Jerry Delaney]

You won't catch any flack from me "Goodgolly". I learned a long time ago that if a person has heard about something, they have an opinion about it. That being said, often a persons thoughts about a certain subject doesn't necessarily make them right or wrong, just opinionated. You are allowed to have an opinion just like everyone else! As to perfection, I doubt that even mother nature provides "perfect conditions" much of the time and especially now that mankind has kind of messed up conditions around the world. I guess my response comes from having been in a scientific field all my working life. Growing orchids to me is strictly a hobby. At this stage in my life, I simply do not have the desire to to make my hobby a scientific study. There is only one person my orchids have to satisfy; ME. So, that being said, you are certainly entitled to your opinions and this topic certainly makes interesting reading. I am more or less an old has been that enjoys throwing a wrench in the moving gears just to see what happens. Hang in there! It's persistent people like you who strive for perfection that move the world!

[Ray]

Originally Posted by goodgollymissmolly

Assuming that you can determine from somewhere the perfect cultural conditions, how do you plan to measure whether you match them unless you make measurements?

I think you're just taking it to a different - not necessarily better - level.

If I have found through measurement that when I dump a 25# bags of MSU RO fertilizer in my mixing drum, then fill to the 50-gallon mark, and feed that solution through my proportioner, I have exactly what I'm after, why do I need to measure them every time I repeat the process? Yes, it's possible the proportioner is off a bit, but if I have found, after many repetitions with testing, that it is stable, permitting myself the luxury of skipping a test every now and then, and it is not an issue.

Originally Posted by goodgollymissmolly

Second, assuming you achieve ultimate perfection and something goes wrong, how do return to perfection unless you can measure and correct whatever is wrong?

Unless you grow only a single plant, there is practically no way to reach "perfection" in your culture. What might be ideal for one is probably a shade off for another, and totally unacceptable to a third.

Originally Posted by goodgollymissmolly

Third, no matter how much you enjoy and admire your plants, how do you know that you are the best grower around unless you compare your results with the results of others? Just an isolated "they suit me" is not enough.

This comment demonstrates a significant difference in philosophies - and that's not a "bad" thing, just a different way of looking at things. I have never sought to be "the best" grower. My goal is to do what's right for the plants. More often than not, if I do a good job at that, the results tell.

[bodaciousbonsai]

I use a freshwater fish tank ph test kit. works great!