To flush LECA medium with tap water or reverse osmosis water?

[Ray]

Aw, c'mon now, OW. Now you're getting pickier than me!

I suspect that a lot of this is due to English not being the author's primary language, but in that questionable "dictionary", they state that "permanent hardness is caused by the presence chlorides, nitrates and sulphates of calcium and magnesium, which will not be precipitated by boiling", while every other water quality text I've ever seen says that it is calcium-, magnesium-, and iron carbonates. They go on to contradict that with their "lime scale" comments in the same paragraph.

They also describe that boiling does not get rid of temporary hardness; it changes it into permanent hardness!

[Orchid Whisperer]

Originally Posted by Ray

Aw, c'mon now, OW. Now you're getting pickier than me!

I suspect that a lot of this is due to English not being the author's primary language, but in that questionable "dictionary", they state that "permanent hardness is caused by the presence chlorides, nitrates and sulphates of calcium and magnesium, which will not be precipitated by boiling", while every other water quality text I've ever seen says that it is calcium-, magnesium-, and iron carbonates. They go on to contradict that with their "lime scale" comments in the same paragraph.

They also describe that boiling does not get rid of temporary hardness; it changes it into permanent hardness!

Ray, that just happened to be the first description of permanent vs temporary hardness I came across at zero-dark-thirty in the morning while getting ready for my morning commute.

The concept is well known. So-called "temporary hardness" is associated with precipitation and scale formation, which can be induced by boiling, the remaining water will have lower hardness. It is associated with Ca and Mg bicarbonate (the Wikipedia page on hard water describes the chemistry in general terms, and also describes the difference from permanent hardness). My point is the OP was correct in saying some hardness can be removed by boiling; it depends on what minerals are dissolved that contribute to the hardness.

[Ray]

Originally Posted by Orchid Whisperer

Ray, that just happened to be the first description of permanent vs temporary hardness I came across at zero-dark-thirty in the morning while getting ready for my morning commute.

The concept is well known. So-called "temporary hardness" is associated with precipitation and scale formation, which can be induced by boiling, the remaining water will have lower hardness. It is associated with Ca and Mg bicarbonate (the Wikipedia page on hard water describes the chemistry in general terms, and also describes the difference from permanent hardness). My point is the OP was correct in saying some hardness can be removed by boiling; it depends on what minerals are dissolved that contribute to the hardness.

The problem with that is that in order for the dissolved solids to precipitate - the scale to deposit, if you will - the water must evaporate, which concentrates the solute, not dilutes it.

Maybe, based upon my experience, I'm just missing something, or maybe it's just a "terminology in the subject area" that's different.

[OrchideeNormus]

This is interesting to see this debate because the information I've been finding regarding this subject can be contradicting. Just like this conversation lol.
I suppose the important part for me to understand is that my water is definitely not good for orchids. Any other house plant or cacti I have has never had an issue, but I noticed a salt build up right away on the roots when I got my first orchid. After my initial research I did try boiling the water and allowing it to sit for 24 hours before using it, I even tried adding the water treatment for my fish tank to it lol. Now that I've got this TDS meter... I'm just trying to figure out what all that mean now lol. As far as complaining about the water company, as I mentioned before, it's been done before and failed. The people who run it have the monopoly on it somehow in this community and seem to have friends in high places. The ones who have already gone up against them have more pull than I do in this community. If they couldn't do anything about it, I highly doubt there's much I can do that will have a different outcome. I will see if I can't get that report today, they are already 20 minutes late so we shall see if they even show up today. For now the best I can do is be conscious of what I have learned and apply that knowledge to my life ♡

[estación seca]

Are you on the reservation?

[OrchideeNormus]

Originally Posted by estación seca

Are you on the reservation?

No I'm not

[Orchid Whisperer]

Yep, you're missing something.
(Still using the Chemcraft chemistry sets at Georgia Tech? )

The heat drives a bicarbonate / carbonate reaction.

This website provides a good explanation, authored by chemists: Water Hardness

[Ray]

Originally Posted by Orchid Whisperer

Yep, you're missing something.
(Still using the Chemcraft chemistry sets at Georgia Tech? )

The heat drives a bicarbonate / carbonate reaction.

This website provides a good explanation, authored by chemists: Water Hardness

Hah! It has only been about 50 years, so what the hell.... Besides, merely boiling temperatures rarely played a role in my education. Start talking in the 2000°C area, and I'm far more comfortable.

From reading horticultural info, I was under the impression that bicarbonates expressed alkalinity, and as that article states, it's the carbonates that constitute hardness.

That Washington U article was good. Thanks for digging it up.

---------- Post added at 03:41 PM ---------- Previous post was at 03:27 PM ----------

Originally Posted by OrchideeNormus

Are you saying flushing the pots isn't making any difference at all? I exclusively use RO water for watering and feeding. If flushing isn't going to make a difference I would rather not. It seems to be a popular habit and according to some deemed necessary. I have read several articles stating that the efflorescence won't hurt the plants so long as it's only on the medium and not on the roots. Only one of my phals is having issues with salt build up on the roots and I think I've figured that issue out (my ph was way too high for them to be absorbing anything). I was trying to be safe rather than sorry! If it's not necessary then tell me now and I won't waste my money anymore lol.

If you use RO for watering and feeding, then use your hard water for flushing, you're defeating the purpose of flushing, to some degree.

If you don't want to flush (I've not done a separate flushing in 20 years), consider following my approach:

• feed low-concentration fertilizer solution at every watering ("low concentration" will be defined by your watering frequency)
• always fill the pot rapidly to the top and let it drain, accomplishing feeding, watering, and flushing at once. If you still want to do a periodic plain water flush, use the RO.

Precipitates on the medium can, indeed, poison the plant. When they get wet, some of those solids redissolve, raising the solution concentration in the medium. The more extensive the buildup, the worse it is, and, if a newly-emerging root comes in contact with the mineral deposits, the tips will die and the roots stop growing.

Also, unless the pH was SO high that it resulted in the creation of odd dissolved radicals (which is unlikely), your plant can still absorb anything in solution. Read this.

[OrchideeNormus]

Originally Posted by Ray

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If you use RO for watering and feeding, then use your hard water for flushing, you're defeating the purpose of flushing, to some degree.

If you don't want to flush (I've not done a separate flushing in 20 years), consider following my approach:

• feed low-concentration fertilizer solution at every watering ("low concentration" will be defined by your watering frequency)
• always fill the pot rapidly to the top and let it drain, accomplishing feeding, watering, and flushing at once. If you still want to do a periodic plain water flush, use the RO.

Precipitates on the medium can, indeed, poison the plant. When they get wet, some of those solids redissolve, raising the solution concentration in the medium. The more extensive the buildup, the worse it is, and, if a newly-emerging root comes in contact with the mineral deposits, the tips will die and the roots stop growing.

Also, unless the pH was SO high that it resulted in the creation of odd dissolved radicals (which is unlikely), your plant can still absorb anything in solution. Read this.

Ray, I have indeed read the link you sent me lol. It comes up on Google search!
I use RO for feeding and watering...I don't exactly see how using pure RO water to flush, leaving only trace elements behind would defeat the purpose vs tap water that would leave lots of elements lol.
I already use a very diluted solution of fertilizer because all but two of my plants are in self watering pots. I use jacks classic orchid mix (can't remember the numbers off the top of my head but it's easy to find and Im at work so, sorry lol) I cut the lowest recommendation (1/4 tsp per gallon) in half. I recently added some calmag to this last watering to see if I can't help jumpstart the ones I set back last year. I also adjusted the PH because when I checked the water I was using it was 9.something...I think at that level only 3 nutrients are being absorbed according to the information I've read on it recently. I can explain further later if you need me to, but for now it's back to this matted poodle lol. Thanks everyone for the information, it's been more than helpful.

[OrchideeNormus]

Originally Posted by Ray

If you use RO for watering and feeding, then use your hard water for flushing, you're defeating the purpose of flushing, to some degree.

[/URL]

I just realized that I misunderstood what you were saying here. I took this as, if I use RO to water then I should use tap water to flush otherwise it would defeat the purpose. Now that I'm going through this again I can see you actually mean the opposite lol. My bad, my dyslexia was showing 😂 Now Im less confused!

---------- Post added at 09:17 PM ---------- Previous post was at 08:31 PM ----------

Originally Posted by estación seca

Here in AZ with very mineralized water of high pH, there are several ways around these problems.

pH of 8.5-9 just doesn't work for most orchids. Not many nutrients will be absorbed. Testing with an aquarium pH kit for high pH, you can try adding a tablespoonful of regular white vinegar to a gallon of your water, checking the pH, then repeating until you have something around 7. From that point forward add that amount of vinegar to each gallon of tap water you use.

You didn't describe what kind of self-watering system you use. Some of them suck up water from below, then evaporate it from the surface. Others (Ray's semi-hydroponic system, for example) provide water from above, but still evaporate mostly from the top. The problem is mineral buildup on the medium surface. This can be minimized by not allowing the medium to go completely dry, or by watering from above, frequently. With Ray's S/H method one can water from above frequently - daily or more would not be a problem. Also, with Ray's system, one should completely fill the entire container at each watering, displacing all the air.

If the medium never dries completely, and you flush through from the top frequently, you will have much less trouble with salt buildup in media.

Most desert cacti, by the way, do better with high-mineral, high-pH water. They are much less susceptible to various fungi this way. Most house plants do not like high pH and high mineral content. This is why so many develop brown leaf tips - the water evaporates and salts concentrate there, killing the cells. The dead zone moves back towards the leaf stalk as the distal parts of the leaf die successively due to high salts in the water.

For a couple of months I've been using my 600-1200 ppm water with a spray system for my orchids for most waterings. I will hand water with R/O about once a month. It's been working OK so far.

As far as testing and controlling the PH, for my orchids I purchased a meter that you put in the water and it gives you a digital reading. I also have an aquarium so I also have a test kit for that, but it's not the kind with the strips. It's the chemistry set kind that comes with little flasks you mix the aquarium water and the chemicals they provide to test things like PH, ammonia, nitrogen, ect... While that's accurate and convenient for my aquarium, it's not quite so convenient for testing multiple orchid pots lol. I also purchased PH up and PH down meant for hydroponics to control the levels. (I don't add it directly to the pots, but adjust the PH to the gallon I mix for watering/ feeding)

I have two types of self watering pots. Some have the cone that goes down into the water and some have wicks that hang into the water. The LECA seems to react the same for both types of pots as far as how moist it stays, only the very top layer dries out but everything below stays moist. When I water, I do it from above and through the media. As of right now, the reservoirs are large enough that I really don't need to water more than every three weeks to a month. I know that will likely change when summer comes. Every few days I might also mist the top layer and any air roots with plain RO water. Looking at everyone right now and only two of the pots have a little bit of build up on a few pebbles. One is my encyclia adenocaula so I don't really think that's a surprise since it's one of my first orchids and I set it back a bit last year. And it should be in its dormancy right now (That is a whole different thread, it's really not acting the way I've read it should right now because it's also working on a new growth lol. Yes, I'm giving it water because it seems to be active) The other is my baptistonia echinata, again Im not surprised, it's also another I got early on and it's also suffered some set back due to my lack of knowledge early on. They both lost most of their roots when I repotted them originally into semi hydro. I shortly after found that the self watering pots were similar enough to the semi hydro system and much easier for me to maintain so I made the switch to that. Since then they have struggled but both now have new growths, the baptistonia actually is working on a second new growth and has new roots coming in. Anyways, the point is both of the pots I have buildup in have plants with a comprised root system. It would make sense that they aren't able to absorb all the nutrients therefore leaving some behind.

It sounds like you keep your plants differently than mine. Im happy to hear that you've found a way to use your water. I'm not sure I'm going to have that luxury unless I change my entire setup again.... which I've actually considered. There are just so many ways to keep orchids, I do love how easy the self watering setup I have now is... but I find myself asking if it's better for the orchids, or just me lol. I am really interested in keeping them mounted or in baskets, but the amount of water I would need ro sustain that setup is intimidating. Especially because I am scared to share water!

I already planned on taking advantage of monsoon season 😉 great tip, thanks!