Hi Jane,

Glad to hear that you have no problem with RO exclusively and it further makes me think that the problem stems from watering with RO exclusively in the absence of any fertilizer. I am fairly confident this is the problem that I observed. I have now switched to watering with RO water exclusively BUT supplemented with MSU and the problems I was seeing before are all disappearing.

Try watering a plant with nothing but RO (no fertilizers, no micronutrients, nothing) for 3 months, and compare to a plant that is watered with tap. You will see the tap watered plant perform much better, I can almost guarantee you. The RO water alone is just that - pure H2O. Even rain water has dissolved substances from the atmosphere. Pure H2O is incredibly good at dissolving things and it will dissolve the nutrients out of the roots in no time.

RO water with fertilizers is desirable and effective because instead of dealing with the random salts and minerals in tap/hard water, you are controlling precisely the amount and types of salts in the water.

One thing that may be helpful with clumping is to make a stock solution of your ferts. My MSU clumped as well and I actually threw away the first batch. Now, I make up a concentrated solution of MSU, from which I just add 2 tablespoons to each 1.5 litres of water...much easier!

mercury muffins, anyone? ;)

Before installing the water softener my well water was horribly hard. All my plants looked bad even my dirt house plants. Before I installed the RO I used rain water until the freeze and then bought distilled water. I got tired of that fast and decided to pay for an RO system.

In my office at work I use tap water on my orchids and dirt plants with no ill effects. Amazingly, even with a strong chlorine odor, the plants do not seem to be affected. The orchids are only brought in while blooming so its not a good measure of long-term effect. But, I have a 'lucky bamboo growing in that chlorine water and it is fine. No brown leaves and lots of growth. Been here for 3 years. Very strange indeed.

Calvin, your fertilizer method sounds like a good idea. Why didn't I ever think of that??

Jane

I hasten to add there is nothing wrong with RO water. Certainly a great starting point if you have it. In fact a plus if you are trying to grow some orchid species that require soft water such as Disa.

I have to report that after having a rainwater tank for over a year, i can discern no difference re tap and mostly rain water. But i only grow toughies.

A lot depends on the quality of your tap water. My ppm is usually around 300, quite acceptable to the vast majority of plants. I have a shady corner of rain forest plants, Pleuros, Dracs, Stelis etc. I water these with RO, add very little 20/10/20 with trace elements once a week. At least every 2 weeks I water them with tap water.

The reason for the tap water is that tap water contains a long list of trace elements ranging from Uranium to Cobalt6. Cyanide, Arsenic etc, etc are all present. Get a list of your local water board and you will be astonished what is in there in amounts so small that no harm comes to us. Fertilizer with trace minerals does not even come close to duplicating this. I have no idea if the plants actually need any of this but I suspect they do, anyway I see no ill effect of occasional tap water for sensitive plants (Disas excluded, they are a in a class of their own).

I used to water all of my plants with RO, including Cymbidiums, Catts, Oncs etc. Stopped that 5 years ago and see absolutely no difference.

Nick

:) add 2 tablespoons to each 1.5 litres
I thought that y'all use metric up there? :)

--Stitz--

My bad - how very unpatriotic of me. 30mls per 1.5 litres!!

Orchid growing has slowly converted me to talking in Fahrenheit and inches...it's tragic.

I hate the taste of my well water and buy bottled water for drinking on the run. My favorite is Pellegrino sparkling mineral water. If I have some left in a bottle I will pour it on my plants. Fizzes up like peroxide but I swear (totally nonscientific) the plants love it. So they do get a treat every now and then. It seems to green them right up!

Jane

Calvin, consider yourself fortunate to be able to converse in both measurement systems. I worked in metric and live in the English system. Now, I use both at home.

I never did grasp those dern Imperial gallons, though! :) Many forays into Canada however it seemed that different parts of the country handled the measurements differently during the "switch". I went into Alberta/BC, Ontario/Quebec and Nova Scotia.

--Stitz--

I built a 'greenhouse' in the basement of my late mother in Calgary and was amused at the PVC pipes sold at HD. 1/2", 3/4", 1 1/2" same as here but with oddball mm labels. A 2x4 in Canada is still a 2x4!

Nick

I think this thread needs to be resurrected.

I am coming from the aquatic plant side of things here so hopefully the majority of rules/best practices translate.

I have a pretty decent R/O-DI filtration system. It allows me to take my 280ppm TDS and 7.8-8.2 pH tap water to 0ppm TDS and a completely neutral pH of 7. It only makes sense that using this water to hydrate your plants would be silly, its completely devoid of any organic energy for the plant to feed from (granted they do have the organics in the substrate but lets not worry about those for this specific discussion). Human beings shouldn't ONLY drink pure R/O water for this same reason. This is why smart water/whatever bottled drinking water you like' has minerals/electrolytes added for taste, to satisfy this physical need.

So here's my question, would mixing pure R/O water with the recommended amount of say Dyna-gro foliage pro (1/4 tsp/g I think for maintenance) be any more beneficial than mixing it with my plain old tap water?

On a similar subject, i have watered indoor plants with the remaining liquid in my power aid 0/Gatorade/vitamin water 0 after its been warmed by siting in my car, never noticed anything positive or negative from doing this. I have also fed outdoor potted plants beer and (please dont think less of me, we all do it!) what our bodies turn the aforementioned beverages into when they leave our bodies, again nothing good or bad has come from any of it.

So I personally dont really think the plants care all that much what exactly it is that moistens their dirt but more so that it just isn't completely void of nutritional value or super loaded with them putting the balance of nutrients out of whack.

Obviously bsmith717 has never grown the cloud forest plants from central America and the Andes.

'So I personally dont really think the plants care all that much what exactly it is that moistens their dirt '

The other issue is that very few orchids grow in dirt. This forum is not about daisies but about orchids.

Nick

So your saying that an orchid with its roots in nothing but air could be grown only using pure R/O?

Of course not, MSU fertilizer is added to each watering. What I'm saying is that a group of orchids NEED clean water, don't thrive if tap water is used. Cymbidiums, Cattleyas encyclias etc do well with tap water. Masdevallia, Pleurothallid, Dracula, Lepanthes etc simply need either RO or DI water to reach their potential.

What do you think happens in nature during a prolonged rain? After debris, monkey poo and hummingbird pee is washed down, the roots remain soaked in pure rain water for the rest of the rain period. I have no problem watering with pure RO water which I do regularly once a week to wash out any salts which have remained with the roots.

Nick