Tap water
 

Is it critical to use distilled or R/O water for semi hydro?

Would tap water work if it has been aerated for a day or two?

Aeration doesn't remove mineral salts.

Check with your municipal water district what the TDS is. Some growers will go farther to into the water analysis but you need to start with the total dissolved solids in your supply.

You can get an inexpensive TDS meter. It might not be accurate (the mfg should tell you how accurate) but it will provide an idea. Ideally, you should start with 0 ppm TDS prior to adding fertilizer and other plant supplements.

OR you can get distilled bottled water or install an RO system.

(BTW, my water is not ideal but apparently good enough)

I have a decent tester but it hasnt been wet in at least a year. I'll have to go get some test/calibrate solution and see if my probe still works. I have a Milwaulkee MW 802 PH/EC/TDS.

You want zero, but what is tolerable? What is yours if you dont mind?

My uncalibrated cheap TDS meter says 30(±?) for the cold tap. I do run it through a manual multi-stage filter for my tea and chids. The last city report had it in the range of <20 — 195.

Every now and then (once a year? couple of years?) the city will flush and we get brown water.

---------- Post added at 08:09 PM ---------- Previous post was at 07:22 PM ----------

One other caveat. Most of my S/H plants are Trader Joe's catts. A couple are not-too-special Oncs, a bulbo and a Den. In other words, they aren't that picky.

I'm not sure why you would aerate tap water (?)

I recommend checking out the Houston Orchid Society article on general water quality. https://www.google.com/url?sa=t&rct=...2,d.eWU‎ Ray, a member here, is a good resource for info on S/H and can probably advise on the quality of water needed.

I water my plants in a large half wine barrel that is there to collect rain water. When we do get rain. Otherwise, I fill it from the hose. However, I keep it constantly charcoal filtered and it seconds as a dog watering Bowl/system.
Our tap water here tastes like taking a drink out of the swimming pool after fifty kids have been in it all day.
I do have RO water, but don't use it for my orchids. They like the dog water and have for quite some years so I don't argue with that.
I use the same water for my S/H plants and they seem to thrive on it.

I haven't tested our tap water eexcept I know its pH is on the high side (around 8.5). All of my orchids seem to be just fine with it except the Phrags get brown leaf tips. This stops a soon as I start using rain water. So I do try and collect rain water for them.

Thanks for the responses. I going to try semi hydro with one of the two Acacallis seedlings that I ordered next to one in bark. Also In the spring I'm thinking of putting a cymbidium and a couple of phals in semi hydro to give it a whirl. I have a feeling I wont go back to bark.

And the reason I aerate my water is because Ive read in several threads and books on making compost tea that it removes the chlorine(I'm not certain that it does without testing). So I use that on my orchids and other house plants.

I briefly looked at a few R/O systems and they were not as expensive as I thought. A 36 GPD system caught my eye. Can anyone recommend a certain system? Or even ones to stay away from?

While one does tend to focus on water for S/H culture, water quality is more important in relation to the desires of the plant, not the culture method.

One caveat, though: because of the wicking, evaporation, and longevity of S/H media, mineral buildup can be accelerated.

Check out my info and reverse osmosis and my prices on systems.

Thank you. R/O drinking water would be great to! Might start treating myself as well as my plants if I go semi hydro lol. I'm super pumped to get it going. Its been on my mind almost as much as baseball this week.

I'll start referring 'to Rays page before I ask questions that have been answered already. Thanks everyone for your patience, experience, and links.

Actually, RO drinking water tastes terrible! It rapidly absorbs carbon dioxide from their air, forming a weak carbonic acid solution with a pH of about 5.3, which tastes sour.

Most folks buying my systems for residential driniking and cooking add a "pH stabilizer" (calcite) inline cartridge to the delivery line.

Burz, if you don't have a ton of orchids, an RO countertop system is really convienent. All my orchids (27) are in S/H, and Ray recently created a portable countertop system that I hook up to my kitchen sink. I kept the plastic gallon jugs that had RO water I'd bought from a drug store, and I store my now 'home made' RO water in them. It's so much better than buying jug after jug of water and hasving to lug it all upstairs every week. !

---------- Post added at 07:53 PM ---------- Previous post was at 07:51 PM ----------

Hmm. I find no taste what so ever in RO water. It has no flavor. ??

How long does it take you to fill your jugs?

That's going to depend upon your water pressure and temperature.

The membranes used in the counter-top systems are rated at 50 gallons per day @ 20 psi and 77°F. If your at-the-tap water pressure is higher, it is likely to be higher at the membrane, too, even though the tubing will reduce it some, but colder water reduces the flow.

50 gpd is about 1/2 cup per minute.

I also bought Ray's countertop RO system. It takes me about 10 minutes to fill up a one gallon jug. I have definitely seen an improvement over the past two months using the RO water.

Burz, it takes about 12 minutes to fill the gallon jugs, but my case is, I am fairly sure, this is really unusual. My guess is that for 'normal' water systems, it's WAY faster. Here Vt , I have 2 gravity fed well houses up in the woods, and NO booster pump for the house, so, the water pressure is Soooo slight. I've been here in my house for 30 years, and am quite used to it, but others might not accept this situation. Anyway, with the booster pump, that most folks may not need, it's sooo much faster. Get this. Before I got the pump, it took 18 HOURS to make ONE gallon of water!! It literally dripped out of the tube, into the jug! Ray was really surprised, and of course, helped me out the choice of booster pump. He's been invaluable in my learning about all this. Don't know where I'd be without him :)