Self-watering pots with leca

[Roberta]

A thought with regard to hard water (in semi-hydro or just general watering)... While fertilizers that are designed to be used with tap water have extra phosphorous (as phosphoric acid) to lower pH, with hard water with lots of calcium bicarbonate, that amount of acidity doesn't come even close to adjusting the pH of the fertilizer solution - it resolutely stays close to 8. I found that it took about a 1/2 tablespoon of vinegar per gallon to get the pH down to about 6.5. That bit of vinegar just puts the pH into the optimum range, and may also help prevent buildup of hard-water scale on the medium.

[orchidphile]

Hi, all.

There is one more thing I wanted to say about my method, and it's important. When you first put a plant into a self-watering system, you should soak the entire pot for at least half an hour, even if you don't use soaking after that. This ensures that the leca, the wick, and the gravel are very moist and gets your roots off to a good start.

I've actually had a lot less root loss and setback with this method than with the internal reservoir, although that method is still head-and-shoulders above the hassles of organic media, in my opinion.

---------- Post added at 05:51 PM ---------- Previous post was at 05:42 PM ----------

Roberta, My tap water's not that hard, but it does have over 200 ppm of "stuff" in it. I try not to use it at all for orchids, but if I run low on RO-type water, I sometimes use it for soaking only. For other houseplants I use tap water for soaking but not for fertilizing. So far, no problems. I agree with everything you said about harder water, and I think this could be a huge issue for people who fail with semi-hydro. With organic media, it gets more acidic as it breaks down. With an inert medium like leca, this doesn't happen. I think water quality is everything with this method and getting it right is worth the trouble.

[Ray]

Orchidphile - I think our disagreement is based upon what situation each of us is using in our consideration. I am basing my comments on having really good conditions for the technique, which is what I've had for decades in my greenhouse, and has continued in the high-humidity outdoor conditions in the summer since I moved.

If the LECA never dries, the degree of precipitation is minimized, if not prevented altogether, so very frequent watering of pots that are in an environment that allow the LECA to stay moist clear to the top, using a VERY dilute fertilizer solution keeps the medium very well flushed and aerated, while still supplying a sufficient mass of nutrients.

[orchidphile]

Yes, Ray, I think you're right. Unfortunately, I grow in a sun room that's open to my family room. I do what I can by standing pots in trays of water, running a room humidifier, etc, but I still get too much drying. The soaking and gravel top layer are my solutions to the problem, and they seem to help. Some day, maybe I'll have a humid greenhouse with an automatic watering system and all this will be moot.

[Roberta]

Originally Posted by orchidphile

With organic media, it gets more acidic as it breaks down.

With hard water like mine (TDS isn't really that bad, around 250 ppm, but it's mostly calcium bicarbonate) even the breakdown of bark isn't enough to give much acidity... I tested the water that washed through a potted Cattleya with really badly broken down bark and the pH got all the way down to 7.7 from starting point (out of the tap) of 7.9 . The buffering capacity of calcium bicarbonate needs lots of "persuasion" to overcome it... If yours isn't that bad, you're fortunate.

[SouthPark]

Originally Posted by orchidphile

Hi, Southpark. I've never posted pictures on here before, so I hope you can access these attachments.

Thanks orchidphile for uploading those photos. That arrangement looks pretty good.

Can those strips also be run up the sides of the pot? Up the sides, and then once the long strip gets to the surface (somewhere), then make have it lie horizontal a bit - along the surface (at the top of the pot). So - basically, put those strips through the holes at the bottom of the pot, then run it up the pot - maybe the sides of the pot.

[orchidphile]

Yes, Southpark, you can run the strips up the side and across the top. I think I mentioned that in one of the posts. The microfiber is super wicking, so it will do anything you want and pull the water anywhere you want it. The only thing I would worry about is maybe getting things too wet. Another thing I've tried, with plants like miltoniopsis, is to cut a few short lengths of microfiber and mix them in with the leca. In Europe, some people do the same thing with Synthic, but I can't find that in the U.S. I like using the pieces of microfiber better than pumice, which is very dusty and messy, a bit hard to find in my area, and more expensive.

[SouthPark]

Originally Posted by orchidphile

The only thing I would worry about is maybe getting things too wet.

Thanks orchidphile. Wet is ok for cases where the roots are sufficiently aerated. So decent sized holes in the pot and growing environment with good air-movement can help with this.

[orchidphile]

Originally Posted by SouthPark

Thanks orchidphile. Wet is ok for cases where the roots are sufficiently aerated. So decent sized holes in the pot and growing environment with good air-movement can help with this.

Yes, I guess you're right. I still have trouble getting past my old school thinking about what orchids need. It's amazing, isn't it? I'm sitting here looking at oncidiums, cattleyas, vandas, phals, etc., etc., all supposedly having different needs and all thriving in my self-watering system. They pretty much all thrived in regular semi-hydro too, except for the vandas. Lately, I've heard that people are growing cacti--not jungle cacti, desert cacti--in semihydro. I'm still trying to wrap my head around that.

[Ray]

If used with LECA, I'd never worry about it being too wet.

I tried an experiment in which I watered 300 plants (50% each Phalaenopsis Lemforde White Beauty and Oncidium Sharry Baby) every day for 6 months. Not only did I not lose a single one, they were significantly larger than a "control" set that get normal watering frequency.