Lava rock to hold LECA down.

[MateoinLosAngeles]

Anyone use lava rock on top of their S/H pots to hold the LECA down when watering?

I've been using small lava rock and small river rocks, however, I've started to see some roots avoiding the pot and I wonder if the small size of the lava rock might be blocking some air out of the pot.

I'm considering trying something else like maybe big river rocks, bigger than the LECA, just to make sure there's sufficient space for the roots to grow into and for the air exchange to run smoothly.

Any other alternatives?

[tmoney]

yeah, we use small grade granite type pebbles as a top dressing, specifically to stop the leca from floating up and out when flushing.

as a thin layer on top, we haven't noticed any significant negative effect. on some of the pots we just throw big river rocks on top to hold the leca in. either way, doesn't seem to matter much.

[Ray]

Try soaking the LECA longer before use, so it will be come saturated and sink.

[MateoinLosAngeles]

Originally Posted by Ray

Try soaking the LECA longer before use, so it will be come saturated and sink.

Yeah, I always do the 48h soak at a minimum and I’ve potted plants in LECA stored in RO water for several months. Eventually the upper top layer ends up with some beads floating when watering.

I have a Phal bellina thriving in S/H, it has a plastic disc to reduce evaporation rate and I water it every day flooding the pot, thirsty she is. Still get beads to float up to the surface. I have about 40-50% humidity day-long but I’ve noticed my reader marking lows of 30% which I’ve only seen at 4-5am in the rare occasions I had to wake up that early for work.

The only issue I have with the LECA floating out of the pot is both “erosion” (leaving deeper holes at top of pot) and having to handle the mess picking up the beads from the grow trays. I have a drainage system under the trays with a mesh top to prevent obstruction but if enough beads gather around it slows drainage drastically and risks overflowing the entire tray. I wanna make it easier for myself, especially because I grow indoors in an apartment so overflowing messes are less forgiving.

[Leafmite]

I tried LECA a few years ago but stopped using it as it would move around too much, disturbing the roots. Not sure if I was using the wrong type of LECA but the roots did not cling onto the LECA as they do with lava rock.

I have tried a few different mediums and I am going to stick with pure lava rock. I use the stuff sold for grilling (or landscaping) for most of my potted orchids. I just bought lava rock meant for bonsai culture (I have a bonsai tree) and am using it for the Zygos. If they like it, I will probably use it for any orchid that likes more moisture. The small rock wicks the water from the saucer and stays damp for a couple of days.

[tmoney]

well, even after soaking, while watering the leca always seems to come up and we lose a pebble or two, as meteo also experiences. probably part of it is that watering happens in the kitchen sink with these, and i run the tap hard and fast to fill the whole pot and then let it drain. the leca just comes up. like leafmite says, it has worries me that some plants would visibly rise up with the media when watering.

using even a very fine layer of the small decomposed granite completely stops this problem. its turned out to be a very nice solution to a problem. also, i was just watching a vid from mygreenpets where he was talking with stephen and dustin miller. miller pointed out that keeping a moist top layer also encourages the top/newly emerging roots on paphs to stay moist and encourage growth. makes sense and just another reason to use a top dressing with s/h!