How to keep Leca from drying out. - Orchid Board

DMFLEIG · #1 08-08-2019, 03:59 PM

Hi!
I'm new to semi-hydroponics and my question is how to keep the Leca from drying out on top?
It looks like the top inch or so is totally dry but the reservoir is full of water.
I soaked the Leca for 36 hrs before putting it in a quart size plastic container with 2 holes up 1" from the bottom.
Everything looks good for 2 days and now the top is dry.
My hydrometer is showing 60% humidity.
What else can I do?

Ray · #2 08-08-2019, 06:31 PM

The wicking rate of the LECA is a fixed entity, but the evaporation rate from the top is not. That is controlled by the humidity, air movement, temperature and light levels.

If the plant is putting new roots out, you might water it or mist the LECA more frequently until they penetrate the surface. After that, don't worry about it.

Alternately, you might consider a disk of clear plastic (semi-rigid, like a sheet protector from the stationery store). Cut the diameter to be 1" smaller than the pot diameter, then cut a hole in the middle to fit around the plant, with a slit to allow you to put it in place.

Evaporation will condense on that film and drip back into the pot.

DMFLEIG · #3 08-08-2019, 09:12 PM

Thanks, I’ll try that. The roots are not very big or even healthy looking but the plant seems to like being in water.

SouthPark · #4 08-10-2019, 09:19 AM

Could maybe try top layer being scoria rock maybe? While the lower layer kept as LECA.

I realise your system is semi-hydro. Another option could be ----- automated surface water spray with programmed digital timer (with battery backup). Every once in a while, a spray comes on for 'X' number of seconds. But naturally, if it's possible to accurately have timed sprays automatically, then there would be no need for a different watering method.

Ray · #5 08-10-2019, 09:57 AM

One of the nice things about S/H culture is that, due to the inability to overwater, it can be automated. When I will be away for more than a few days, I simply use a lawn sprinkler and timer to water everything daily at 4 a.m.

DMFLEIG · #6 08-10-2019, 12:39 PM

I would love to automate but this is just one plant and it’s indoors. A sprinkler would probably make quite a mess. Lol. I am going to try using a shorter container so the leca doesn’t have as far to wick and a loose cover like you suggested. Would a cotton wick be useful?

Ray · #7 08-10-2019, 04:54 PM

Quote:

Originally Posted by DMFLEIG

Would a cotton wick be useful?

The LECA pellets probably wick better than a cotton string.

SouthPark · #8 08-11-2019, 06:09 AM

Quote:

Originally Posted by DMFLEIG

I would love to automate but this is just one plant and it’s indoors. A sprinkler would probably make quite a mess. Lol.

A sprinkler timer....... not a sprinkler itself I think hehehe.

I'm still waiting for a device to arrive - from ebay. It's called "Automatic-Drip-Irrigation-Plant-Kit-Self-Watering-Can-Timer-System-Indoor-Garden".

If it actually works a bit, I'm planning to modify it ----- and one of the modifications could be to just make a mini spray system, that focuses water spray only on the surface layer of media, such as scoria rock media, LECA etc.

A micro-controller (basically mini-computer with battery back-up and real-time-clock) can be programmed to just spray the surface at whatever times of day we want...... and the amount of spray can be for as long or as short as we want ..... such as at 8 AM, spray for five seconds. The less number plants we have, the easier it gets. Something like that could be quite nice for a single-plant case.

That ebay system currently isn't designed to be really flexible with the watering schedule and watering duration ----- which is why it needs to be modified.