Terrarium growing experiments - Page 9 - Orchid Board

Metallising · #81 12-23-2020, 08:53 AM

You are right, those are significant differences between fans of the same size. Mine runs 0.14A.

Draikan, I was reading again your post about:

Quote:

A wifi module for sending data to the web for logging
A speed controlled fan
An air temperature and humidity sensor
A mister to bump humidity up if it gets too low.

I have a few question if you don't mind

Could you give some clues on how to choose and set an wifi module for sending data to the web for logging? The free version of Adafruit only stores 30 days of data, do you know some other alternatives that store data longer?

How are you controlling fan speed?

If I got it right, you are using the misting system only to provide short burst of fine mist to keep humidity high but not for watering. The reason for that is because you don't have drainage on your tank and don't want to have water pooling, or is there some other reason?

Draikan · #82 12-23-2020, 11:24 PM

What is the flowrate of the fans you guys are talking about? Power is confusing because for the same power, different diameters will give different flowrates. The fan I've been using is only 2.4W, but it's 100CFM because it's 140mm diameter.

Quote:

I have a few question if you don't mind

Could you give some clues on how to choose and set an wifi module for sending data to the web for logging? The free version of Adafruit only stores 30 days of data, do you know some other alternatives that store data longer?

How are you controlling fan speed?

If I got it right, you are using the misting system only to provide short burst of fine mist to keep humidity high but not for watering. The reason for that is because you don't have drainage on your tank and don't want to have water pooling, or is there some other reason?

I did look at other datalogging/IOT services. Thingspeak was the other top contender, and I did use it for a while. I thought their interface and dashboard was ugly and not very easy to customize. The one month limitation from AdafruitIO was not a big deal for me, a month is plenty of time for me to catch any issues and test them out. I'm more interested in live data than a permanent record of conditions. Eventually it might be nice to see seasonal variations or compare years, but my techniques are nowhere near consistent enough for that to be useful yet.

Adafruit also had pretty good libraries, and an arduino variant with the wifi module built in. I didn't want to have to mess with that part.

Fan speed is controlled with a PWM output from the microcontroller on the Metro M4 Airlift Lite: Adafruit Metro M4 Express AirLift (WiFi) - Lite ID: 4000 - $34.95 : Adafruit Industries, Unique & fun DIY electronics and kits
If you're trying to recreate it, I used the zerotimer library. I can share the code if anyone really wants it.

Regarding misting/humidity/drain etc:

Tank 0 (the original big orchid tank) has no drain, because I'm a dummy and I didn't think it would be important. I use a mistking w/ 10 nozzles for watering, but I can't soak and flush everything because the tray would fill up with water (and spill). This is the tank that inspired me to work on humidity control and build the second big terrarium.

Tank 1 (the little test tank that I used to develop the humidity control) has no drain because it was lent to me by a friend and I didn't want to drill it. I just water by hand, dunking each orchid in a cup. There is a mister on this tank, and it is controlled by the humidity sensor, but it does not "water" the plants. My goal was to raise the humidity by a very small amount when the sensor says it's getting too dry, without getting the plants wet at all. I don't want this mister to get the plants wet at all. This mister is fulfilling a similar function to just running an ultrasonic humidifier for a moment, but the equipment is cheaper, and easier to hook up to the existing RO water system. A humidifier could do the same thing, but I'd have to fill the tank, it would be more expensive, and the Arduino would need to control a 110V outlet. The solenoid mist valve is low voltage, easy to control, and cheap.

The second big tank (I guess this should be tank 2, I need to update the names of the data getting pushed to AdafruitIO) is meant to combine all the stuff I've been working on, and eventually replace tank 0. That includes a drain, automated watering with mistking to fully soak and flush mounts, fan speed control for constant low speed airflow and gusts of stronger wind, and a controlled minimum humidity so plants can't be stressed between soakings if it happens to be hot or dry or something else in my apartment air changes. I'm working on this tank right now. I've transferred the tank 1 fan and humidity control equipment over. I'm currently setting up the automatic watering and drain. I want to get the automation dialled in on this tank before building more.

Draikan · #83 12-23-2020, 11:24 PM

I guess maybe I should clarify further. The two misting systems do separate things.

This first one is pretty conventional. It's a mistking with enough nozzles to hit all the mounted plants on the walls. It's controlled by a mistking timer, and sprays a very dilute fertilizer solution. It currently runs for 3 minutes on Wednesday, Friday, and Sunday. Once I have a drain, I think this will run on the same days, but I want to run for 3 minutes on, wait 3 minutes, then run for 3 minutes again to make extra sure that everything in the mounts has had a chance to soak and dissolve before getting flushed out. I don't want to risk any of the mounts getting not quite soaked and accumulating anything.

The second misting system has a single nozzle. The controller reads the humidity sensor, and if the reading is too low the controller briefly pulses the solenoid valve to produce just enough mist to bump the humidity up a few percent. The controller doesn't do anything if the humidity is already high. This mister will eventually be fed from my RO tank, but right now I'm just using a spare pump to fill the tank with tap water. Our tap water is soft (30ppm TDS) and I'm not all set up yet.

A standard few days should be like this:
1) Mistking completely soaks plants, excess water goes down the drain.
2) Circulation fan is always running, some external air gets mixed in passively. This slowly drops the humidity toward the ambient humidity in the room. Ambient humidity, usually 60-70% for me if heater is off, is too low for many of these plants.
3) Most liquid water has evaporated from the mounts, humidity is dropping and the tank is getting too dry. I can't predict exactly when this will happen because it depends on time of year, home humidity and temperature, how many mounts are in the tank, etc. If I soak too soon I get algae, rot, etc. Too late and I get burned roots, crispy mounts, dropped buds.
4) Instead of soaking everything, the humidity control kicks in and holds the humidity at a level the plants like, without actually getting them wet. Humidity is still high, so there should be no harm to plants, but there is no liquid water available, so no rot or algae. The fan can keep providing lots of airflow because it's very humid air. The mister give a little burst each time the humidity gets too low.
5) It's time to soak again. The plants never got too dry, but they did get a break from being "wet" (with liquid water).

I made a terrible chart to help explain. Blue is the minimum humidity. Green is what I want. Red is what would happen without the humidity control.

The little test tank (tank 1) has been doing this cycle for months, just with me dipping plants to soak instead of using a mistking and drain.

The big orchid tank (tank 0) has been doing something more like the green + red cycle, but with the fan only running 30% of the time to minimize the drying. Which has the unfortunate side effect of not giving the plants enough circulation.

Draikan · #84 12-30-2020, 12:15 AM

I've replaced the tiny test tank (tank 1) with the second big orchid tank (tank 2) which I had built previously, but never had a chance to setup!

The dashboard link is updated for the new tank:
IO - Adafruit

Tank 2 is using the same humidity controller, fan, and sensor as the little tank, just with the settings adjusted slightly to account for the larger air space.

The fan speed is turned up slightly. The humidifying mister is allowed to run more frequently, now as much as 1 second each minute if the humidity requires it. The humidifying mister is using a single mistking fitting at the top of the tank pointed straight down. It currently uses tap water, but I intend to switch it to RO eventually.

The regular misting system currently uses two nozzles. This will completely soak the plants on Wednesday, Friday, and Sunday. This mister is on the same system as tank 0, so it's run by a mistking pump and draws from the same water reservoir as tank 0. The reservoir has a roughly 40ppm Nitrogen solution of k-lite.

Tank 2 has a drain (finally) so I can mist as much as I need to soak everything, and the extra water will just run out of the tank.

The drain is just a bulkhead to a clear 1/2" hose, into a 5g bucket, which I will need to dump every couple weeks.

This is the system I've been wanting to grow in for months. I'm really optimistic that this can provide excellent growing conditions for the plants I'm most interested in with minimal daily care on my part.

My immediate next focus will be to transfer plants over from tank 0 to tank 2, since tank 2 should have closer to optimal conditions. I want to divide some of the bigger plants, so I have divisions to trade and share. I'll probably let them spend a few months in the new tank first to make sure conditions are appropriate.

I missed the bloom on P. eumecocaulon, but it is working on a few more.

M. nidifica is still working on all its blooms, I think they could open any day.

And D. aberrans is in bloom too!

S. hirtzii is still working on its spikes.

And the puppy keeps growing.

I also want to start supplementing kelp max and quantum total once a month each, alternating every two weeks.

My plan for now is to:

Transfer plants to tank 2
Start using kelp max and quantum total
Upgrade external plumbing with RO filter
Divide plants

Draikan · #85 01-06-2021, 11:50 PM

Two plants are right in the middle of big blooms today!

T. andreetae is still going. I'm not sure if it's just mid bloom or if it's going to constantly be in bloom.

Almost all the buds on M. nidifica have opened at once. The flowers are prettier than I expected, the cream with red stripes looks great.

Roberta · #86 01-07-2021, 12:19 AM

Wonderful flush bloom on both!

Draikan · #87 01-27-2021, 02:15 AM

There's nothing big going on right now so this is just an update.

All the orchids were moved over to the new tank a few weeks ago. They all seem to be doing well. No real issues and the growth continues.

I also transferred the mistking over to the big tank, so the daily watering is automated again. I'm still adjusting the nozzles slightly, but the coverage is almost able to soak everything. I'm doing 2 minutes to wet everything, wait 10 minutes to soak/dissolve, then 2 more minutes to flush. Any extra water goes right down the drain and doesn't keep the tank wet. The circulation is enough to dry off all the leaves and pull the humidity down below 90% by lights out. Watering is now on Tuesday, Thursday, and Saturday. I do the weekly maintenance and manual watering on Saturday.

I soaked them all with kelpmax for the first time last weekend. Next weekend they'll get sprayed with Quantum Total. After that they'll be getting either Kelpmax or Quantum Total on every other weekend, when I water manually.

P. niveoglobula is working on 3 keikis, they're hard to see:

L. bohnkiana is blooming for the first time in the two years I've had it. I don't think this is because the new tank is a better environment, I think it's a stress reaction to being moved. "I might be dying, better reproduce":

The Stelis species "mini" divisions are doing much better in the new conditions, with tons of new foliage and the healthiest roots I've ever been able to grow:

I think this is what orchid roots are "supposed" to look like?

At this point many of the mounts are >2.5years old, and they pretty clearly need fresh media. I just don't want to mess with them because the plants are actually doing great! S. hirtzii is probably the best example, healthy foliage and constant growth, but the sphagnum is nearly mush and the roots are probably suffering:

Not sure what I'll do next. I should be working on the next versions of the sensor and controller, but plants and plumbing upgrades feel more fun at the moment.

DirtyCoconuts · #88 01-27-2021, 08:38 AM

A pump sprayer, some patience and a pair of tweezers and you can spray most of the sphag off those roots.

Spray, let it get soaked and then massage the tweezers along the mush. Most of the goo will be removable.

Love these updates

Roberta · #89 01-27-2021, 10:43 AM

Especially for those "Andy" plants on cedar shingles (but applies to other mounts too), when I wonder about remounting, I cut the fishlines. If the roots are well attached, the plant stays in place, and I'll just pick off any excess sphag that I can. If it falls off, (which especially happens if there is sphag between the plant and the mount and the roots just grew into the sphag) then it's easy.

DirtyCoconuts · #90 01-27-2021, 11:44 AM

It’s good advice, Roberta.

I’ve become a snob about mounts and I find that commercial ones are often lacking In the exact ways you mentioned. Mediocre choice of mount and they put the sphag in the wrong place