I've been thinking for a long while now on what it might take to set up a full feedback watering system for container plants. Seems like it'd be wonderful for anyone who was going on vacation, or who was lazy, or who just wasn't that great at judging when to water

As I see it, there are three obvious necessities...

1) A way to accurately predict moisture levels in the medium
2) A program (or, I guess we could go strictly mechanical...) to interpret moisture level reading output and interface with...
3) A watering system capable of delivering a set amount of water to any one of many plants

Now, perhaps it's the 3:45 AM in me talking, but it doesn't really sound THAT difficult. Maybe there's already something like this available?? I don't feel like googling anything at the moment.

At some point... I'd like to try setting this up. A small project maybe even adding a few extra components so that pH is tested at certain intervals and then automatically corrected. I could certainly get a bit carried away with this

Of course, we don't want to take away all the "fun" of keeping plants... there will be an OFF switch for such occasions when you feel like you're not spending enough quality time.

Alright, that's enough. Time for bed.

~Derek

My potted plants, including citruses, gets watered twice a day during summer. As long as my potting media have very good drainage, I never had problems.

But I got carried away with my inground plants. I have statistically analyzed long term agromet data, reprogram timers to allow easy readjustments depending on biweekly seasonal adjustments, comparing actual and forecasted data side by side. Since the water holding capacity of my soil is great, the readjustments are easy to do, most of the time it averages out to long term data predictions of evapotranspiration demand on a biweekly basis, and so need to add a feedback system for me.

You may be on to something... well drained media could easily be set up on an open loop control system, since it can't really be very easily over-watered. It just sounds like so much fun to set up the closed-loop, actually monitoring soil levels and adjusting moisture, pH, nutrients, etc.

At any rate, I'll give it a bit more thought... big issue seems to be proper sensors *shrug*

~Derek

The moisture meter sensor is the most crucial and perhaps the only sensor you would need to fully automate. You can forget the complex evapotranspiration and energy balance modeling, but whenever the sensor says you're dry, then you water with the preset amount (as per water holding capacity plus a little bit more for drainage to wash away salts).

Derek, the "man free" computer smart watering system that you are talking about already exists in the commerical greenhouse industry - Millet

Well, I figured as much. Still, perhaps as a summer project (gotta do SOMETHING to keep me occupied until school starts again in the fall) I'll work at setting one up myself, just for fun

Oh, off topic, but I'm graduating Saturday the 29th (of this month) with my BS in Mechanical Engineering!! One more exam on the 25th and I'm all done; it all goes by so fast!

Anyway, if I ever get my little (already been done by someone else) project off the ground, I'll keep everyone posted on my progress.

~Derek

Derek, way to go - CONGRATULATIONS on your degree. Mechanical Engineering is a hard degree, lots of math. I "know" my son is a ME. Proud of you! Now go make the big bucks. - Millet

Derek, I'm a new member spending way too much time reading through these forum posts.

Your idea for a "manfree" watering system sounds like a great idea for vacations. Unfortunately, I'm definitely NOT ME material, and would never be able to put such a system into action.

However, if you ever work out a system, and would consider sharing your info, I'd be happy to see it. My son, age 12, is a budding engineer at heart, and is never happier than when he's puttering away at some new project combining math, technology, electricity, computers, etc. etc. So with a little "start up" guidance, he'd be able to help me out!

Good luck with the project, and congratulations on graduation!

I've added an automatic water system this year. Below is the key 'mechanism', a timer and a meter.



I put a splitter on a faucet and ran a short hose to the 'timer' ($20 on sale a Home Depot). Immediately after the timer, there is a meter ($20 on Ebay). Past the meter, there is about 200' of hose and PVC. The water exits the system at 'variable bubblers' sitting next to each tree. (bubblers, tubing and PVC cost $140)

It emits water for 45 minutes every other day (8 gal per tree). I watch the meter to be sure it is working.

The system waters 16 in ground fruit trees. My citrus get collected rain water which will require a pump station if I want to do automated watering with it.

Mark