Hi everybody :)
I'm new to this forum, so hopefully this is an ok thing to ask. I have a student project going on where we need to develop and pitch an idea for a product. As a plant lover, I obviously gravitate towards that subject so I looked at self watering pots and how they could be improved upon. I have an idea, but now I'm at the point where I want to gather user feedback. I think this might be a good place to get some input. If you have the time please let me know if you would be interested in a product like this and why/why not.

I think self watering pots are great in concept but they have obvious drawbacks:
- They are expensive
- They can't be used with in conjunction with pots you've previously bought
- If you want a bigger self watering pot you'll have to buy another one
- They don't do well with plants that need to dry out between waterings

A better solution would be:
- Something you can put in regular pots you use to make them self watering
- Something that registers the soil's dampness and reacts accordingly
- Something that can use different modes for plants that like to dry out between waterings or even stay moist

My idea is a self watering pot kit.
It contains of a water reservoir, a humidity sensor, a closing mechanism, a switch for different modes and a small solar panel with batteries and works as follows:
- The humidity sensor (which doesn't use any energy) senses when the soil goes dry
- It sends a signal to the mechanism to open once the soil goes dry according to the selected mode. It will slowly send out water to dampen the soil
- Once the soil reaches the desired dampness the watering mechanism closes
- The solar panel can collect energy for days/weeks at a time because plants usually don't need waterings every day
- If it's sunny and the plant needs more watering, the solar panel collects more energy which automatically allows it to open more often as required

Advantages:
- This will make it super easy to keep the plant's soil damp, since there is an actual humidity sensor and the watering mechanism won't just constantly send water
- You can use a whole array of different pot sizes instead of being stuck to the one you bought, making it cheaper in the long run
- The different modes can make this usable even for plants like cacti and succulents which don't like to constantly have wet roots.

What do you think about this idea? Love it? Hate it? Anything you noticed? I'd love to hear your thoughts, feel free to be honest. Negative feedback also helps!

Thank you guys for your time

What's the plan for dealing with the inevitable (based on the description provided) accumulation of dissolved solids in the grow medium?
Al

Sorry, I'm not a native speaker - can you specify what you mean by dissolved solids? If the soil isn't good anymore you can repot the plant like you would in any other pot. Please let me know if I misunderstood.

Maharkus, I think you got the meaning and your solution is the right one: If the soil goes bad, repot.

Interesting project. I will be interested to see your final design.

Thank you, Lucy :)
Do you have any experience with self watering pots and know of other issues you'd like to see addressed?

Tapwater contains carbonates of calcium and often magnesium as well as other dissolved solids (minerals) that affect both the pH and salinity of the soil solution. Watering copiously from the top so water flushes through the soil allows dissolution of the salts and mineral deposits which then exit the pot through the drain hole such that a stable pH and TDS level can be enjoyed for an indefinite period.

In closed systems, like you propose, all salts and dissolved minerals from tap-water and fertilizer/ fertilizer solutions remain in the grow medium to accumulate. This causes a rise in pH, making many nutrients unavailable for uptake; causes a high EC/TDS level, which makes water and nutrient uptake increasingly difficult as levels increase; and, contributes to skewing of the nutrient ratios in the soil solution which leads to antagonistic deficiencies and synergies that interfere with normal uptake of nutrients. Example: If someone is using a "bloom booster" type fertilizer with a high level of phosphorous, there is no way to flush the excess phosphorous from the grow medium. As the level of phosphorous builds, it limits uptake of calcium, potassium, copper, zinc, and especially iron; and, it synergistically increases the uptake of magnesium at the additional expense of calcium.
Al

Is it designed to be a closed system? It should have a way of cleaning and refilling the reservoir.

This is interesting:
https://www.gardeners.com/buy/...

Markus,
My take is this is best for medium to large plants (pots 12 inches and more) and in those cases could really help because those are hard to move for maintenance. And commercial applications so less frequent maintenance. I could see this tempting for commercial indoor landscape uses. Maybe outdoor too- I guess they also don't want to do frequent watering when they could fill a reservoir weekly or even less. With care, I'd suppose they could go a whole summer in decent condition on some restaurant's patio, then whole thing gets refreshed the following spring.

For a homeowner like me focused on small pots, the cost of the mechanics sounds like it is too $$ per pot.

(Bear in mind I have never used self watering pots)

If you could come up with an idea to water plants with fresh water from above when needed, that would drain through, that would be awesome. Would be a lot of pipes and faucets involved, but would make a great living space for a room of plants. (aka my happy place) Just dreaming.