DaveW wrote: ↑Tue Sep 20, 2022 9:25 am
The problem with most watering devices I have come across is they don't work too well with small pots since the soil is not deep enough. Also, with gritty dry type cactus and succulent soils not in intimate contact with the length of the probe.
With sensors permanently in a pot you would need one for every pot, or at least one in all similar pot size as different sized pots dry at different rates. However, I have only used the ones that depend on galvanic action. Also keep jabbing the sensor into a pot could damage the roots.
Anyway, will be interested to hear your results as I have not seen that type before? Have you tried it with a transparent container filled with your normal potting soil to visibly see through the sides if the soil is dry when the sensor says it is? Say using the bottom cut off a clear plastic water bottle or similar as a pot with a drainage hole drilled through the base?
Hi Dave,
I’ve been testing this device now for maybe 3 months or so and was so impressed, I bought the company! Just joking - you have to be of a certain age to appreciate that one!
Seriously, I found it accurate enough to warrant me buying another five. At the time of writing, in the UK they are £4.79 for one, £11.29 for three (£3.80 each), or £13.99 for five (£2.80 each).
The battery, a CR2032, is a very tight fit. It’s not included, so these need to be purchased separately. Polarity is negative to the circuit board and positive to the metal holder. I haven’t tried it, but I would imagine a thinner CR2025 would work just as well because of the spring-loaded battery holder. But, a thinner battery would probably not last as long. In fact, I have some other types. Let me just check…
… Yes, I can confirm the thinner CR2025 and the very thin CR2016 also fit just fine. But, as above these would presumably not last as long as the thicker CR2032. I have no idea as to the battery life, but for future reference I will report back when one of my devices fails due to battery depletion.
They are designed to be permanently inserted in the soil, living alongside your plant and alerting you to your plant being dry, rather than you having to periodically remember to insert a pronged resistive-device into the soil to check how dry it is.
I see no reason why it would not work just as well in a small pot vs a large pot. Basically, when you know your plant needs to be watered, you press the small button to teach it the dry point. This only needs to be done once, unless you want to re-program it to a different dry point. The electrodes measure water content via capacitance as opposed to resistance and make no electrical contact with the soil. As long as it knows what ‘dry’ is, it should alert you to that threshold, whether it’s a small pot or a large pot.
Its total length is 14cm. The visible length will be less than that depending on how deep you insert the device, but normally you would only see 7cm of that length. It will be less conspicuous in a larger pot, but if being alerted to your plant being dry is more important to you than aesthetics, then this gadget should suffice.
When my devices chirp (soil is dry), I have stuck my finger a few centimeters into the soil to confirm the accuracy. To me, they do seem accurate and I have no reason to think otherwise. I don’t think it’s really necessary use a transparent container ‘to visibly see through the sides if the soil is dry when the sensor says it is’.
However, in the spirit of experimentation I have done just that! Furthermore, I have sown some seeds in said container… I now have a clear water bottle chopped in half with five holes in the bottom, filled with ‘cactus compost’, identification-unknown cactus seeds sown on the top and a capacitive hygrometer sitting in the soil... what could possibly go wrong?
If anyone does try one of these gadgets, one tip I would mention is to avoid moving or nocking the device once you have set it. If you subsequently knock the device, you might displace the position of the electrodes and alter the capacitance, therefore change when it alerts you.
-- Paul.