Hello! We'd love you to join in with our collaborative soil moisture testing experiment, to determine sensor response in a wide range of types of soil, and to ascertain the subjective points where soil becomes "too dry" or "wet enough".
Here's the place to discuss the experiment with us at Harvst HQ, and other home scientists...
Interested in this as I recently got a Watermate mini for my greenhouse with the moisture sensors and I’m still trying to get it dialled in.
In my limited experience of the sensors in multipurpose potting compost mixed with perlite ( seed trays and pots ), the readings are a good guide - 100 is saturated, dropping below 4 definitely needs water, 6/7 is a good level.
Only issue I’ve had is the timer schedule doesn’t seem to work when the moisture settings are set, and vice versa. I think I’ve worked out that they operate independently but if both are set they cancel each other out and the water doesn’t come on, is that correct?
What I’d like to do is have the system come on every day at 8am, but if the moisture level is above 8 it cancels the timed programme and doesn’t come on. On a really hot day if the moisture level happened to drop below 4, the system automatically comes on. But it would also still turn on via the timer at 8am the next day, as long as the moisture was below 8.
Reason being is I’ve got seed trays and pots in a 3-tier so they dry out at different rates, so just on a timed setting some get saturated, others dry out faster. Equally, just relying on moisture levels is tricky as some will be wet whilst others could do with water. Being able to run timed but also use the moisture sensors to prevent overwatering when some are too wet but also as a fail safe on a very hot day would be great if that’s possible? Should also help keep things in a more consistent range
Hi Gawain - the system should work as you describe with both timer and moisture settings, so I'll investigate and see if something's up. We'll send you a wireless sensor too, so you can run that in the system as well. Chris
Amazing, thanks Chris. Good to hear that it should work that way so if you’re able to help get my system fully running like that I’d be very grateful ( good dates to investigate would be 22-24 and 25-28 April as I was away much of that time and it didn’t come on, despite moisture levels dropping low. Seemed to work when I turned them off ).
A wireless sensor would be fantastic, I’ve got one that doesn’t quite reach as far as I’d like so wireless would be perfect. Thank you!
Hi Chris
Everything’s working really nicely following the latest update thank you; all the timer and moisture level settings are working as expected and feel like I’m starting to get it dialled in. Have to say I’m very impressed with the continual product development and ease of fine tuning the settings
Great stuff. I see some steps in your wireless sensor moisture reading. Are you comfortable with the reason behind these? Perhaps it's where it was moved. Disturbing the soil around the sensor will make a gap around the probe which will affect the reading ( drier, since there's more air around it ).
We're trying to ascertain whether any readings below 30% are usable. It may be that the 30 to 100 range is all that's needed. If 30%, when in compacted soil, is generally "too dry" for most plants, then we'll call that 0% moisture. Going further and reading dry air moisture isn't such a useful concept, for gardeners at least.
One of the steps was soaking it again the other day.
It’s a small fibre pot so dries out quite quickly. I’ll try a larger one after this, but this is what I’ve got so far.
Agree that 30% could be taken as zero
Small fibre pot
50g empty pot + sensor
76g full pot + sensor
Soil bone dry: initial reading = 9%
Saturated = 118g ( 8/5/22 ) 70% 42g water
Very dry = 82g ( 12/5/22 ) 36% 6g water
Extremely dry = 78g ( 13/05/22 ) 27% 2g water
Very wet and saturated, overwatered = 131g ( 13/05/22 ) 68% 55g water
Very wet = 121g ( 14/05/22 ) 60% 45g water
And I think the reason it’s not hitting 100% and there are some general steps is the whole sensor isn’t buried in the pot, there’s about 2” showing so won’t necessarily be working to full effect so I’ll repeat with a bigger pot
Chris, I can't find the soil moisture sensor for sale anywhere on the site. As you know, I've been asking for it for 11 months. Can you tell me how to buy it, please?
Here's the place to discuss the experiment with us at Harvst HQ, and other home scientists...
In my limited experience of the sensors in multipurpose potting compost mixed with perlite ( seed trays and pots ), the readings are a good guide - 100 is saturated, dropping below 4 definitely needs water, 6/7 is a good level.
Only issue I’ve had is the timer schedule doesn’t seem to work when the moisture settings are set, and vice versa. I think I’ve worked out that they operate independently but if both are set they cancel each other out and the water doesn’t come on, is that correct?
What I’d like to do is have the system come on every day at 8am, but if the moisture level is above 8 it cancels the timed programme and doesn’t come on. On a really hot day if the moisture level happened to drop below 4, the system automatically comes on. But it would also still turn on via the timer at 8am the next day, as long as the moisture was below 8.
Reason being is I’ve got seed trays and pots in a 3-tier so they dry out at different rates, so just on a timed setting some get saturated, others dry out faster. Equally, just relying on moisture levels is tricky as some will be wet whilst others could do with water. Being able to run timed but also use the moisture sensors to prevent overwatering when some are too wet but also as a fail safe on a very hot day would be great if that’s possible? Should also help keep things in a more consistent range
A wireless sensor would be fantastic, I’ve got one that doesn’t quite reach as far as I’d like so wireless would be perfect. Thank you!
link
Everything’s working really nicely following the latest update thank you; all the timer and moisture level settings are working as expected and feel like I’m starting to get it dialled in. Have to say I’m very impressed with the continual product development and ease of fine tuning the settings
We're trying to ascertain whether any readings below 30% are usable. It may be that the 30 to 100 range is all that's needed. If 30%, when in compacted soil, is generally "too dry" for most plants, then we'll call that 0% moisture. Going further and reading dry air moisture isn't such a useful concept, for gardeners at least.
It’s a small fibre pot so dries out quite quickly. I’ll try a larger one after this, but this is what I’ve got so far.
Agree that 30% could be taken as zero
Small fibre pot
50g empty pot + sensor
76g full pot + sensor
Soil bone dry: initial reading = 9%
Saturated = 118g ( 8/5/22 ) 70% 42g water
Very dry = 82g ( 12/5/22 ) 36% 6g water
Extremely dry = 78g ( 13/05/22 ) 27% 2g water
Very wet and saturated, overwatered = 131g ( 13/05/22 ) 68% 55g water
Very wet = 121g ( 14/05/22 ) 60% 45g water