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Soil testing in the garden

Is anyone using the Ryset ph and moisture meter? Bought one recently and I’m wondering how accurate it is. The results I get for soil testing differ quite a bit from the results with my old strip tester. And when I placed the meter in a glass of water, the result was “moist” - not “wet” which is what I expected!

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Welcome to the community.

I’m old school and use my finger to asses soil moisture level, but I need a meter to assess the ph in our hydroponics system.

I’m not sure about the moisture meter component, but if your meter is not calibrated it will give you the wrong ph readings.

Have you calibrated your meter? Have you got a bottle of ph7 buffer solution to do the calibration with?

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From one source it appears in order of decreasing reliability/accuracy for soil testing. It
Laboratory test
Litmus/paper strip Test kits
Liquid colour/dye test kits.
In ground residential probes.

It would seem reasonable that repeatability depends on calibration and consistent methods.

Noting @meltam
Ryset list on their web site a calibration solution kit.

My Searles “Quick and Easy to Use” soil pH tester came with these not so quick and easy to use instructions. Draw your own conclusions.

P.S.
My needs may be a little different.
I only need the red side of the scale around the 5 mark, our norm. I don’t think it adds value.

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Possibly not that accurate.

Accurate soil moisture probes include things like tensiometers and neutron probes. These need to be calibrated to the soil (soil samples taken and correlated to the probe reading).

There are others like gypsum blocks, but these need soil moisture correlation as well.

A stick in the ground type probes won’t be accurate as they aren’t calibrated/correlated to a particular soil. They may only at best give an indication of whether moisture exists or not…and whether a pot/plant may need watering. Whether this moisture is available to the plants is another matter. Overwatering is usually not an issue for most plants when gauges prove not to be reliable.

Being cheap, they may be more of a novelty rather than a scientific piece of kit.

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Having also had anomalous results from such devices I have little faith in them. Without getting too complex accurate pH probes are glass electrodes which are expensive and delicate. Metal electrodes are cheaper and tougher but not accurate. My main concern is they tend to be erratic, giving results that vary for no apparent reason.

Single probe type are the worst because they rely on an electrochemical effect that is dependent on moisture and pH. I don’t know how you untangle the two under those circumstances.

Is this the model you have? I may have more to say if it is.

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Thank you for your reply. I didn’t know the meter had to be calibrated! I’ll try to do it.

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Thank you for your reply syncretic. Yes, that is the model I have, and I’d be interested to hear what you have to say about it.

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Thank you phb. A frustrating business for something that should be simple!

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Thank you for your detailed reply. There’s obviously more to this business of soil testing!

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I cannot give you an authoritative answer re the Ryset twin probe as it would need to be tested in the field and the results compared to a proper laboratory analysis - and that I cannot find. This vendor like most others does not give any information about how it works nor any data on its accuracy and precision. Whether anybody has done any such test is hard to say. There are two problems here.

  1. Look at the Ryset version here. Now compare it to this one labelled “Sonkir” and this one that is a no-name. They are all basically the same thing, the Sonkir says it also has a light meter and the no-name is confused about whether it does or not. I cannot determine who actually makes it so finding a matching review or the maker’s website are both hard.
  2. Laboratory tests are expensive and require careful procedure so it will take some resources to do a proper comparison of several dozens models and very few want to do that. Consider this review. It concludes that the Sonkir is great. It says double needle tech is “premium”. I agree on theoretical grounds it is better than one but that is only because single probe is terrible. That mob do not describe how they test and having said accuracy is important do not test accuracy! This mob also claim the Sonkir is accurate and reliable but give no clue how they know this.

It looks to me that the web reviews of this class of gear is like web recipes, you see the same thing over and over because they all copy from each other and don’t acknowledge it. If anyone can find a solid review that actually does measurements please say where.

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