question about a soil moisture meter

[budsofmadison]

i been using this soil moisture meter and im just wondering how long do you normaly leave it in the soil to get a reading ?
i have read 30 to 60 seconds and the manual says do not leave it in the soil for longer then 10 mins
i can check my soil and 60 seconds later it said for example 8 but if i leave it in the ground for a few mins it will go to 3 or 4

 

[Amnesia]

I use one that looks like that almost every day. I haven't noticed it changing much after it's in the soil. I don't leave it in for long, though.

 

[budsofmadison]

I use one that looks like that almost every day. I haven't noticed it changing much after it's in the soil. I don't leave it in for long, though.

try it an see and let me know i have often wondered if mine was fcked up

 

[Rootsruler]

I have the digital version but don't use it much unless I'm having plant issues. Mine works more or less like the Bluelab pH pen I have. Most people will stick the pH pen in the solution and assume the reading they get in the first few seconds is where it is but I leave it for a minute or two for it to settle in and give me the true reading. Same goes for my soil/pH probe. I leave it in for a minute or so before I take the reading as accurate but I don't really use it as a moisture meter. I use it more for soil pH.

 

[budsofmadison]

well how about this when you stick them in the soil and you know u gotta be going through some small roots rubbing up against bigger roots do u think the meter would pick up the moisture that the roots have ?

 

[budsofmadison]

here is what mine does over 6 mins in pictures timestamped

 

[Amnesia]

try it an see and let me know i have often wondered if mine was fcked up

Okay. I'll do that in a few hours when the light is on.

 

[Rootsruler]

here is what mine does over 6 mins in pictures timestamped
View attachment 12248View attachment 12249View attachment 12250View attachment 12251View attachment 12252View attachment 12253View attachment 12254

Operating normally. It's always best to let them settle in and give you the true reading. Because I use mine for soil pH readings it doesn't take as long to settle in but for moisture mine takes just as long. If I'm using it to check soil I usually stick it half way into the soil and go do something else for a few minutes to let it settle in and give me a true reading.

 

[budsofmadison]

Operating normally. It's always best to let them settle in and give you the true reading. Because I use mine for soil pH readings it doesn't take as long to settle in but for moisture mine takes just as long. If I'm using it to check soil I usually stick it half way into the soil and go do something else for a few minutes to let it settle in and give me a true reading.

i watered those plants 5 days ago each got 1 gallon and there was no runoff , according to that meter after it settled its time to water again but the pots still fell heavy when i pick them up
i can say that its only the bottom 2 or 3 inches that would be still read moist 4-6 but not soaked so if the the top 7 inches is in the dryer zone say 5 or below would that be ok enough to water without over watering or should u wait till the bottom 2 or 3 inches is in the dryer zone

 

[Rootsruler]

That's why I don't like using them as water meters. They're calibrated for other types of plants that don't like as much dryback as weed does. It'll tell you it's dry or time to water but weed likes soil that is damp at most.

Also our meters measure from the tip. If your tip hits a dry spot it'll say it's dry.

 

[budsofmadison]

That's why I don't like using them as water meters. They're calibrated for other types of plants that don't like as much dryback as weed does. It'll tell you it's dry or time to water but weed likes soil that is damp at most.

Also our meters measure from the tip. If your tip hits a dry spot it'll say it's dry.

funny when you say damp because i posted the question in the other world about is damp soil the same as wet soil

 

[budsofmadison]

That's why I don't like using them as water meters. They're calibrated for other types of plants that don't like as much dryback as weed does. It'll tell you it's dry or time to water but weed likes soil that is damp at most.

Also our meters measure from the tip. If your tip hits a dry spot it'll say it's dry.

so in your opinion its ok if the soil is damp when u water just as long as it is still not wet ?

 

[MysticEpipedon]

here is what mine does over 6 mins in pictures timestamped
View attachment 12248View attachment 12249View attachment 12250View attachment 12251View attachment 12252View attachment 12253View attachment 12254

I wonder if creating the hole, itself, helps dry soil right around the electrode, so conductivity drops and the reading changes.

 

[steamroller]

I use the meter you have to double check things.
On my 5g buckets I have holes drilled on the side of the bucket at 1/4, 1/2, 3/4 .
I check them all if I am uncomfortable with my decision to water or not.
I never leave it in for longer than it takes to read, but do move it all over to get a consensus.
I would not give mine up even if I don't use it all the time.

 

[budsofmadison]

I use the meter you have to double check things.
On my 5g buckets I have holes drilled on the side of the bucket at 1/4, 1/2, 3/4 .
I check them all if I am uncomfortable with my decision to water or not.
I never leave it in for longer than it takes to read, but do move it all over to get a consensus.
I would not give mine up even if I don't use it all the time.

have the same a whole about 2 inches from the bottom then half way up check my pics and the time stamp if u leave it in the reading changes so how do u know which is correct 30 seconds after u stick it in or if u wait 5 mins and the reading is different then what it was at 30 seconds

 

[budsofmadison]

I wonder if creating the hole, itself, helps dry soil right around the electrode, so conductivity drops and the reading changes.

well the whole would still have the probe in it so no air would be getting to it until u removed the probe , then i can see the whole drying a lil

 

[Amnesia]

I use mine to help me know when to water, but it's not the only thing I do. Mostly, I look at the plants. They'll let us know when they want water. I also check the humidity in the tent. The age of the plant seems to matter, too. So, I consider all those. Eventually, I learned that when my meter reads about '2' near the bottom of the pot, the plants need water.

The light is on now, so I'll do the 5-minute check. I was distracted by trying to do time-lapse video with my phone.

 

[Aqua Man]

You should place the meter into the saturation zone… bottom 2-3 inches.

This will explain a bit about the hows, whys etc.

Watering cannabis explained by Aqua Man

This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm not presenting my opinions as facts so take from this what you like. I will be putting it in subsection format for easy reference. First I want to make an...

budbuilders.org

 

[steamroller]

have the same a whole about 2 inches from the bottom then half way up check my pics and the time stamp if u leave it in the reading changes so how do u know which is correct 30 seconds after u stick it in or if u wait 5 mins and the reading is different then what it was at 30 seconds

I do instant readings.
Probe stays in no longer than 15 seconds.
Why add to the confusion?
It only guides me when unsure.
Listen to your plants also.

 

[Amnesia]

The light is on now, so I'll do the 5-minute check.

I forgot that the plants needed water today. I did the test anyway. The meter reading went to '2' and stayed there for the whole 5 minutes.

It occurred to me while I was watering that a possible explanation for why a meter would start high and then drop would be that the soil is moist up high and dry down low. If that's the case, even if unlikely, then the meter might do what it's doing. I'm thinking soil that's compacted or not very porous could cause it. I'm also guessing that not watering till there's runoff might cause it, too, especially if checking right after watering.

 

[Aqua Man]

I forgot that the plants needed water today. I did the test anyway. The meter reading went to '2' and stayed there for the whole 5 minutes.

It occurred to me while I was watering that a possible explanation for why a meter would start high and then drop would be that the soil is moist up high and dry down low. If that's the case, even if unlikely, then the meter might do what it's doing. I'm thinking soil that's compacted or not very porous could cause it. I'm also guessing that not watering till there's runoff might cause it, too, especially if checking right after watering.

Or not watering thoroughly enough

 

[Rootsruler]

Or not watering thoroughly enough

One of the reasons I like bottom watering is I know the entire media was saturated. Top watering can create water columns if you're watering too fast. If you stick your probe in and you hit a dry spot it'll tell you it's dry regardless of how wet the surrounding media is.

 

[Aqua Man]

One of the reasons I like bottom watering is I know the entire media was saturated. Top watering can create water columns if you're watering too fast. If you stick your probe in and you hit a dry spot it'll tell you it's dry regardless of how wet the surrounding media is.

Imo understanding watering practices and media is important. I personally don’t like bottom watering for a few reasons but as always if something is working then no need to do it differently

 

[Rootsruler]

I think a good way to do it if you aren't screening your plants is to go ahead and top water normally but every few weeks give them a good bottom watering to make sure all the media gets moisture.

 

[Aqua Man]

I think a good way to do it if you aren't screening your plants is to go ahead and top water normally but every few weeks give them a good bottom watering to make sure all the media gets moisture.

Yeah not a bad practice especially if your having some challenges with it

 

[Amnesia]

How about doing a postmortem on soil? By that I mean looking at the soil and the roots to see how well they grew. That could provide some feedback about how well a soil mix works.

 

[MysticEpipedon]

Imo understanding watering practices and media is important. I personally don’t like bottom watering for a few reasons but as always if something is working then no need to do it differently

Bottom watering is OK, provided you bottom water just enough or less than is needed to get the medium completely wet. That's not always an easy estimation.

I should probably run an experiment on how long the bottom of a pot has to be saturated before reducing conditions take over in the saturated zone. I would guess a couple of days.

 

[MysticEpipedon]

How about doing a postmortem on soil? By that I mean looking at the soil and the roots to see how well they grew. That could provide some feedback about how well a soil mix works.

I do that all the time after a grow. I've found dry, rootless zones in cloth pots and sometimes voids with no soil along the side walls of a hard-sided pot.

I've found that the dry zones in cloth pots, in my situation, was because I didn't mix the soil constituents thoroughly enough. Typically the mix in the dry pockets had more peat moss than other parts.

 

[Amnesia]

I've found that the dry zones in cloth pots, in my situation, was because I didn't mix the soil constituents thoroughly enough. Typically the mix in the dry pockets had more peat moss than other parts.

I've found dry spots, too, and the soil mix was to blame. I read a recommendation somewhere to make sure the soil mix is moist before planting. So, I have been watering my soil while it's still in the mixing tub.

 

[Shaded]

When the top soil is dry as dust, my plants would get watered that day. At worst the next day.

I bottom & top water my plants. About half of the capacity of water goes into the bottom tray which gets sucked up in under a minute, and the other half gets poured into the top. After using the same pot sizes and same grow space you will eventually get into a routine.

Moisture meters are great for new growers or for people trying new pots/new mediums but I would not rely on them after that.

 

[freezeland]

I have found vpd a good indicator of when the plants are getting thirsty. It will rise. Leaf temps will also increase as the need approaches.