Best moisture meters according to redditors
We found 90 Reddit comments discussing the best moisture meters. We ranked the 26 resulting products by number of redditors who mentioned them. Here are the top 20.
We found 90 Reddit comments discussing the best moisture meters. We ranked the 26 resulting products by number of redditors who mentioned them. Here are the top 20.
You can get a cheap/basic moisture meter for around $30 that should help take the guess work out of it.
HERE
a few key points:
Get a moisture meter and check for moisture. It doesn’t look like recent water damage. Tough to tell without a moisture reading.
something like this
A wood stove is my only source of heat so I have quite a bit of experience in this area. Here's some pointers.
Wear all the safety gear. Chaps, glasses, gloves, hearing protection. I cant stress this enough. I have seen the damage a saw can do to a shin. Not pretty.
Use a grease pencil and a stick cut to length to mark your logs before cutting. If all the pieces are the same size they stack MUCH nicer than if they are random lengths.
Sharpen your chainsaw before you use it. This is the best sharpener I have ever used Every time. Also sharpen it if the tip hits the dirt (keep the tip out of the dirt). A log jack will do wonders for your chain. The chain will stay sharper (again keeping it out of the dirt) and it keeps the end of the log up in the air and will prevent the chain/bar from binding.
Get a moisture meter like [THIS]
(https://smile.amazon.com/General-Tools-MMD4E-Moisture-Digital/dp/B00275F5O2/ref=sr_1_1_sspa?ie=UTF8&qid=1518026049&sr=8-1-spons&keywords=moisture+meter&psc=1) one and make sure you are only burning wood less than 20% moisture content. The meter is especially important if you run short and end up purchasing wood. Wet wood suuuuuucks. Lots of smoke/creosote and not much heat.
Seasoning really begins when the logs are cut and split. Whole logs laying on the ground dont season well.
Last, if you've never dropped a tree on your own, get help. It's more complicated than it looks and you can get hurt badly especially when cutting down trees that are dead or have rotten spots in them.
I bought this moisuter meter for $22 on Amazon.
I tried to buy firewood last week and told the guy, "We're just about out of wood for this season. We've got some more wood, but it's too wet to burn now. Do you have anything we can burn next week?" Guy says "Oh yeah, you can burn this stuff today if you want."
He showed up with the first truckload of a cord of wood. I said, "Excuse me for testing, but..." and I stuck the meter into one of the pieces of wood. 37%! That's wetter than what I cut last month! He seemed surprised and curious about what a moisture meter was. I think he had felled it last year and just assumed it was dry, but I don't think he had bucked it until quite recently. I don't need to sort out his intentions, I just brought him to my pile and showed him what seasoned firewood measures at.
If you're burning firewood, a $20 moisture meter is a lot cheaper than dealing with an unexpectedly wet load of wood.
Two options:
A wet wood stain.
http://www.davlaurcoatings.com/Products/
Never used before not sure of it's quality.
Or buy a moisture meter and check the levels before you stain. Follow your stains recommendations.
General Tools MMD4E Moisture Meter, Pin Type, Digital LCD https://www.amazon.com/dp/B00275F5O2/ref=cm_sw_r_cp_apa_WjevzbDDWQ12J
If you don't have the wood yet you might be in a pinch. I burn wood to heat our house all winter, but definitely not anywhere near -30c. How much wood depends on the type of wood. Each species has a different BTU rating. Some burn hot and fast others are low and slow. I tend to use both. I like Poplar to get the stove warm and Oak to bank it all night.
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I cut my own wood but if you don't you will need to be careful of sellers saying it is seasoned. A true seasoned piece of wood will be cut and split (generally) for a year. Some sellers will cut and split in the late spring/early summer and try to sell it in the winter. That won't cut it for most guys burning wood. I highly suggest investing into an inexpensive moisture meter. Split a piece of any wood that you are buying and test it. I try to burn at 20% or less.
Also, it might be really helpful for you to get a wall mounted propane heater. They are inexpensive (under $150 at the local big box store or on Amazon). Keep it on a thermostat to kick on if the wood fire goes out. Really helpful on punishing days. If you get the smaller 100 lb tanks you can take them to the filling station and have them filled cheaper than delivery.
Oh and get a carbon monoxide detector. If need to make sure you have enough fresh air in your house to support your wood burning stove and your ability to breathe!
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Wood Heat Value Comparison Chart
Cheap acurite temp/humidity sensors. Use an rtl_sdr to capture the data and use rtl_433 software to decode it.
These
And
This
With this software
https://www.amazon.com/General-Tools-MMD4E-Moisture-High-Medium-Low/dp/B00275F5O2/ref=mp_s_a_1_3?keywords=wood+hygrometer&qid=1574491824&sr=8-3
Get a couple of carpet fans and bring those down with you, these will aid immensely in getting the place dried out. I'm sure they're hard to find in the Harvey-hit areas right now. Check local Craigslist, also rental places will often sell their old ones for $100 or so. One carpet fan can do the work of 20 regular house fans.
As you probably already know, carpet, wiring, drywall, insulation, cabinetry, baseboards that got wet, these gotta go. Studs and other framing members will generally be fine once they dry out, but you have to make sure they're good and dry. You can get a pretty cheap moisture meter on Amazon to help determine when the wood is dry.
Looks like surfactant bleed from high humidity following painting. Kilz it and repaint it.
You can get an inexpensive moisture meter to put your mind at ease.
I am using this one - General Tools MMD4E Digital Moisture Meter https://www.amazon.com/dp/B00275F5O2/ref=cm_sw_r_cp_api_i_pPZUCb9ZJ61GB
Buy a kit to find out if it is really black mold. Just becuase its color is black does not mean its "black" mold.
http://www.amazon.com/5-Minute-Home-Aspergillus-Penicillium-Stachybotrys/dp/B006JAERJK/ref=sr_1_1?ie=UTF8&m=A2IPZHTEAJ3FQ3&s=generic&qid=1327725345&sr=1-1&gclid=CICg_rngxsQCFQgyaQodAbMAmA
If they were freshly slabbed and not kiln dried they would need a year or two of air drying. You can ask the seller, or just get a moisture meter for like $15.
I run a RTL-SDR dongle plugged into my hass server. It runs a nice little program called rtl_433 that decodes the 433mHz signal from an Acurite temp/humidty sensor. Acurite makes a couple different styles, but I use one like this since it's outdoor rated and has great battery life (I'm getting close to 2 years now on the first set of batteries). It has been an absolutely solid setup. I just finally ordered a second sensor to toss in the mix so we shall see how that goes. I plan to use them for non habitable area monitoring (garage, attic, crawlspace, etc).
Ya'll need one of these: https://www.amazon.com/Moisture-Meter-Light-Test-Function/dp/B007FMVOVK
I had not tested it since I don't have a moisture meter (thought they were more than they actually are, thank you for the tip!). I'm going to buy this one and I guess I'll find out in 2 days what its condition is:
https://www.amazon.com/General-Tools-MMD4E-Moisture-Digital/dp/B00275F5O2
Start at the bottom. Mold needs moisture. Water tends to move down and pool. Moisture meters are not too expensive these days.
I think this is the one we used. We gave it away when we were done so I can't say for certain. Just make sure it has the probes like this one. They are fairly cheap. We bought a couple of them and compared. The ones that do not have probes show a much lower moisture content which is not ideal
Test for mold. See if the house has a warrantee on it.
http://www.amazon.com/General-Tools-Instruments-MMD4E-Moisture/dp/B00275F5O2/ref=sr_1_1?ie=UTF8&qid=1450843475&sr=8-1&keywords=general+moisture+meter
Been using it for years. Never found a species it didn't work on.
something like this:
moisture detector
thats why i ended up buying a bunch of these then use an sdr, rpi, and a docker container to graph it all including the floating one in the pool and dump it to mqtt which gets picked up by node-red and into influxdb.
i also have the accurite weather station with the hub thing, but it has a device limit, and you can't get data out of it so that sucks. just much easier sniffing 433mhz if you want the dockerfile i built for it i'll be happy to send it.
Be sure to check You Tube for proper use. Just like a hand plane, card scrapers can be improperly used resulting in folks dismissing their ability. I flex mine slightly like a "U" shape and pull it towards me (paying attention to the grain so as to not dig it in).
Roamins note on quality of wood below is a good one. Soft wet pine will be difficult no matter what. You might consider purchasing some wood and letting it sit stickered (with spacers) for a while to help air it out. If you want to be completely anal about it you can test moisture content with a moisture meter which measures electrical current between 2 points through wood. http://www.amazon.com/General-Tools-MMD4E-Digital-Moisture/dp/B00275F5O2/ref=sr_1_1?ie=UTF8&qid=1321899651&sr=8-1 You’re looking for the wood to stabilize to your environment. Home Depot likely buys bulk from else ware and ships to your area meaning the wood will not only be green (recently cut) but will also be incredibly out of whack with your local humidity. This is why you see crazy warped boards at most big box stores.
Down the road you can look into buying from places with kiln dried and/or stabilized wood. I have the luck of living near a word supplier that ships all over while maintaining a store front for walk ins. Their stuff is great. http://www.woodworkerssource.com/ I suspect most larger cities have similar places (woodcraft being a large multi state business).
Black mold can cause serious healthy problems. There are mold test kits you can get at hardware stores/Home Depot/Amazon.
Fungus and mold thrive where there is moisture and poor ventilation.
Did you see the movie Alien? It's exactly like that.
http://www.amazon.com/gp/product/B002JPB30U/ref=ox_sc_act_title_1?ie=UTF8&smid=ATVPDKIKX0DER
soil pH tester/moisture meter.
it may not be digital but it's better than those fucking strips haha
firewood moisture meter this a tool or instrument to give you the information you need. We moved in to a new to us house and the fire wood we get has a higher moisture content than I want. We made a wood dryer for the first fuel of the day. Wood dryer detail
You are doing nothing wrong. You simply need more information on what works and what moisture content burns well. A high moisture fuel will sit and not burn until the water has been baked off then start releasing heat.
Take the guesswork out of the equation:
Get yourself a moisture meter, e.g. http://www.amazon.com/General-Tools-Instruments-MMD4E-Moisture/dp/B00275F5O2/ref=sr_1_1?ie=UTF8&qid=1413946225&sr=8-1&keywords=moisture+meter
The two things that jump out are the downspout on the right and the windows. It's a bit difficult to tell how the roof goes there, but it looks pretty tricky and then that downspout appears to dump water right on the tricky spot - all of the downspouts need short extensions to get the water away from the corners.
Also, where the end of the gutter is right up against the side of the house. Is the gutter cap well sealed? Does the siding run behind it or did they gutter first then cut the siding around the gutter?
The windows look nice with the wide flat white area around them, but what material is that? How is it flashed to the top of the lower window, how is the upper window flashed to it? It's really difficult to build out a detail like that and make it waterproof.
You'll know more if you can figure out how high up the leak is - yes, the water can very easily move down through the wall. A moisture meter is inexpensive. Read the sheetrock inside just above the baseboard where the water is worst. Read the wall up the side of the window trim on both windows. You may get a clue from that.
It's a bit more money, but you can get Flir 1 for your cell phone - iPhone linked, but there's an Android one too. Take a look at the walls from inside and the ceiling and the side walls of that section. The moisture alone should make for cold spots, but it might be especially obvious on a cold, rainy day. Good general contractors have both moisture meters and Flir 1. Any friend that's a fireman probably has access to a Flir camera. A good home inspector has these tools. I'd offer to help, but I can tell from the architecture that you live nowhere near me.
Please update us later.
I have this moisture meter. It's done well measuring some lumber that is quite wet (~22%), but this is the first time I've bought lumber from an actual lumber mill that kiln dries their wood. The guy at the mill says they dry to 7%. I can't get a reading above 1% at any spot in the wood and at any depth.
To add, the boards milled well through the jointer and the planer with no tear out. However, the resulting sawdust was quite fine and the planer chips were a little brittle.
I'm learning so much! Thanks everyone.
Any devices that y'all recommend to get an accurate reading of Ph levels?
This from Amazon looks good, but some of the reviews make me hesitate to purchase.
You can use these with a RTL-SDR setup. It's well supported in linux.
Why wouldn't a very cheap one do the trick? I'm considering picking up this one personally, unless someone makes a compelling argument to spending more money.
It's pretty much impossible to find seasoned firewood... people say its seasoned but their full of BS. Build a rick and buy in the spring.
Save yourself some trouble and get a wood moisture tester for $15 - https://www.amazon.com/Proster-Moisture-Handheld-Detector-Measuring/dp/B01MV3PSF6/ref=sr_1_1?keywords=firewood+tester&qid=1571346892&sr=8-1
If it reads above 20% just walk away.
I think you have a leak within the wall. You need to verify it, though. Pick up a budget moisture meter: https://www.amazon.com/General-Tools-MMD4E-Moisture-High-Medium-Low/dp/B00275F5O2
Then you'll know for sure.
Do you know what kind of moisture meter they use?
Like this: https://www.amazon.com/General-Tools-MMD4E-Moisture-Digital/dp/B00275F5O2/ref=sr_1_3?ie=UTF8&qid=1505249720&sr=8-3&keywords=moisture+meter
or this: https://www.amazon.com/General-Tools-MMD4E-Moisture-Digital/dp/B00HARYVUQ/ref=sr_1_3?ie=UTF8&qid=1505249720&sr=8-3&keywords=moisture%2Bmeter&th=1
Your post says soil humidity but you should clarify a bit more.
If you are looking for sensors that measure air humidity, you can easily use a DHT11, DHT22, or for more precision a HTU21DF. If you don't want them to get wet then simply come up with some sort of enclosure (Tupperware, empty yogurt container, whatever) drill some holes for ventilation and put the lid on, with adequate holes it can still read humidity and remain dry.
If you mean soil moisture, then you can buy one of those moisture sensors (like this https://www.amazon.com/gp/aw/d/B00AYCNEKW/ref=pd_aw_lpo_328_lp_img_2?ie=UTF8&psc=1&refRID=G9FJ3BJ3B69VC9XKCVA3) and just... Well... Stick it in the dirt. Done.
If I haven't answered the question then let me know!
Sorry for link formatting, am on mobile and too lazy to look for code.
For $13, it's worth the joke tbh.
My girlfriend might roll her eyes at the pun.
Unless the OP has built the deck in a arid mostly dry area with little to no rain/snow all a moisture meter will do is tell the OP when the moisture has dropped below the percentage needed for sealing. Climate wise, a few things are needed to be present; low humidity, dry and warm conditions above 60F (during the daytime hours). In order to hit all three currently, due to the season(s) we're entering,
currently waiting is warranted.
As to the moisture content, depending on the wood used I'd use a higher percentage for moisture content to be below 15% for kiln dried lumber and less than 17% for pressure treated lumber.
If the OP wants to get a moisture meter, they can get one from Amazon for less than $30.
https://www.amazon.com/Wood-Moisture-Meter-Detector-Pin-Type/dp/B07Q5TFB74
Non-mobile: Moisture meters
^That's ^why ^I'm ^here, ^I ^don't ^judge ^you. ^PM ^/u/xl0 ^if ^I'm ^causing ^any ^trouble. ^WUT?
A moisture meter for wood is cheap $15. 12% is good. In the sun they may get even drier and shrink more
I am not sure if this will work, I just looked on amazon for a soil ph tester it’s really cheap and it will give you an idea is you have to something or not.
You may want to get a good fertilizer either way if the land was covered in weeds before.
Try this one. Seems to have a favorable review.
General Tools MMD4E Moisture Meter, Pin Type, Digital LCD https://www.amazon.com/dp/B00275F5O2/ref=cm_sw_r_cp_apip_qASta5WqyE9xo
But this is bad if I get my wood wet (maybe over 25% MC would be considered wet). So I f I get it wet, it stays in my garage until it dips below 20%. Ambient air humidity where i live is (NE USA outside PHILA) about 15%. Once it dips below 20%, I move it into my basement. None of my projects (as of now) will be stored or placed outside. If it was an outdoor project, I would imagine outside is where I would be storing/ working on my of the projects. But since I do indoor work, I move the wood into the basement to be stored at the right time. Then when the MC gets below 10% I generally will work with it, depending on the species and my time table, and whether or not the are paying me (hahaha). Obviously, if I brought it down to the basement to quickly, that’s when problems happen.... but to me, woodworking is more about learning. how to fix your mistakes. So if there was checking or warping, knowing how to fix it, or hide it is crucial. Sometimes hiding a mistake can make the workpiece even better. Bear in mind, that I do not have a big basement so I do not work with big pieces. Big pieces I would imagine are harder to maintain and harder to hide mistakes.
I have an ongoing set of playlists on my YouTube that has helped me, one is one wood drying. If I remember led to save the video to this playlist after I watched it, then the good information is stored there...
Here is the link...
https://www.youtube.com/playlist?list=PL7Ur9yvX0sMRw1UhH9CYeIcyAhW8pVRHq
Feel free to check out the rest of the playlists. I am still in an ongoing process of adding to them.
BTW - you will never get the MC to 0% with standard drying techniques. As long as earth has an atmosphere and there are oceans, there will be MC in wood. this to me seems completely unnecessary and impractical, although I am sure someone will argue with that cause woodworking is very dynamic and full of opinions! Hope this helps!!
I use one of these. My rule of thumb is that typically fresh wood is 25% (wet?) and you want stuff to be in the 5-10% range. I think this can take 6ish months but it depends on humidity, thickness and how you store the wood. I have a big rack of oak slabs that I stacked with sticks in between. I'm no expert though.
In the basement? Something like this.
In the wood? This.
If your basement is constantly humid, plumb in a dehumidifier. However, in doing that, you may want to wait for it to stabilize and then re-acclimate the wood.
Yeah, sorry, no good news from me.
http://www.amazon.com/5-Minute-Home-Aspergillus-Penicillium-Stachybotrys/dp/B006JAERJK/ref=sr_1_1?ie=UTF8&qid=1408588717&sr=8-1&keywords=mold+test+kit
Sometimes it is just easier just to buy
https://www.amazon.com/AcuRite-06002M-Wireless-Temperature-Humidity/dp/B00T0K8NXC
You can check it for moisture by using one of these,
https://www.amazon.com/General-Tools-MMD4E-Moisture-Digital/dp/B00275F5O2/ref=zg_bs_553270_1/147-4890196-7509912?_encoding=UTF8&psc=1&refRID=HMG2MAN2HSF6RCQZ1VZN
Here's a link:
https://www.amazon.com/SUNKEE-Soil-Hygrometer-Moisture-Sensor/dp/B00AYCNEKW%3FSubscriptionId%3DAKIAILSHYYTFIVPWUY6Q%26tag%3Dduckduckgo-d-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB00AYCNEKW
Thanks! I'm more than happy to answer any question you have about my setup.
So I'm using the RPi and controlling stuff using the Wolfram Language. With one line of code I can turn on/off the lights or read/write to other devices/sensors.
For temp/humidity I'm using the DHT22 sensor.
Hygrometer is this one
And light sensor
I setup some cronjobs to control the lights.
It's still in beta shape. Lights are working but I still need to automate the other sensors.
I'm not using an Android app. What I'm thinking is adding to my code some lines to publish my stats in the Wolfram Cloud so I'll always have access to a log/dashboard online.
Hopefully just bad workmanship. Might be worth picking up a moisture meter to verify that you don't have water getting in through the roof/attic
General Tools MMD4E Moisture Meter, Pin Type, Digital LCD https://www.amazon.com/dp/B00275F5O2/ref=cm_sw_r_cp_apa_MQV1Bb6X2HRQY
> professional to look at it?
Probably not, but you'll want to get it dried up ASAP. It can mold if it stays wet for a day or two. Especially if you have sawdust in the cavities. Drywall can dry out pretty quickly, or it can grow nasty mold if it doesn't have moving air to dry it.
I had a similar leak and I drilled several 1.5" holes in the downstairs wall and pointed a fan into the holes. I read that insulation doesn't dry out and I freaked out and pulled out the whole drywall panel a day later — but it was completely dry by then. You just need to force air through any wet cavities. You can rent high volume blowers at big box hardware stores or tool rentals.
Consider removing the affected baseboards to facilitate airflow.
If you like tools, you can get a moisture meter to verify that things are drying out.
There are basically 4 different sensor categories for my application.
  
1. USB logger
This plugs directly into the USB port on the Mac. They range wildly in price, sometimes costing close to $1k (which is way out of my budget).
Examples: TEMPerHUM, Omega, Lascar, Extech, TemperatureAlert, and more here
The problem is that, for whatever reason, these USB loggers are only compatible with Windows. The five above examples are Windows only.
The only logger that I have found that is Mac compatible is the Minnow. However, I spoke with the manufacturer and realized that it is not designed to be a real-time USB logger; the unit will quickly overheat. The workaround is to incorporate a USB relay switch to manually connect/disconnect the Minnow periodically from the Mac.
  
2. Bluetooth
Examples: Blustream, SensorPush, D'Addario Humiditrak, Eve Degree, and more here
The problem is that all of these products have an iOS app, but no macOS app.
But If I purchased the SensorPush sensor along with the $100 SensorPush WiFi Gateway, I can access the data over the internet.
But there are cheaper WiFi options, like the ConnectSense (won't be shipping until early 2019), Proteus, and La Crosse. But, I am hesitant to fully depend on an internet connection to get the data (i.e., if the internet goes down, then I would lose access to the data, which is not ideal).
  
3. RF
AcuRite sells a $13 Wireless Temperature and Humidity Sensor (model # 06002M) that transmits every 16 seconds using a 433 MHz wireless signal with a maximum range of 330'. This sensor is inexpensive because it is designed to be used with AcuRite Access and the AcuRite weather station products, which I do not want or need. It's all proprietary.
However, some people have reverse-engineered the radio signal to decode the data stream from this sensor if you have a USB RF receiver.
Examples:
This path appears frustrating and difficult to a neophyte like me.
  
4. DIY microcontroller
Unlike the other 3 sensor categories, this looks like the one area where proprietary protocols are not in the way of progress. Once you get everything set up, accessing the raw data is a breeze.
This is probably the most cost-effective option.
Examples: Raspberry Pi + this $10 DHT22 sensor, Arduino, Espressif esp8266/esp32 wifi module
The problem is that this is simply over my head. I have no real experience programming from the command line or really anything other than basic scripts. It would just be best if I paid someone to set this up for me, as I can easily envision myself spending 100 hours on this "simple" project.
  
The slab is about 3" thick throughout. I was told that it dried outside for almost 10 years before being planed and finished, but that was in the Philippines which has a much higher equilibrium moisture content. Also, it was moved from the Philippines to Nebraska. In February. A bit of a temperature change as well.
I bought this $20 moisture meter from amazon, and should be able to report the results this weekend: http://www.amazon.com/Dr-Meter%C2%AE-MD-812-Display-Digital-Moisture/dp/B008V6I840/ref=sr_1_1?ie=UTF8&qid=1458875725&sr=8-1&keywords=wood+moisture+meter
I'm not around enough to do the job myself, and I trust a professional to do the job much better than I. I'll certainly be discussing the options with him though, so I'm very appreciative of your advice. I spoke to a few different people, some who recommended just epoxy and some butterfly inlays in addition to the epoxy. I only got one actual price quote, which was $1,500- that was just epoxy, but of course would include refinishing the table.
You may want to buy a mousture sensor.
General Tools MMD4E Moisture Meter, Pin Type, Digital LCD https://www.amazon.com/dp/B00275F5O2/ref=cm_sw_r_cp_apa_i_mOEvCbX3KNQNX
I have the same ceiling/texture. I have a big water spot from a fixed roof leak. While it was leaking it didnt necessarily feel moist but the meter was a good way to check.
Hey thanks for the quick response! Okay, so here's what I'm looking at ordering. If you could comment that it has all the right components for what you have set up, or if I'm missing anything, or if anything is unnecessary, I'd really appreciate the input!
Here's my shopping cart:
From my understanding with this I should be able to get everything I want, including the data logging/recording to PC.
For your signal strength issue, are you aware of this product at all? AcuRite 06053M Wireless Signal Extender for Sensors
Thanks for your input!
It confuses me because there are 2 sticks for ground
https://www.amazon.in/Absolute-Electronics-Soil-Moisture-Testing/dp/B00AYCNEKW M:
With something like this.. although I hope the inspector has better equipment.
https://www.amazon.com/General-Tools-MMD4E-Moisture-High-Medium-Low/dp/B00275F5O2
https://www.youtube.com/watch?v=p2MMYj9qY9Q
OK. Let's do a quick test:
https://www.amazon.com/Healthful-Aspergillus-Penicillium-Stachybotrys-Consultation/dp/B006JAERJK/ref=pd_lpo_vtph_201_bs_t_1?_encoding=UTF8&psc=1&refRID=1Z8CMY8444APS7DSE25X
It is reliable, and you will hear within minutes "see, I told you so".
Oh ya definitely mildew. And it a lot less than I thought it would be. It'll most likely come off with just a good scrubbing. I highly doubt you have any other moisture problems. But if you want to be extra sure we use a much more expensive version of this https://www.amazon.com/dp/B008V6I840/ref=cm_sw_r_cp_apa_l0KIzbSB2HS4T
Is the bathroom on the top floor of the house?
Is there an exhaust fan in the bathroom? If so and it's a older one that's not quite up to snuff anymore I would suggest replacing it or at least cleaning it out.
Lots of good ideas in here, but it just looks over watered at first glance. Gotta really let it dry out between watering. I find these cheap probes do a fantastic job.
I am using a General Tools moisture meter
Go to your local nursery and buy one of those cheap meters.
http://www.amazon.com/Hydrofarm-MGMP1-Active-2-Way-Moisture/dp/B002JPB30U/ref=sr_1_2?ie=UTF8&qid=1342875030&sr=8-2&keywords=ph+moisture+meter
Something like this one. It's not a bad idea to know the ph of the soil too. The general rule of thumb is jamming your finger a few inches into the soil to feel if is moist or dry. If its dry you water. I would rather have a better indication than that so I bought one of these meters. Takes the guess work out of it.