Howdy...A guage or two wouldn't hurt.

However, as far as watering or in some cases, under/over-watering.

There's two ways to check soil.

One is by inserting a skewer/stake deep within soil. Remove. If the skewer is wet/muddy, lower soil is wet. Don't water. Re-check a couple/few days later..repeat.
Wait until the skewer is dry before watering. (depending on plant.)

Ever bake a cake? If so, checking soil is the same as testing doneness of a cake..instead of a skewer, 'for cake,' a tooth pick is used.

The second way is to lift plant before and after watering. When soil is dry, a plant will be light. When soil is wet, heavier.

Testing for pH by using a guage wouldn't hurt. Do you have plants that need acidic soil or just curious?

Sun meters. If you have a really old camera that measures foot candles, it will do...
Search a plant by the amount of light it needs..some sites and plant books discuss foot candles...how much is required per plant.

My meters are made by Rapitest. I don't know if they're the best guages manufactured, but they do work.
Some meters test sun and water or water and pH, so I know they're accurate..or were, I only use these days to test pH.

Guages are sold online from inexpensive to dear prices. Toni

Same reply I left for you at 'the other gardening site':

The inexpensive meters you're probably talking about don't measure moisture, they measure electrical conductivity, and as such are better at determining the soil's fertility level (salt concentration) than its moisture level. To illustrate, dip a clean probe into distilled water & note the DRY reading. Add a sprinkle of fertilizer or table salt & watch it go to WET. The ions in the salt or fertilizer turn the formerly deionized water into a conductor of electricity.

Also, there is very little a hobby grower can do to control pH on a day to day basis w/o a significant array of chemicals that contain nutrients and are either acidic or basic. You can create trends through fertilizer choices, or add acids to your irrigation water that ensure your soil won't creep upward in pH due to high pH tap water, but you'll drive yourself crazzy trying to maintain a stable pH. Also, I wouldn't invest in any pH meter you can't calibrate against a solution of known pH.

My suggestion is, get a wood dowel or bamboo skewer & stick it deep in the pot when you think it's approaching time to water. If it comes out damp/cool/dark-colored from the soil, wait to water. For small pots, feel the soil at the drain hole or heft the pot. If the soil feels dry at the drain or is obviously light when you pick it up (you'll get the knack of this quickly), it's time to water.

Al

I had a moisture meter, worked great.

Meters do come in handy, humans are very poor measuring instruments. But there's a lot of junk being sold out there masquerading as scientific instruments. That's why you need to do a bit of research to find the best for your needs. If it doesn't work or is inaccurate, it's expensive, no matter how low the price.

Actually, when it comes to the inexpensive combination meters you find everywhere for a few bucks, the human finger is a superior instrument for measuring the moisture content of soils, as is a wooden dowel or bamboo skewer; and in most cases where feasible, so is hefting the pot.

Soil begins to feel dry to the touch when it starts to reach about 40% moisture content. Plants can actually extract moisture from soils down to 25-30% moisture content, some even lower. That gives the grower a 10-15% margin for error after the soil feels dry to the touch.

Al

Yes, Al...I was going to suggest the supremely sophisticated digital moisture sensing device (finger)...but people seem so distrustful of it.

Not much good for temps or pH though, LOL.

I don't know (in a musing voice) ................ when I walk outside or into a room and stick my finger into the air, I can usually tell immediately if it's too hot or too cold for my plants. And I wouldn't say there is too much of a difference between my ability to measure pH with my finger and the cheap find-'em-everywhere probes .... they're notoriously inaccurate and can't be calibrated. There are many thousands of gimmicky, near useless things and concoctions out there, waiting to find their way home with the unsuspecting. We're talking about just one that has earned its place that long list.

Save your money - buy a plant.

Al

One doesn't need instruments of this sort to be a successful grower of containerized plants. It's really and truly much simpler than that. Those that really work are expensive and even then, can't tell you anything more than your own senses...common sense AND physical sense.

Both of those skills will be honed with time and experience, but relying on such gizmos will surely dull those abilities.

Rhizo, as I stated above, I have meters, but only use for pH. If then.

Some might feel more comfortable using a guage. For instance, let's say one cannot trust his/her instincts, haven't a clue when to water, unsure about sunlight, feels better counting on a guage, I don't see it as a dependency.

One might start out fiddling w/guages, but after time, reading, research, talking to others on GW, may feel it's time to 'give up the guage.' :) A little Halloween humor.

The point being made is the gauges (cheap ones) are unreliable. If you act on the information gleaned from a gauge, then you're depending on it for guidance. If the gauge is unreliable, you're acting on unreliable information, so you might as well draw straws ..........(IDEA coming) or better yet, use your finger. If you don't trust your own finger, borrow a digital biosensor from a friend/family member. As instruments go, they're quite dependable and easy to find. ;-)

Al

Which has come full circle to what I said above.

How so? Are you familiar with these sensors? ;-)

Al

It's tough figuring out what is the best solution would be. Personally, I would probably just get a ph testing kit at a home depot - it costs just a few dollars, and once your ph is set, it doesn't change very often (unless you add something to the soil). As far as as moisture, I use this soil moisture meter. It has worked well for me as it was in the Goldilocks zone for prices. Rather than costing $2000 as a professional piece of technology, it cost about 80. And it's not like the cheap ones, in that salinity/fertilizer doesn't affect it. As far as light, not sure what to say. It is obviously very crucial to a plant's growth and I know that certain colors of light are more essential than others, but I don't know of an affordable device that works well. Honestly, I think that the natural light of the sun makes the most sense...