Liquid level sensor and controller (auto top-off for aquarium)

[@AppliedScience]

I use both imperial and metric units. In fact, I was criticized in another video for using imperial too much. Metric is obviously a better system, but the USA is so entrenched, it's difficult to switch. You're right about the angle. It should be 90 for best performance, but other angles work too.

[@TheCrazyInventor]

What a neat and elegant way to measure the water level. Never thought of that myself.

[@AppliedScience]

The key thing is the difference between refractive indices of the prism (acrylic plastic) and the medium surrounding it. If the medium is air, light will be reflected internally, and the pump will be activated. If the medium is water (or non-transparent like calcium or algae), most of the light will be scattered away and the pump will not be activated.

[@garmse]

Today I went to my University to ask about a level controller. Could've waited to see your video and all my doubts would've been solved in les than 10 minutes. Anyways THANK YOU so much for your videos, I totally love them.

[@KB9ZWL]

The FSV-11 is a very good sensor When I was working in the Food manufacturing industry we used a lot of them for sensing product motion and conveyor control. I installed them in a lot of different applications. One packaging machine had a bank of 20 of them fun times.

[@gricka31]

this guy must be the best employee. he solves EVERYTHING

[@adisharr]

The ambient light rejection is done by modulating the light source at a specific frequency and then using a narrow filter for that frequency. That way it can reject common household and industrial light sources. In the case of using multiple units in close proximity, many of the newer types can be connected as shown in the upper left of his video which can then be sequentially activated to avoid interference.

[@evinism]

I think I'm more excited when one of your videos go up than pretty much any other. I've learned so much from these. Thanks for being a boss at things.

[@dtopham100]

Very cool! Things like this make me wish I had paid a bit more attention in science classes. It is nice to see practical uses for these ideas that seem so remote in the classroom. Keep up the good work, Ben!

[@morbos]

Thanks Ben for another great vid! This is not unlike the rain sensor for car windshields. The drop of water changes amount of light on the sensor.

[@monkeyvoodoo9052]

Awesome! I have water problems in my basement during the winter, and have been trying to come up with a reliable way to turn a pump on and off without spending tons of money, or needing a float switch (which needs a fair amount of vertical space to activate, which isn't desirable as far as keeping my basement mostly dry goes). I always find your videos interesting and informative, but this one looks like it'll be super useful for me. Thanks!

[@AppliedScience]

Sure, that would work. One problem is that I don't want metal exposed to the aquarium water -- especially metal that is routed into the same electrical box that has mains voltage. The optical approach is inherently safe, and immune to corrosion as well.

[@n17ikh]

Neat! Total internal reflection is how rain sensors on luxury cars work for automatic wipers, a wet windshield reflects light differently from a dry one. I've toyed with the idea of making a rain sensor for my car to put the convertible top up if it starts raining, maybe I'll buy some of the Keyence sensors from ebay to test it out.

[@tothemaxttm]

surplus suppliers can be wonderful places to find this kind of equipment. DC power supply may be thousands brand new, but used ones often wind up in a junk heap then to a surplus place.

[@AppliedScience]

I believe they do have a semi-configurable de-bounce timer. The pump that I used can be cycled rapidly since it is just a reciprocating diaphragm pump. It is also super quiet, so I can't tell when it is bouncing on and off.

[@felixthecrazy]

Way more wicked and complicated than my float sensors. Awesome.

[@owovergrowth]

To make the light refraction thing a little more complicated, changing the n value of the outer material (i.e. water/air) will change the angle at which total internal reflection occurs (it's 45 degrees for acrylic in air, a different value for acrylic in water, which allows the light to go right on through the acrylic and into the water, giving a smaller reading back.

[@user-xb5zu6zu7j]

You saved my day- that's exactly what I've been looking for. Big thanks for the video.

[@ajscomp372]

Turns out you don't even need to make the acrylic sensor tip yourself if you don't want to. Keyence sells the FU-93/93Z/94C, which is basically the same as your homemade sensor tip, or the FU-95 series, which looks through the glass (or clear tube/pipe) to get liquid level.

[@spokehedz]

Floats can be gummed up real easily with the algae and high mineral contents that are in water. I would be willing to bet that hydro unit will not perform as robustly this one does. Not only that, with this same unit, he could technically also have it sense when the water becomes cloudy and set a light off that reminds him to change the filter--or even dose out a bit of algae killer automatically. And a whole load of other things all with the same unit.

[@y1hardtop]

Since water is slightly electrically conductive, a much simpler method is to use a hexfet and a couple of resistors, for a water level sensor.

[@adisharr]

Also, you don't need any jig to polish plastic fiber. Simply snip to length with a sharp razor and then polish against any hard surface. They are very forgiving.

[@502deth]

iwont argue weather or not its a "better" sys., but, in my area, just try to find any metric taps, dies, drills, tape measures, ect.. at your local hardware store. if your lucky, they will have a small selection of metric bolts. any thing else is order online and wait for it to ship. great vids, btw. been going through them today. found you through the designing a transistor switch circuit vid. thats what i need to know. every other video is theory. i need to see the hands on to understand

[@SireSquish]

One thing that makes me wonder about this probe: anything in an aquarium that is permanently immersed will tend to attract algae or other debris. I can imagine a situation where the light will be absorbed by whatever is fouling the probe, causing the pump to overflow the tank with excess topup water. I know you addressed this in the video, but that probe looks really quite clean compared to any long-term immersed object in my tank. That said - when are these going to market? :)

[@tharlowXY]

Inspired design, but most importantly it looks cool.

[@subi7o]

You make everything extremely interesting.

[@404nf1]

You should do a video on where you got all your tools at, over the course of watching these I've seen tens of thousands of dollars worth of equipment in the background. Stuff I would chop off my left foot to get a hold of.

[@Cameron_J]

I started watching your videos and half way through realized you have a reef tank. I don't see much on it though. This would be perfect for my system. You should have opened up the outlet box in the video. I don't have a cnc or lathe so making that end cap is not possible for me. Most ato are float or ultrasonic or even pressure/weight based. This is nice. Would love to get one

[@AppliedScience]

Cameron Julsrud Thanks. I have had a few 55gal saltwater tanks, and a few small (5gal) reef tanks in the past, but nothing at the moment. It's true that an optical, low-cost liquid level sensor would be great for small home aquariums.

[@MrEwilliams2]

Do you have a diagram for how you wired this? What kind of relay did you use in the box? I built a similar sensor, but i want to see the signal in arduino if possible.

[@chiphill4856]

Nicely done!

[@Inspironator]

that acrylic tip is not a 90 degree angle...But very nice implementation of the technology.

[@jeremiahblatz]

Why did you choose a solid state relay, out of curiosity? It seems like a mechanical relay would be superior in this application. Does the sensor not supply enough oomph to trigger a mechanical relay?

[@jeffjohnson6401]

Could this be used in a pool? How do you think the acrylic sensor would stand up to Chlorine?

[@TestSubject2000]

Hi, Love the idea! Great application of fiber optics. Would you think this concept could be used as a monitor for precise water level monitoring (graduated rather than On/off). Maybe by using a U shape acrylic rod with input at one end and output at the other?

[@shanereinholdt1526]

Hello Appiled Science, Great video, fantastic idea on monitoring/ controlling water levels with a non-mechanical moving device. Such as a float switch that undoubtedly in the long run has a 100% failure rate {often sooner than later due to gummy, crusty, crud build up(s)} My assumption are: 12v Auto Relay & 120V aquarium water pump Question: What is the required voltage of the senor device? Low voltage I presume, and hope. Since my application is an off grid happening. Thanks, Shane

[@KowboyUSA]

Where did you get the heater strip you used in your 'A close look at supercritical carbon dioxide CO2' video? I desperately need one for a project I'm working on.

[@mikeg4972]

Can a sensor like this work in the dirty/ rusty environment of an automotive cooling system? I'm looking for a coolant level sensor that has no moving parts.

[@grundel_live]

I found the Keyence FS V11, what brand/model is the actual sensor that goes towards the water, or does that come with the keyence?

[@JosephMassimino]

I bought 6 of them New, for $20, on a accepted best offer, and free shipping. Do you have any suggestions for me to turn my toslink cable into a sensor like what you turned on a lathe ? I don't have a lathe to do that?

[@actioncia]

I can just use a 12 vdc relay with a 12 v power source to power this controller than when zero water is detected, it turns on the power head from reservoir for water?

[@613joy]

I like this idea better than the float switches. How do you mount it?

[@aerofart]

Ben: Do those sensors have a de-bounce feature? Is there a problem with your water level probe turning the pump on and off repeatedly when the sensor is near threshold?

[@barneycarparts]

Hello Applied Science, Can you do a video on a similar device to sense water color. I have a gunite pond I put a blue dye into to stop algae growth. The blue color fades within a couple of days and algae begins to bloom. I would like an automated gizmo to keep it at the same shade of blue. I am proficient in Arduino programing in C++. I thought I could do a photo sensor and red led looking through a glass tube. Looking for ideas. Thanks.

[@jy_smile6689]

barneycarparts hello, im interested in your project on sensor to detect color change in water. Can you help me with that? Tq

[@frac]

Not a GFCI on an aquarium plug? Or is it plugged in to a GFCI circuit?

[@Nikkuuu69]

Could you also mount 2 metal pieces next to each other (with a gap of course) and detect if the water conducts current between the two?

[@sd4dfg2]

If calcium and other external buildup doesn't reflect/refract the light away like water, then doesn't it refract like air? Which is the condition that turns the pump on to fill your tank?

[@Nikkuuu69]

That's what I was thinking as well, thanks for the reply ;)

[@502deth]

i notice a lot of metric references in your videos. canada? also, i dont know how metric angles work, but im pretty sure, even in metric, that cone is not 90 degs ;)

[@revolutiongames2004]

You should hook it up to a feeder to feed while it fills.

[@davidmorrill2943]

A wise man once told me (paraphrase) a true sign of genius is that a real genius can get the same result a "genius" with much more simple methods.

[@POLOLOUS3]

How about a simpler setup like water sensor to turn on a pump?

[@martygermishuys2350]

can you show me how you wired up the relay?

[@ViperMD]

Excellent video. Watching these always makes me want to do projects, sadly I never know what to do. lol Also that 1 dislike must be a luddite.

[@ankeshjaisansaria4688]

From where can I get this sensor ?

[@HerringZFish]

Would anyone entertain the idea of making one of these thing for sale? I think that I would need is the sensor, cable and Keyence, not the relay or AC outlet. I would hook that to a controller.

[@TheMBagge]

The datasheet says max. current consumption 50mA

[@datsquazz]

This would be cool for pc liquid cooling

[@paulbendel]

Cool!

[@randalbarrett9600]

Are you still monitoring this? I have a few questions. I am going to use this simple method to see a dark liquid level through a glass tube. I am wanting to pick your brain :) I am a scientific glassblower. Randal

[@tuva600]

THE MORE YOU KNOW!

[@Loompia]

'Project that resurfaced', lololololololololcats.

[@seongwonchoi]

CLR