How to build a voice-controlled automatic water change system
That title sure is a mouthful, but it’s exactly what I’ve built and I’ll walk through the setup.
My water change system is an automatic voice-controlled water change system that uses fully filtered, heated, aerated water to pump into tanks via a convenient hook, and is capable of switching between filling and draining through the same hose simply with my voice. The result is being able to water change 20+ tanks in only an hour or two.
You Will Need
(Links will be provided in the article)
Around $100 for supplies, which are variable depending on what your needs are. The bare minimum includes:
A lot of hosing, 1/2” ID (inner diameter) is the easiest to use. You can get 100ft on Amazon for under $30.
A Y fitting and an electrically controlled solenoid, both 1/2” ID
A diaphragm pump (for draining) and optionally a sump pump (for filling from a barrel)
A canister filter inlet tube for connecting to your tanks
Two smart plugs and your favorite home assistant
Some sort of water connection, probably from a faucet or toilet cold water hookup
A way to drain your water, probably a bathtub or sink drain hookup or a hose outside
Part 1: Water In
The first step is getting water INTO your system. Before building any of the system, you’ll need to connect your home’s cold water supply to your water change system. There are loads of ways to do this, here’s how I did:
My home already had an under-sink water filter in the kitchen, and my fish room is conveniently only about 30 feet away from my kitchen. I simply split the filtered cold water line, and I ran the split underneath my house and into my fish room.
The simpler, less crazy version of that is to use any nearby sink or toilet and connect into the water line. I’d advise an adapter like this, which taps into a water line and gives you an easy push-connect fitting. Super easy install, just twist off the water valve under the sink/toilet, unscrew the line, screw this in between, and connect everything back up. Then, just run 1/4” push connect water hoses (AKA refrigerator water lines or ice maker water lines) to your water change system.
To Barrel or not to barrel
My system utilizes a 58 gallon barrel to store water before it’s added to a tank. This allows me to pump way more water than the small amount of filtered water I can get from the hose, and it also allows me to treat and heat the water before it’s added to a tank. If it’s at all practical for you to use a big barrel, it’s definitely the best way to go.
If you’re using a barrel, you’ll need a sump pump at the bottom of the barrel to pump water into the system. If not, you just need the water line from your house.
Part 2: Water Out
Okay, now obviously you need a way to get water out. The easiest method by far is simply running a hose to a nearby bathtub sink or toilet and securing it in place with a command hook or something. The cleaner looking method is to run a hose under the house to a drain pipe.
I wound up doing neither, and instead I ran a drain hose underneath my house and out the back of my house into my woods, with the intention on eventually storing the water to water my lawn (or my dad’s “crops”) with. Either way, you’ll need some way to get water out.
And either way, you’ll need a pump to suck water from the tanks. I recommend a 3GPM 45psi Diaphragm pump. Try to keep PSI low, the higher the PSI the more likely it’ll vacuum-collapse your hose. This is the one I use: https://amzn.to/3Nn900R - It’s spendier but more powerful.
I also strongly recommend adding some sort of filter inline to catch the crud so it doesn’t clog your pump. I just use a $15 walmart water filter that I cut the actual filter media out of so it’s just a bunch of 1/4” plastic holes.
The “In” leads from the hose that connects to our tanks. The “Out” leads to the “In” of the diaphragm pump below, and the pump’s “Out” leads outside to the drain.
Part 3: Connecting to tank
Halfway done! To connect to your tank you’ll need a long hose and a hook. This is most easily accomplished with a canister filter intake, I found this one perfect for my needs: https://amzn.to/3Tj2fAU
Simply connect the filter intake to a hose long enough to reach all your tanks from the central water change system, and you’re good to go.
Optionally you can add a few upgrades like I did:
Quick Disconnect fitting to easily connect a gravel vac instead
Easy twist to shutoff valve to move from tank to tank without turning off pump
Smart water leak sensor which notifies me if my tank is overflowing and automates fill shutoff
The Hard Part: Connecting it all together
This is the tough(er) part that isn’t even that hard. To connect it all together, you’ll simply need some basic engineering.
In the end, your system will work like this:
Lets explain each color here.
Green: Water In - Clean, filtered water is coming from the 1/4” line under the sink and is filling the barrel until it reaches the top (using a float valve)
Blue: Fill - Clean, filtered, heated water from the barrel is pumped out, through the (cyan) solenoid which is open when filling, and to the tank.
When the fill water hits the Y intersection beneath the solenoid, it always goes down (to the tank) due to gravity, so you won’t get clean water draining.
Cyan: Solenoid - The most important part of the setup. This is a valve that is electronically controlled. It is powered, and open, when filling and unpowered, and closed, when draining. This is crucial to ensure that dirty water only goes to the drain pump, and it doesn’t suck in clean water.
Brown: Drain - Dirty tank water out. The water is sucked from the tank, through the Y, and will always go right because the solenoid on the left is closed when draining. It intentionally goes through a high loop to keep air bubbles out of the pump and to keep the fill pump from draining water. Then it goes through a water filter, and finally the pump which pumps it outside.
That’s all the plumbing! And for electrical…
Electrical is super easy. You just need two smart plugs and one power strip or plug splitter.
You simply want to set up one smart plug as “Fill Pump” and plug in both the solenoid and fill pump (if used). And set up the other plug as “Drain Pump” and plug in the drain pump. Hook these both up to a google home (or Alexa), and you’re golden.
Use:
With the system done, here’s how to use it!
Simply hook your hose onto any tank, the nozzle is adjustable for different heights of tanks too. Say “Hey Google, turn on the drain pump”. Watch as the pump kicks on, sucking water through the nozzle, through the long hose, and out of your home.
Then, once the tank is low enough, ask google to turn off the drain pump and turn on the fill pump. Instantly, the system will reverse directions. The solenoid will open and clean water will rush into the tank, filling it right back up.
Then, when you’re done, just shut off the fill pump and go onto the next tank!
Automation:
I’ve automated mine even more with some other cool stuff.
I set up a smart water sensor on the tank hook, and glued the sensor right at the water level where the tank is about to overflow. When triggered, it sends a notification to my phone. I used IFTTT on my phone to make a simple automation that turns off the fill pump whenever it receives that notification, so no matter what I never have to worry about flooding the room.
I’ve also used IFTTT and Tasker to schedule certain tasks. If I trigger “10 gallon waterchange”, the system is set to run the drain pump for around 60 seconds, enough to drain a 10 gallon tank about halfway, then to run the fill pump until the water sensor shuts it off. I use this for different tank sizes, so with one statement I can have the system fully drain and fill any size tank I have.
