---
title: 'Video Q9fjKeYOyqU'
source: 'https://youtube.com/watch?v=Q9fjKeYOyqU'
video_id: 'Q9fjKeYOyqU'
date: 2026-07-02
duration_sec: 996
---

# Video Q9fjKeYOyqU

> Source: [Video Q9fjKeYOyqU](https://youtube.com/watch?v=Q9fjKeYOyqU)

## Summary

The video presents a DIY automation system for a 4x4 grow tent, built over a year using Home Assistant, sensors, and pumps. The creator aims to eliminate human error by automating water, nutrient, and environmental control. The system includes a reverse osmosis water supply, mixing reservoir with weight-based measurement, and flood detection for safety.

### Key Points

- **Home Assistant as central controller** [07:32] — The system uses Home Assistant running on a Raspberry Pi (later upgraded to a desktop) for automation, with sensors and relays controlled via ESP32 and Arduino Mega.
- **Water and nutrient delivery** [01:23] — Water flows from an RO system through a solenoid valve into a freshwater reservoir, then to a mixing reservoir where nutrients and pH are dosed using peristaltic pumps.
- **Weight-based volume measurement** [03:21] — An Arduino scale measures water weight to determine volume, replacing unreliable e-tape sensors.
- **Tent environmental control** [05:00] — The tent uses a Cloudline T6 fan controlled via PWM, temperature/humidity sensors, and a DIY humidifier with ultrasonic disks.
- **Flood detection and safety** [14:27] — Flood detection sensors on the floor trigger critical alerts and automatically shut off water and pumps to prevent damage.
- **Control box hardware** [10:58] — The control box includes an Arduino Mega with a Tentacle shield for Atlas Scientific pH/EC probes, motor drivers for pump speed control, and relay boards for switching.

## Transcript

Hey everybody, hope you're all doing okay out there. I am off work and stuck at home right now, and I haven't uploaded in a gazillion years. So, I think it's a good time to get back into this and share a project of mine that I've been working on whenever I get any spare time.
And I've been working on this for maybe the past year or so. What it is, is a DIY automation system for my 4x4 tent. and I've been completely sucked into this.
Once I started with it, I got so enamored with it and excited by it that I'm just constantly spending time working on this system whenever I get it. It is so much fun to find different sensors and components on Amazon
and try to implement them to try to solve your problems or make things easier for you and try to cut yourself out of the equation sort of because I think that was a big problem and whenever my grows would go wrong,
It would be neglect on my part when you screw something up. So I'm trying to chop myself out of the equation completely, and I'm having an absolute blast doing it with this control system. So anyway, I wanted to show you what I've got going on,
and hear what you guys have to think, see if anybody's doing anything similar, get some maybe suggestions for things that would be cool to do, and yeah, go from there. Starting right from the beginning of the chain,
I have a reverse osmosis system upstairs which feeds down through this blue tube. It comes through a solenoid which I'm using in line just to be able to control the flow of water into the system. So if something goes wrong, I can kill it here and make sure it doesn't continue to go wrong.
That feeds down through into this first res up top. This is my freshwater RO res. So the blue tube comes through a full valve to keep the sink permanently topped up. and then this res is feeding both a DIY humidifier in the tent which is kept
popped up on our float valve and it's also feeding down into my mixing res so to get water from here down to here I was concerned about it pipening so what I've done is put a pump into this thing turn that on I turn on this solenoid as
well and then that allows water to flow down through into here comes through another float valve in this thing and this is where I'm doing all of my nutrient dosing and my pH up and down dosing as well. I have a pH probe from
Atlas Scientific in here. I also have an Atlas EC probe on the other side and a temperature probe and in here I have a couple pumps. One of them turns on every
10 minutes or so and keeps it mixed and aerated and the other pump actually to the plants in the tent. I had trouble measuring how much solution was in here. I had used
a couple different solutions for that that didn't work out. I had used this something called an e-tape, which is kind of like a ruler that senses how much water is on it. It's maybe a foot long. You can get it in different lengths. But I found it wasn't really
as reliable as I had hoped. The readings were kind of all over the place and it just wasn't And so I came up with a different idea, which was to measure it. Since the weight of water is constant, I forget exactly what it is.
I think it's something like 8 point something pounds per gallon. I decided I would just build a little sort of Arduino scale. So sandwiched between these two pieces of wood, I have four weigh sensors.
And that just feeds information back to my controller, which converts the weight into gallons in volume. And it works like a hot damn. And if I press on it just a tiny little bit, it changes right away. And it's very consistent, so I'm happy with how that turned out.
So on the backboard, I have my control box. This thing is just a regular old hobby box that I've modified to fit this project. I also have my mason jars that contain my pH and nutrient solution mounted to the backboard.
And a power strip. And inside this power strip I placed a 4 relay board which allows me to control the bottom 4 outlets independently of one another The rest are just always on But I using these to switch the pumps on and off for my reservoirs all the different pumps
I'm using my system to run this 4x4 tent and this is by far the area that needs the most work. Everything is just kind of temped up right now. Need some love, but hopefully I can get to this in the very near future.
So, first thing you see is this ugly breadboard that's hanging. This has an ESP32 and an 8266. These are both little Wi-Fi controllers.
I can condense this down to one, but I'm kind of lazy because they're both doing two different things, although it could be done by just the one ESP32. I haven't done that yet, but I have two temperature and humidity sensors on this board,
so that's reporting the conditions of the tent back to the controller. and I'm also using the ESC32 to do PWM control of the tent fan. So I have like a Cloudline T6 that I've intercepted the connection from the main controller,
and I'm injecting my own PWM now to control the level. So I just leave it cranked on here, but you can see that the fan's actually off right now because I'm controlling it. So the plants are fed by these little spaghetti lines which come off of one half inch line
that goes back to the reservoir. And I flood them five times a night. They drain down through these comically underside bulkheads which have quarter inch lines connected
to them which is way too small. I'm constantly having to unclog it but I'm going to try to upgrade a half inch or something. So that feeds down into this basin, all four of them. And in here, that white thing is the float sensor.
So as the water level rises, it will trigger the float sensor, which tells my system to turn on the pump that's in here, and that will feed back into the reservoir. This is my DIY humidifier.
So it's just a computer fan on this elbow that pushes air through. And inside I have a couple little ultrasonic disks that make the mist. And this thing, as I mentioned, is fed off of my RO reservoir.
So I think that's all that's going on in the tent. I have a lot of work to do with the lights right now. The scheduling is controlled by the system, but I want to do dimming, and I want to have control over, like, a red and a blue channel
that I intend to ramp up and down during the day to kind of emulate sunrise and sunset and whatnot. I've done terrible jobs of managing these tomatoes. You gotta be on top of them or else
they scroll everywhere like this one has done. It is... it's everywhere. It's taken over the tent. This is a bell pepper plant. And this is a Carolina Reaper, which has not yet
made any big peppers, but I'm hoping soon. Before I get too caught up talking about the the control box and all the inner workings and everything, I'll give you a brief explanation of how the thing works from a high level perspective.
My assistant is run off of a program called Home Assistant. Home Assistant is free, it's constantly being worked on and it's got a very large and active community. The forums are a really good resource for getting started or trying to figure out something that you
stuck on. I settled on Home Assistant to run my project because it is very secure, so you You can run it entirely on your own private home network. You don't have to go through the cloud to talk to some remote server,
unless you want to, of course. And also, I don't want to say that it's plug-and-play by any means, but it is pretty beginner-friendly to get into this automation. So you don't need to know Python or C.
You don have to write line code to get into this And it will take some time to get it installed and get it configured and learn how it works and how to work with it but it's well worth it and it's really powerful once you get on your feet
and working with data once it's flowing through your system and writing automations is super easy compared to how it would be if you were writing it in line-based code. When I first started this project, I had zero experience writing code whatsoever.
I have learned some along the way, just studying on my own because it's something that I would like to learn, but it's certainly not a requirement to get going. And I was able to get started just by reading the forums, watching some videos and guides, reading tutorials, and copying and pasting and experimenting.
So, steep learning curve, but you don't need to have anything going into it but the willingness to learn. When I started this home assistant project, I started on a Raspberry Pi, which I think is probably the most common device for people to get going with.
There's a lot of information on the web, tutorials, videos, walkthroughs, for using a Pi to run home assistants compared to, say, using a VM, a virtual machine, or a Linux server or something like that.
Most people are starting on a Raspberry Pi. So if you have the need to do so, I would suggest using this thing to get going. And it'll serve you well for a long time. I ran on this Pi for over a year before I ended up switching to an old desktop that I have.
I found that I had so many automations and so much data moving around that performance was starting to slip a little bit on the Pi. It wasn't quite as snappy as I would have liked. So eventually I upgraded to a desktop.
But that's the nice thing is that you get started on something smaller and cheap, And then if you need to migrate to something more powerful, it's very easy to do so. So here are the guts of the system. Right away you'll notice that it is not beautiful.
I tried to keep it somewhat clean, but it is kind of bush league, like using these breadboards in here. Not ideal for sure. It would be great to have some printed circuit boards, like once they come on shit together and finalize some stuff.
So this is kind of in, we'll call it a prototype. I don't know if it'll ever actually get converted to something more permanent, but it works for the time being. But again, using these breadboards and using like these Dupont connectors, definitely not ideal, but it's my prototype, so whatever.
In terms of like a system hierarchy, the very top would be the Linux server that I have whole assistant actually running on, which fits elsewhere in the basement. And then second in command would probably be this ESP here.
So this processor has a lot of inputs and outputs in this box and it also is in charge of taking information from this other processor, this Nazeen Omega, and relaying it back to the server because this doesn't have Ethernet or Wi-Fi out of the box. You would need like a shield for that.
So it's just communicating with this over a couple wires and broadcasting that information from here plus a lot of other information back to the server so I can read it and act on it and display it.
So the Mega is under here and you can't really see it except for the yellow connectors there. But the thing that's attached to it is called a shield and shields do different things.
They kind of serve specific purposes. This one in particular is a tentacle from White Boss Labs. And its job is to make it easier to interface with my Atlas Scientific probes.
So you get four slots for these stamps they call them. This is the PH stamp and this is the EC stamp. And it sits on there and then communicates over this BMC cable, which I made myself because the ones that you get on the probes are a little bit short.
So I just created a little jumper cable for each one of them. But this goes and talks to that probe and gets information from the res below. And then it spits it out over serial back to this thing So the whole box is run off of this 12 volt mineral power supply and some things need 12 volts like the the peristaltic pumps but a lot of it needs
a lower voltage so I'm stepping it down in a couple places. I'm giving 7 volts to each of these processors and I'm giving 5 volts to most of the other circuitry
in here. A lot of this stuff runs on 5 volts. So at the top these are motor drivers. So these three things are what I use to regulate the speed to the pumps because if you just give them 12 volts then they spin really super fast and it
does not work out for this application because you'd be pumping an absolute shit ton of stuff at a crazy rate. So you have to slow it down and using PWM is a good way to do it. So this controller is providing that PWM signal into each one
of these and I can use that to vary the speed of these pumps. So I can run them say for two seconds, measure how much liquid they're pumping, and then adjust that PWM rate to make sure that they're all identical. And then I just turn them on and off for a
set time to give me a set amount of liquid. This guy is a temperature and humidity sensor just to monitor their conditions in the box. And then this is an 8-channel relay board.
So you use relays to make or break connections. You just turn them on or off and it lets you switch a lot more current than you could just by doing it with the pins on the controller. So this relay board is running my solenoid here, like I'm
providing 12 volts to that, just turning it on and off with the relay, and it's also running my nutrient stirring system which I'll show you in a bit, but I have a lot of spare channels on this one for sure. I have a four channel version of
this in that power bar that I had mentioned earlier. It's just kind of shoehorned in but it looks just like this and it's fun in the same way. So here on the bottom these are moisture sensors and I had initially thought I was going to use
them as truly as a moisture sensor in the different pine pots but I'm just using them sort of as flood detection now so these go out to the field and I have two sensors under here one there and one there and I'm just using it to
detect if anything goes wrong if I start leaking water onto the floor it slopes that way so it will hit those sensors and when it does that immediately it will send a notification to my phone like a critical alert which I just
learned will interrupt the video if you're taking it so I'm not going to test it again not yet but it'll send that critical alert to my phone and it will also kill this solenoid so it'll stop water from flowing into the system and it turns off all the pumps so if there's something that's flooding the
tent or whatever it kills all the pumps in the thing until I come and fix whatever is wrong with it. So I think that's pretty much it for hardware. There
is stuff in the field of course that I'm using. When it comes to turning power on and off remotely like for controlling my light cycle in the tent if I want to turn it on and off. I'm using the EP-Link Wi-Fi controllable outlets so you can
control them with a button but you can also control them through home assistant which is awesome. So this is the green screen lights one here so I'll just toggle it on and off. You can kind of hear it, kind of see it but they work
Awesome. And it's very responsive too. So I have five or six of these in different locations, say turning on a humidifier, turning on the lights, or whatever needs
AC power controlled. So I think that's pretty much it for hardware, like I say. I think I'll go into the touch panel and some of the different stuff that I've programmed into the systems now.
you