a system of aquaculture in which the waste produced by farmed fish or other aquatic animals supplies nutrients for plants grown hydroponically, which in turn purify the water.

Aquaponics @ CRT Labs

The Grove aquaponics set-up for CRT Labs, with kale above and goldfish in the tank.


If you’ve been by the lab over the last year or so, you’ve most likely seen our aquaponics systems. Filled with fish, ghost shrimp, herbs and vegetables, these systems work based on a symbiotic relationship between the aquatic life and the plants growing above. It’s a complex relationship based around the nitrogen cycle.

It’s great having living systems in your office space, but creates an interesting challenge when those living things rely on a small group of individuals that work remotely, travel constantly and in general have a very inconsistent office schedule. Aquaponics systems also have a decent amount of maintenance. More than once we’ve come back to the office after a weekend to find the water reservoirs empty, plants wilting and some very murky water. 

Ironically, for being a R&D technology lab we’ve come up with a decidedly low-tech solution: an Aquaponics Chores spreadsheet. The idea being that anyone can quickly scan the sheet that is taped next to each unit and see what needs to be done that day, and who did the previous day/week/month chores. We’ve broken tasks into 3 sections: Daily, Weekly and Monthly. I want to go over each task and give a little more detail on how it helps keep our aquaponics systems as productive as possible. It also helps spread the knowledge to other members of the lab besides myself, and combats the Bus factor.

Aquaponics Chores

Aquaponics Chore Chart, recently implemented by the labs


  • Feeding
    • Our aquatic friends require sustenance to survive, and this is also the only “input” into the system. To have a truly organic system, you need to use organic fish feed.
  • Water Levels
    • Correct water levels are crucial for optimal pump operation. Low water can also stress the fish, causing shortened lives, disease and eating issues.
  • Pumps are running
    • Just as crucial to feeding the fish is making sure the pumps are running, and not just running, but actually moving water. The only filtration in the system are the plant roots themselves, the fish can quickly die if this part of the nitrogen cycle stops working as nitrite is highly toxic to fish, as is ammonia.
  • Lights are on
    • Plants need light!
  • No dead animals
    • Besides being gross and unsightly, decomposing organic matter can add additional load to the plant root filtration system, sometimes more then your plants can handle.


  • Tank scrub
    • Algae will undoubtedly start forming on the aquarium walls, besides hiding your pretty fish, the algae also extracts nutrients from the water that would otherwise go to your delicious veggies and herbs.
  • PH levels
    • Optimal PH levels are low 7’s, plants prefer slightly more acidic levels, in the low 6’s to high 5’s while the fish and bacteria prefer slightly more alkaline in the high 7’s to low 8’s. So it’s a constant compromise to keep the 2 systems in check. Although once a system has been running for a while the PH levels become very stable, unless there are unforeseen inputs into the system.
  • Nitrgoen levels
    • Since the whole system relies on the nitrogen cycle working efficiently, it’s important to check nitrate, nitrite and ammonia levels to ensure the system is operating correctly.
  • Plant pruning
    • Once the system is up and running, plants should grow quite vigorously. Weekly pruning helps keep the plants in check and also provides fresh herbs and greens for the kitchen.


  • Filter Cleaning
    • I mentioned before that the only filtration in our aquaponics system are the plant roots themselves, this isn’t totally true. The pumps themselves have small filters to keep out large debris that may clog the pump and/or irrigation lines. It’s important to keep these clear for maximum water movement.
  • 25% Water change
    • This isn’t always necessary depending on how often you’re topping off the system, when plants are growing and/or humidity is very low. You may be topping the system off every few days, which is equivalent to 25% water changes every month. It helps keep the water “fresh” so you don’t get to much build up of any one nitrogen process.

We’ve just introduced the task sheet to the lab, and haven’t had much travel/absences yet, but hopefully this will help others understand the requirements of the system as well as keep our fish and plants as happy as possible. If it works out, maybe we’ll “appify” the process and open it up to other aquaponic farmers :). If you have any questions at all about aquaponics, hydroponics or other cool urban agriculture systems feel free to drop us a line.

The Long Road Around The Weather Underground

The year is 2013, I’ve bought a small vacation house in western Michigan, in the country, way out in the country. Western Michigan gets a lot of snow in the winter, or at least it used to. We haven’t had much snow the last 2 years, but that’s not the point. Weather can make or break a weekend away, so knowing what’s going on in the area, weather wise, is really helpful.

Being an engineer and programmer I really wanted to be able to automate systems around the house and track the weather patterns over time. There are certain websites that will give you access to this data, some charge a nominal fee, others not so nominal, and others offer that data for free with limited access. Free sounded really good, especially after buying a house, but limited access wasn’t going to cut it. I wanted access to the data as often as I needed, and near real-time. Also, for a reliable system, this would require extremely reliable internet, and my internet connection at the house is anything but reliable.

This led me down a very long path to finding reliable sensors that allowed local access to the data, outside of a simple display. After a few searches on the internet I found myself at Ambient Weather. This is a great site for everything weather related, most of their offerings are around a basic weather display, but they also sell some kits that are WiFi enabled. In general the the WiFi systems use their connectivity to send data to Weather Underground, which is one of those free but limited sites I mentioned before. Wunderground is a great community of weather enthusiasts who install their own sensor arrays and push data to “the cloud” aka Wunderground’s servers. Developers can get access to this data using the Wunderground API, which I’ve used many time before on less intensive projects.

This is great, but again my access would be limited. I needed reliable real-time data if I wanted to integrate it into an automation system. I knew the sensor arrays had radios to transmit their data to the base stations, but intercepting and decoding that data was a bit beyond my skillset at the time. Although I did pick up a SDR to attempt it, with little success.

Long story short, I ended up purchasing this system WS-1001 WiFi Observer. It has a decent sensor array and is very reliable, but I was stuck with using the Wunderground API for data access. It worked great for tracking weather patterns, but the automation system would have to wait.

Fast-forward almost 3 years, I started working at NAR in the R&D Lab. We have a mission to improve quality of life for homeowners and educate our membership on the coming technology shifts in real estate. Smart Homes and home automation were on the rise, and members wanted and needed to know more about the benefits and pitfalls of a connected home. My previous work on local automation really shined when it came to the security concerns of a connected home. With little to no internet required, the attack vector was extremely small, someone would need physical access to the network to do any real damage. The search began again, with vigor, for local weather data. Luckily other people with far more skills in reverse engineering RF had been busy building software and hardware to address my concerns.

Ambient Weather had sold a device to do exactly what I needed, the Airbridge Receiver, it was out-of-stock and pretty expensive, but it actually works with the exact sensor array I have and the more expensive Davis Instruments systems. I was eventually able to track down the producer of the receiver, SmartBedded, they market the receiver as the MeteoStick. I went ahead and purchased a few sticks as well as the individual sensor arrays that I’d had great success with over the last 3 years. A few weeks later all the components had arrived, I put together the sensor array and plugged in the meteostick, and holy crap, I had real-time weather data streaming into my laptop with no internet required!

Grafana Weather Dashboard

Grafana Weather Dashboard

We’ve since gone on to build out a whole system for monitoring the health of buildings, including our own IEQ sensors as well integration with smart meters for monitoring energy consumption. We call the system Rosetta Home. I’ll be giving a talk about the system at a technical conference at the end of March. We’re also working with several non-profit organizations that are doing work with residential energy retrofits.

Chris’ Day 1 CES-capades

VW and the Coldwell Banker panel.
What do you think of this VW? I kinda like it.

Hey, are you up and looking at cool cars the day after your flight gets in at 3am? Nah. But Chris is, and he’s wasting no time with that camera. You can check out the photos as he takes them here.

faraday future
Here comes the future. It’s growling at you.

That’s it for now. We’ll keep it coming. Is there stuff you want to see? Write us at @CRTLabs with the hashtag #realtorces.

Follow the hashtag #realtorces to keep up with us. If you have things you’d like them to see or find out more about, tweet us @CRTLabs and use the hashtag. Wish Chris and Dave good luck! You can follow them on their personal twitter handles as well. Chris is @entropealab and Dave is @conroydave. Good luck! Oh yes. I would be remiss if I didn’t thank Coldwell Banker for the exhibitor passes they provided us as a sponsor of the show. Thank you to David Siroty and Athena Snow for making this happen. Follow their CEScapades here.

CRTLabs V1.0

Presenting CRT Labs v1.0. It’s been a few months in the making, but we’ve finally got the last of our furniture in.

Some of the details include;

Workbench and Hood
Workbench and Hood


Lounge and Meeting area
Lounge and Meeting area


Display Wall
Display Wall




Christmas Lights
Christmas Lights


I’ve also included a panorama of the space, it’s a pretty big image, so give it a second to load.