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Use Your Smartphone As A PAR Meter With The Photone App

Updated: Oct 15, 2023

Ok, its not often that we get really excited about something, but we are SUPER excited about this new app. Here is why...


PAR is extremely important when designing a planted tank planted tanks. PAR stands for photosynthetic active radiation. Its how much ration the plants is receiving for growth. Think of it like the gas pedal for plant growth. High PARs mean faster growth whereas lower PAR0s mean slower growth. In the past the only way to measure PAR has been through REALLY expensive PAR meters, upwards of $200-$300. But not any more! Yaaaaaay!


There has been the release of a new app called Photone. It turns your smartphone into a PAR meter. As of September 2023, its free for Android users, and locked on iPhones for $6. But all you need to do is install the app, open it up and you have an instant PAR meter! This amazing for the hobby. So of course we needed to test all of our lights!


While this app is in its infancy, it is quite accurate. We reached out to Photone to ask them about the accuracy and they sent us a link to their findings which we will put at the bottom with the rest of our sources. Here is what the article says...

"As can be seen (below), the deviation to the Apogee Quantum PAR Sensor generally lies within a few percent. In our test, the worst case error compared to the $500 Apogee sensor lies at 7.7% with the median being 2.2% more than the Apogee sensor’s measurement. As the Apogee sensor itself has a specified accuracy of ±5% in air, we consider the deviation of our app negligibly small."

I told Photone that there was some community pushback saying these were not accurate as app in the past maybe we not so. And this is what they say...

"I (Photone) assume that the mixed feedback you're getting stems from Android users, where our current measurement accuracy is inferior to the iOS version. That's also why the app is still in a free public Beta phase for Android users, and we're heavily working on improving our Android measurement accuracy. It's been a multi-year research & development project but we intend to finally release the new Android version in the coming months"

So hopefully here within the next few months the app will be out of Beta and more accurate for us Android users. Until then your accuracy may vary.


So what do these PAR values mean? Where should your tank's PAR be? I would suggest NOT going over 80-85PAR on a non-CO2 injected tank. And when you have a CO2 injected tank, you can push PAR levels WELL into the 200s+.

We tested both of our our tanks by removing the light from the tank, so we didn't have to put our phones underwater, and measuring the PAR by moving our smart phone to 3 different heights.

1) At the water level

2) midway down the tank

3) At the top of the substrate

In physics, water and air are both considered fluids, and light passes through them the same. The only variation would be caustic refraction, but that would cause highs and lows, still giving us a medial par rating.

And this is what we got. Our Tropica grow out tank (WaterBox 30g) has a Chihiros WRGB II Pro 90 on it.

Our nano tank (Fzone NovaClear 2g) has an ONF Flat Nano+ on it for lighting.

If you want to see the app in action, we used it in our latest video which was a review on the ONF Flat Nano+. You can watch the video below:


To give you a little context on the tanks above. Both are CO2 injected down one full PH point prior to the lights turning on, and both are being fertilized with the ASG Feralization Kit. In order to achieve these PAR levels in a tank, we must remove the carbon limitation by injecting CO2. Once we do that, PAR levels can be pushed through the roof. Not only does plant growth go crazy, coloration does as well. Look at the Ludwigia Super Reds in this picture! I just don't want everything thinking they can blast their lights at 200+ PAR without CO2 injection and good fertilization. When plants are blasted with high PAR, we need to make sure they have enough carbon and nutrients to grow, otherwise we're going to definitely see algae.

Furthermore, this article address PAR and not PUR, photosynthetic usable radiation. Just because a light produces a good amount of PAR doesn't mean its in a spectrum in which our plants can use for photosynthesis. If you'd like to learn more about how to dial in your lights spectrum when you have (W)RGB control, check out our article named "Dialing In Your Programmable LED Aquarium Light". And if you have a Fluval 3.0, check out our article named "What Settings Should I Use For A Fluval 3.0 Light". And of course you can reach out to us directly in the comments section of this post, down at the bottom, if you have more questions.


Photone Website:

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