Is this co2 detector ok?

[Alazo1]

I just bought a co2 detector.

The lowest number that this one detects is 400ppm. It constantly reads 400ppm. I was wondering if the unit may be defective. I do live alone and there's probably minimal co2 in my home. If I breathe into the unit several times it will raise the numbers significantly then go back down to 400ppm.

The reason for getting a meter is to see a baseline to see if I need either a co2 scrubber or feeding the airline tubing from my skimmer to the outside.

Incidentally, my ph readings are actually pretty good (8.15 - 8.25). I'd like a small bump to bring it to 8.3 - 8.4.

thanks,
Albert

 

[14 foot reef]

I just bought a co2 detector.

The lowest number that this one detects is 400ppm. It constantly reads 400ppm. I was wondering if the unit may be defective. I do live alone and there's probably minimal co2 in my home. If I breathe into the unit several times it will raise the numbers significantly then go back down to 400ppm.

The reason for getting a meter is to see a baseline to see if I need either a co2 scrubber or feeding the airline tubing from my skimmer to the outside.

Incidentally, my ph readings are actually pretty good (8.15 - 8.25). I'd like a small bump to bring it to 8.3 - 8.4.

thanks,
Albert

not kidding, just breath into it, if it works it should register higher from your exhale

 

[Alazo1]

So it appears that the unit I bought is fine. The meter does not measure below 400ppm. I think I will keep the unit. At least now I know that any ph issues are not related to high levels of co2. So no need to add another layer of complexity to my tank.

Why doesn't my CO2 reading go below 400ppm?​

The minimum level of CO2 that exists in the Earth’s atmosphere is slightly above 400ppm. This is the observed outside value of CO2. (Source: https://www.scientificamerican.com/...sses-the-400-ppm-threshold-maybe-permanently/).
Our CO2 sensor assumes 400ppm to be the lowest background level as that's the outdoor CO2 baseline level. Humans inside building tends to be the major source of CO2. When a building is unoccupied for 4 to 8 hours, CO2 levels tends to drop to outside background levels.

 

[Randy Holmes-Farley Verified Community Expert]

I just bought a co2 detector.

The lowest number that this one detects is 400ppm. It constantly reads 400ppm. I was wondering if the unit may be defective. I do live alone and there's probably minimal co2 in my home. If I breathe into the unit several times it will raise the numbers significantly then go back down to 400ppm.

The reason for getting a meter is to see a baseline to see if I need either a co2 scrubber or feeding the airline tubing from my skimmer to the outside.

Incidentally, my ph readings are actually pretty good (8.15 - 8.25). I'd like a small bump to bring it to 8.3 - 8.4.

thanks,
Albert

It should not ever read less than 400 ppm, unless you do something very unusual to reduce the normal level of CO2 in the air, which is around 400 ppm.

 

[BanZI29]

I am having the same issue. I just bought a CO2 meter yesterday. I wish I would have seen this one. I like the tracking and phone connection it has

 

[jda]

You don't need to be able to send people to mars with this so they are fine for what we need them for. Mine seems to always be around 412ppm at the lowest. What is important is that if you reach 700 or 800 then you know that you have high levels.

I have kinda been having fun with mine. 425 in room and go for a 35-40 minute jog on the treadmill and the room co2 is up to 600, then back down to 425 a few hours later. Bedroom after sleeping can get over 500 with two of us in a large room without the attic fan on. 15 people over for a party and room never got above 425 with the back door open.

We take this and a CO meter on vacation with us now. Hotel room was almost 1000 co2 and our airbnb was over 1000 as well, so we opened windows and got them down. I have never seen any co.

If your home air is around 400 and your tank has a good skimmer and plenty of surface agitation, then the pH should be near the high part of the range if you alk is above 6 unless you are adding something acidic. Check your pH meter/probe/whatever first.

 

[BanZI29]

The fact that we do keep our house closed up most of the summer, I'm gonna bet the CO2 is really high.
the meter should be there when I get home.

 

[besskurz]

I was trying to figure out what co2 meter to buy as well.

Lots of ppl complain about how unreliable most or them are and you have to recalibrate them very often.
Among several reviews I read, i found out these two.
Any of you had experience with the Aranet or inkbird

https://a.co/d/9isxGGS

https://a.co/d/fm5NFUz

 

[jda]

Those both look really good. The one that I have was only like $50 and it is accurate and came with a cord and wall brick - it is not as complex as those. It goes down to 400ish when I go outside and went up to about 1800 when we had a crew over on Monday.

 

[Alazo1]

Mine did fine for about 2 months then the reading is all over the place. The warranty was out on it so I could not get a return. JUnk!

 

[InvaderJim]

Those both look really good. The one that I have was only like $50 and it is accurate and came with a cord and wall brick - it is not as complex as those. It goes down to 400ish when I go outside and went up to about 1800 when we had a crew over on Monday.

Do you have a link to the one you use? Ones on amazon have reviews all over the place.

 

[jda]

The one that I have is no longer listed. It looks like this:

 

[RelaxingWithTheReef]

I like the INKBIRD https://a.co/d/9isxGGS

Many home CO2 meters that you would find on places like Amazon typically have internal CO2 sensor modules that have a feature called "Automatic Background Calibration algorithm (ABC)" enabled.

CO2 Sensor ABC Calibration Explained

The ABC - Automatic Background Calibration algorithm allows the CO2 sensor to dynamically shift its CO2 reading by a constant.

www.co2meter.com

The algorithm will constantly calibrate the sensor over many days by using the lowest CO2 reading to establish a new 400ppm reference level. These sensors are primarily designed for large HVAC systems where the buildings are programmed to periodically purge with fresh air, or unoccupied at night or over the weekend, causing the CO2 levels to periodically return to outside are levels.

This becomes problematic when this mode is enabled, and the unit runs inside a typical household where the CO2 level typically never returns to outside air levels. The result is a reading around 400 ppm after a few day of running. Putting the unit outside for a couple hours every few days should keep these units in proper calibration. But who wants to do that?! I'm not sure what some of these manufacturers were thinking... Yes, there will be some small long term drift with ABC turned off, but I don't think it's a concern for us reefers or the typical household user.

The INKBIRD unit does not appear to have ABC mode enabled, and I have found it provides a good stable long term reading over time.

 

[besskurz]

I like the INKBIRD https://a.co/d/9isxGGS

Many home CO2 meters that you would find on places like Amazon typically have internal CO2 sensor modules that have a feature called "Automatic Background Calibration algorithm (ABC)" enabled.

CO2 Sensor ABC Calibration Explained

The ABC - Automatic Background Calibration algorithm allows the CO2 sensor to dynamically shift its CO2 reading by a constant.

www.co2meter.com

The algorithm will constantly calibrate the sensor over many days by using the lowest CO2 reading to establish a new 400ppm reference level. These sensors are primarily designed for large HVAC systems where the buildings are programmed to periodically purge with fresh air, or unoccupied at night or over the weekend, causing the CO2 levels to periodically return to outside are levels.

This becomes problematic when this mode is enabled, and the unit runs inside a typical household where the CO2 level typically never returns to outside air levels. The result is a reading around 400 ppm after a few day of running. Putting the unit outside for a couple hours every few days should keep these units in proper calibration. But who wants to do that?! I'm not sure what some of these manufacturers were thinking... Yes, there will be some small long term drift with ABC turned off, but I don't think it's a concern for us reefers or the typical household user.

The INKBIRD unit does not appear to have ABC mode enabled, and I have found it provides a good stable long term reading over time.

I bought the inkbird, let's see how it goes in the next days. It should arrive soon. I will post updates.

As a matter of fact, I confirmed that I have high co2 concentration in my apartment regardless. Specially in my tank due to the lid for holding evaporation. I did the tests recommended by Randy.

It will be surely useful, but I'm now am more concerned with the air quality in general in my place. I read that high co2 may cause headaches and make you sleep bad. Perhaps I found the reason of tireness and headaches.

 

[RelaxingWithTheReef]

My home does not breath very well, and the CO2 was typically over 1,000ppm in the summer. Not good for the reef, and not good for me Unfortunately, its not that easy to control when you are running heat or AC. I also found the vent for the gas heat was installed reversed. Instead of jetting the exhaust away from the house, it was directing the exhaust against the side of the house. They didn't seal the pipes coming out of the house, so the exhaust was coming right into the house through the gaps! When the heat kicked on, the CO2 level went crazy!
I use a CO2 controller with a window exhaust fan to ventilate the house but also not waste too much heat or AC. It works really well for me.

 

[RelaxingWithTheReef]

CO2 Controller Carbon Dioxide Controller​

DANOPLUS KB0297 in case the link did not post properly.

 

[Miami Reef]

My CO2 meter is coming tonight.

 

[ZaneTer]

The linked Amazon products are generally quite useless…they estimate a CO2 based upon a measurement of VOCs in the air.

In short they guess a CO2 value.

If you want an accurate reading the meter MUST come with a NDIR (non-dispersive infra red) sensor that genuinely measures CO2 regardless of VOC concentrations.
They do tend to be a bit more expensive though but units like the in bird CO2 controller come with them.

I am sorry to say that the small palm sized desktop units are a waste of money.

A final alternative would be to build your own unit with an Arduino and a NDIR sensor.

 

[RelaxingWithTheReef]

The linked Amazon products are generally quite useless…they estimate a CO2 based upon a measurement of VOCs in the air.

In short they guess a CO2 value.

If you want an accurate reading the meter MUST come with a NDIR (non-dispersive infra red) sensor that genuinely measures CO2 regardless of VOC concentrations.
They do tend to be a bit more expensive though but units like the in bird CO2 controller come with them.

I am sorry to say that the small palm sized desktop units are a waste of money.

A final alternative would be to build your own unit with an Arduino and a NDIR sensor.

Yes! I remember viewing a couple YouTube videos of people disassembling or testing CO2 monitors, and exposing the fraud. The people designing and marketing this garbage belong in jail!

In the past I purchased the AiRead M3, and Brwissen A18 from Amazon. The AiRead M3 has a good quality Amphenol IR sensor, something like the T6793-5K. The Brwissen also has an equivalent sensor. Unfortunately they both do not hold calibration in my home due to “ABC” being enabled in their software. Not fraud, but certainly a design blunder.

The M3 is a nice handheld device, and I still use it. Just have to run it outside for a couple hours every so often so it maintains calibration. The A18 has additional issues with crazy VOC and HCHO readings. I would avoid that one.

 

[mook1178]

CO2meter.com

If you are technically inclined, these are good meters that I used in my Masters research. Get the K30 and you can turn the ABC program off and set your own calibration with programming.

As far as indoor readings. It is winter time in the NH. Therefore extremely low levels of photosynthesis. I am in a city setting and the readings I get from the atmosphere outside my building using a LI7815 for work are ~450 ppm. There is no way you are lower than that inside in the winter time.

ABC calibration as stated throws the cheap Amazon sensors off.