My levels were over 2000ppm, which is enough to cause drowsiness in humans. I found out after getting a CO2 meter (Aranet4), although this is not an endorsement for that brand in particular. However, I do that knowing the levels of CO2 in your house is worthwhile. Once I took actions to reduce my CO2 levels, pH in my aquarium (a number I have been struggling with) steadily began increasing by the day. See the graphs and images below.
Before I got the meter, pH had ranged from 7.4 to 7.8. After I got the meter, I began keeping CO2 below 1000ppm by just opening a window during the day. Now it ranges from 7.6 to 8.0.
Here's a picture of the meter, this is what it looks like when I have the window open and two people are home.
I probably should have suspected this before I got the meter, but I had assumed that AC in my building (quite powerful) would circulate fresh air from outside. If it does, it certainly isn't enough.
Before I got the meter, pH had ranged from 7.4 to 7.8. After I got the meter, I began keeping CO2 below 1000ppm by just opening a window during the day. Now it ranges from 7.6 to 8.0.
Here's a picture of the meter, this is what it looks like when I have the window open and two people are home.
I probably should have suspected this before I got the meter, but I had assumed that AC in my building (quite powerful) would circulate fresh air from outside. If it does, it certainly isn't enough.