Kizza, you must be either about 7 hours later than or 17 hours earlier than those of us here on the eastern coast of the United States. Your profile doesn't indicate your location, but I assumed that you were somewhere with an English accent which is closer to the Queen's english than the United States as you used the term "mum" instead of "mom" that is frequently used here in the U.S. Given the time difference I would guess that you might be somewhere on the east coast of the Australian continent, New South Wales, Victoria, or Tasmania perhaps? You don't have to tell us your exact location because as a parent of a teen I understand the importance of not sharing your personal information on the Internet.
I'm sure there are several of us here on the backyardchickens forum that would be interested in following your project, giving advice, and hearing the progress as you and your brother attempt this first egg incubation. Just realize that most of the active posters to this forum are in the U.S. or perhaps Canada and that if we don't respond to you immediately during your afternoon or evening hours, it is because we may be sleeping due to the time difference.
If you get a chance to take and post a picture of the potential parent chickens of your eggs (roosters and hens) we would love to see what breed of chicken you might be hatching.
Some more advice. You will want to take care in how many days over which you spread the addition of new eggs to the incubator. The last 3 to 4 days of incubation (18-21) and right after chicks hatch you will want to keep the incubator closed and humid to help the chicks in breaking our of their shells. If you keep adding eggs into the same incubator, then you may end up with some chicks hatching on day 21 and then more hatching several days later. If you end up having to open the incubator up to keep removing the hatched chicks, it may affect the success of hatching for the later eggs.
I would recommend that you keep eggs within 3 days of each other in the same incubator. You can also save up eggs for 3 or 4 days and then add them all at once to a second incubator. That way all of the eggs are added at the same time and the hatch dates will by synchronized for all of the eggs in a single incubator.
Your second incubator looks like an improved version. You guys are doing great. If you still can't quite get the 37.5 Celsius in the plastic incubator, then wrapping the incubator with a towel or old blanket could help hold in a little more heat. Actually anything for insulation of the container would help keep temperatures even across the bottom of the incubator where the eggs are located. As long as you are measuring the 37.5 Celsius air temperature at the level and location of the eggs you will be right on with the temperature.
You should keep notes on your date, time, temperature measurements, and turning of the eggs. Also to make keeping up with the turning easier, mark one side of each egg with an "X" and the other with a "O" and write down which side is up each time you turn the eggs.
I have a teenage daughter and I know how important encouragement and support is to young people. When I was a child, my parents always encouraged me to try things and told me that I could succeed at most anything I really wanted to do. Now that I'm a grown up (at least in age), I realize that they were great parents who really believed in me and helped me succeed in life. It's always easy to think about how something won't work out, but it takes vision, hope, and effort to figure out how to make it work. You seem to have all of these elements already, so I am hopeful that you will be successfull in hatching some chicks.
If this hatch doesn't turn out, I'm sure that you can find more eggs somewhere, review your incubation notes, refine your incubator setup, or do what's required to finally succeed. We are all pulling for you!
