Science project for my 8 year old

[DREW]

Well, my son has a science project due in a week. With me & the wife working we haven't really had much time to work on it. Thought maybe he could think of an idea to get started but no, more interested in video games. So this morning the wife told him he is going to do something that relates to Salinity in a salt water tank. Like why it's important in saltwater tank. & salt to water ratio to establish a livable solution. Also maybe what could happen if Sg gets too high or to low, we'll get that info mainly from books & the web.

Just wondering if anyone here has done anything like this that could offer some suggestions. He is 8 years old & in 3rd grade , so it doesn't have to be really complex. Any links on water chemistry would be helpful. Going to the book store today to find something.
not sure if this is the right place to post this, sorry if not.
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Thanks for the help
DREW

 

[OrionGirl]

It's a good topic, but I would narrow it down significantly. I'd suggest going with something direct, and easy to gather the data. For example: How evaporation affects salinity of salt water. Then, setup a 5 gallon tank with 4 gallons of water mixed to a specific salinity, mark the water level. Mark the water level and measure the SG at the same time each day for the next 5 days, and record the readings, and take a pic of the tank with the marks. This gives good data to create a graph, is repeatable, and shouldn't take too much time. The other changes that could be tracked are alkalinity, and pH, but I'd probably keep it simpler.

Then, the info on what happens can be sort of filler, why it's important, etc.

 

[DREW]

Thanks Oriongirl, that helps a great deal. my 29 gal tank is evap'd down a little. Maybe i can just fill that back up with fresh water & start from there, Or should I go ahead & do a water change now, or wait till after project ?, since it is due for a water change.

thaks for being so helpful
DREW

 

[OrionGirl]

I would top it off, and do the water change. The salinity changes can be significant in smaller tanks, and will impact any livestock in the tank. The water change is to help remove wastes and replenish trace elements--neither of which will impact the 'experiment'. I would not use your main tank for this, simply because the changes to be monitored will negatively effect the animals in the tank.