Yes, you can use totes to hold that water, but while you are filling them, they are changing temp due to the surroundings.
Why not use a simple inexpensive flowmeter? Then you just measure the fluid temperature (easy to do) and record the water flow rate.
1 2" Female Thread 0 2 2 0 GPM 1 7 LPM Water Liquid Inline Flowmeter Rotameter | eBay
Steve