You haven't told us how long the trough is, or how deep the water is in it. If it's full to the rim ... 2-ft deep ... then there's 44.88 gallons for every foot of the trough's length.
700 gallons
It depends on what type of water heater do you have. For a gas-heater, 75 gallons is considered large. For the electric heater, 120 gallons is considered large.
A trough is something that contains food or water. A small animal might be fed from a bowl; a large animal needs a bigger food container. That's a trough. A visual: you know how in movies set in the American West, after a fight, somebody ends up in the water container the horses were drinking out of? That's a water trough.
The question is not very specific. There are many kinds of water tankers. A water tanker truck, of the largest 18 wheeler kind, can carry about 30 tons of water. Which is about 8000 gallons.
At least 6 gallons!
It depends on the context. For a single person's daily use, 15 gallons is a lot of water. However, compared to industrial or agricultural water usage, 15 gallons may not be considered a large amount.
Helps if you bury it in the ground for a few months first, so the insects can work on it for a while. I use a large stock pot and 5-6 gallons of water when I'm boiling shark jaws.
There was a deep trough where the lake water emptied into the river.Scientists have been looking for rare fish in the deep underwater trough.
60 billion gallons
Well we always bring our horses to the water trough and pick the water up to the horses mouth, and most of the time after that they all just come and drink from the trough. Hope that helps =)
With 20,000 gallons of water, you could fill a swimming pool, water a large garden or agricultural crop, provide drinking water for a small community for a short period of time, or support industrial processes that require a large amount of water.