Sleeping Fish

I've been in the room with the tank at different times during the night, and it seems my guppy never stops moving. Is this normal?

The otos lay side by side on a short sword leaf, the brochis sleeps with the ADFs in my fake hollow tree stump (when they are sleeping, though both the brochis and the ADFs are pretty active at night).

The snail cruises around a lot, but likes to sleep on the inside wall of the tree stump.

It just worries me that it seems the guppy never stops moving.
 
all 25 of my rummys sleep at the bottom and so do the 6 pearl danios... I was freaked out the first time I saw them sleeping..I thought they were all sick and expected a tank full of dead fish in the morning.. was very relieved they were flying about when I got up...
 
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