I recently moved my male guppies over to my 60L tank as the first step in trying to keep my guppy sexes seperate, however I've noticed they are now spending quite a bit of time sitting on the bottom of the tank. Their bodies are upright, but their tails lay flat on the gravel.
The tank they came from has an external filter with a spray bar outlet so has little circular current, whereas the 60L tank they are now in has an internal filter that circulates the water at quite a rate.
Is it normal for guppies to rest like this?
These males seem to have tiny bodies compared to their tails, so I'm wondering if they are just tired. I have turned the internal filter flowrate right down now to see if that helps but I'm not sure what else it could be. All water stats are fine, the shrimp in the tank seem fine, but the guppies are seemingly listless.
I also did a water change at the weekend, and I think it may have been too cold for them, (20L of cold water into a 60L tank. It dropped the temp from about 22 down to about 18 deg. C when I did it, and I noticed then that the guppies seemed to decend to the floor and 'shiver'. As quickly as the kettle would boil I removed 10L of tank water, and replaced it with 10L of boiled water mixed with cold to recover the tank temperature, and the guppies did seem to improve.
I've attached a picture of the guppies, (appologies for the blurriness, my camera doesn't do well with movement & no flash), you can see one laid on the gravel bottom left of the picture, (ok you may need to squint a bit!)