Fish Scraping Off Sand/shells

[Reid.]

1 or 2 of my fish are turning on their side and scraping themselves off the sand at the bottom of the tank or some of the shells i have. i also have a male molly who is just sitting at the bottom of the tank and barely moving, he does this for quite a while and then will burst into life and swim away but then go back to the same spot and do the same.

i have a 150l tank, PH 7.4, ammonia is maybe looks to be just above 0 (is showing as between 0 and 0.25 - closer to zero though - on the kit that i have), no nitrate/nitrite.

in the tank i have
3 males guppies
6 female gupies (3 are pregnant)
6 pearl danios
a pleco
a bronze algae eater
16 neon tetras
3 glowlight tetras
3 blue emperor tetras
3 silver tip tetras
2 wee rainbow things - cant mind the name lol.
2 other wee things - again cant mind the name but it'll come to me.
5 very young angels i added earlier 2day,
and a clawed dwarf frog!

is there anything i should be watching out for/doing?

 

[Gonze]

Well most fish do it ...almost all of mine do and you have a problem there is WAY to many fish in your tank. The angels will grow huge along with the pleco if it is a common one.

 

[WILDER]

Fish can flick even is the waters stats are slightly off.
I would do a water change to see if that makes a difference.

 

[Reid.]

Well most fish do it ...almost all of mine do and you have a problem there is WAY to many fish in your tank. The angels will grow huge along with the pleco if it is a common one.

i'll be setting up a 2nd tank next week, all the fish i have just now are all small (the mollies are the biggest by far) so most of the angels and a few of the others will be going into the 2nd tank soon.