20 gallon fancy tailed guppy aid?

hey i have 20 gallon long fish tank with a space heater and two filters and the fish i have are ;
9 guppies and two mollies
i have 4 zebra danios but they give the impression of being to be nipping my guppies i need to know if this is aggression or are they playing pleas oblige i dont want to lose any of my guppies i would cry i love my guppies
Usually zebras don't do that, they are heavenly fish. Do they really bite guppies or are they just playing? Mine zebras don't do that with guppies, strange, I wouldn't worry going on for it unless you see that they're really aggressive

please read this. good luck
http://aquatropicalfish.com/forum/index.
Danios can definitely nip guppies, even in a larger reservoir and in school.I had this exact problem.

I moved my danios to a smaller side cistern. Everyone has been happy since.

I have a school of danios and had this issue. Some people will communicate you that adding a lot more danios and having a especially big school will make them more peaceful and get rid of the problem. I figure that's possible, but it's also possible you'll now have more fish doing impossible to tell apart thing and it will make the problem a whole lot worse.

You can make available the danios away, get a second container and move them over there and add to their school, or look at a container divider which would only be a temporary solution since you'd have a smaller nouns for them to swim and they're kinda ugly (the divider).

I now have danios within a smallish tank in a school, and guppies within my big tank with my loaches. Everybody is happy.
Answers:    Your tank is a tad overstocked. You should only have almost 9-11 fish in your 20 gallon, so either keep adjectives nine guppies only, or your danio's, mollies, and two guppies. They are probably nipping at your guppies from lack of space, zebra danio's are generally not aggressive. This could be the problem though, as your tank is overstocked.

EDIT: Your zebra danio's are schooling fish, and should be in groups of six or more. They get stressed out well, if not put in a group like this, and the nip of the guppies is probably another part of their stress.
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