Equipments:

Tank (LxDxH): 50 x 18 x 13 inch (50.6gUS)
Filters: Marineland Penguin 200B, Marineland Emperor 280

6 x Zebra Danio (Danio rerio)
2 x Sailfin Molly (Poecilia latipinna)
2 x Balloon Molly (Poecilia latipinna hybrid)
8 x Guppy (Poecilia reticulata)
3 x Swordtail (Xiphophorus hellerii)

Suggestion: If you want to keep more than 1 Sailfin Molly, minimum recommend male to female ratio is 1:2 (M:F). You will be less likely to experience problem if you get even more females.
Suggestion: If you want to keep more than 1 Balloon Molly, minimum recommend male to female ratio is 1:2 (M:F). You will be less likely to experience problem if you get even more females.
Suggestion: Minimum recommend male to female ratio for Guppy is 1:2 (M:F). You will less likely to experience problem if you get even more females.

Recommended temperature range: 20 - 24 C. [Display in Farenheit]
Recommended pH range: 6 - 7.8.
Recommended hardness range: 5 - 15 dH.

Your aquarium filtration capacity is satisfactory.

Your aquarium filtration capacity for above selected species is 114%.
Recommended water change schedule: 35% per week.
Your aquarium stocking level is 73%

Ya oughta go with the 1:2 male to female ratio or with all females as far as the livebearers are concerned. I prefer a 1:3 ratio. Male livebearers can and will harass a female to exhaustion and death.

Beware of wild-caught P. latipinna: they are often captured from coastal regions in brackish water and won't make the transition to captivity well without similar conditions. If you are just getting the fish from your LFS, that shouldn't be a concern as the fish they get in are probably captive-bred, but it is something to keep in mind.

Provide plenty of plants (live or plastic) for cover and I think yer looking pretty good!

WYite

Thanks I have a few more questions.

1-Is my filtration good enough or sould I add another one just cause?

2-So I should add more femles, is 1:4 okay? Is their a limit on how much females to put?

3-how much plants is two much? I have fake plants because live ones are hard to take care of. I have about 2-20in,2-16in,1-12in and 1-in plants.

4-Is it bad to add more danio? Because I love how they swim in groups

5-What other fish swim in groups?

1-Is my filtration good enough or sould I add another one just cause? Plenty of filtration...you dont want a lot of current with those fish.

2-So I should add more femles, is 1:4 okay? Is their a limit on how much females to put? 1:4 is fine the more females the better.

3-how much plants is two much? I have fake plants because live ones are hard to take care of. I have about 2-20in,2-16in,1-12in and 1-in plants. You cant have too many plants.

4-Is it bad to add more danio? Because I love how they swim in groups. They do best in large groups...I like to put schooling groups together in groups of 8 to 10 or more...I would go with 10.

5-What other fish swim in groups? There are many schooling groups...It could take hours to list them all, I would research what you like and look for schooling groups.

Thanks for the info. What fish would you recommend I should put in?