Hi I would like some male and female guppies as I would like to see them breed
Would it be ok if I had 5-6 neons and 3 female guppies and 2 male guppies?
If you wanted to get males and females, I'd recommend just 3 females and 1 male. You don't want to get too many males and not many females in a small space, because the males may fight and the females will get very stressed out having the males follow them all the time.
You said you wanted to see them breed. Do you have a plan for fry? Some (If not most) will probably get eaten, by the Tetras and the parents but you need to plan for babies just in case. You may have 50 babies in a couple months. Guppies can produce large amounts of fry and frequently. So you need to plan how you are going to raise them, and where you are going to put them or take them when they grow up. I would personally say wait until you have a bigger tank to get Guppies, and then breed them. For now, I'd get all males. Just my opinion though.
As for Mollies and salt - It really depends on how they were raised. Some Mollies are raised in pure freshwater, in which case they will be fine in that for life, but a little salt is okay, sometimes good. Some are raised in some salt, in which case they will do best in some salt. Some are raised full-blown brackish, and in that case it's not that good for them to be in full freshwater, like any brackish fish. So it basically comes down to how they were raised, along with other things like pH and hardness. You can't really say they need salt or they don't, because it varies by fish.
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Anyway, just wanted to add that...I also agree they won't fit in your tank, rdoherty. Sorry!