me and my grandma have a single 30-40 gallon tank. we have two males and four females. is it possible to get them to breed in a single tank? what can we do to help basically 'induce' breeding?

Guppies will breed anytime anywhere. All you have to do is sit back and wait. They will have babies about every 4 weeks with around 20-60 young depending on the age of the female. The rule is 1 male to 2 females, so you have the perfect situation. You will need a breeder though to protect the young from the mother because she will eat them after they are born.

well we've had them for about 3 weeks and nothing has happened.

They probably keep having babies and they get eanten and you never see it.

Get a fish breeder, when they get fat put them in it.

AND WHATLAH! Instant guppies!

the females don't even get fat. their gravid spots don't get bigger or darker. i don't know what to do.

Yes. The parents and other fish will eat them if they can. The hard part of making them breed is getting them to stop. As for why they aren't making babies is that you just gotta have patience. It'll happen, unless something is wrong with the tank or fish.

well yesterday i looked in the tank... and two of the females were considerably larger than the other two females. i dontk now if it was because they were pregnant or if they are eating more. i looked for the 'gravid sopt' but have no clue what it looks like. people say its a black dot, but i dont see one on any of the females.