Sticklebacks are one of the easiest fish to breed if you just know how. Because of where they come from, they are a temperature driven breeder. Meaning that a large dip up and down on the temperature scale will cause a spawning behavior. Mason was correct about the plants, fine leaved ones are required here. The most needed items for them are small clay pots and various caves to breed it. They require soft well oxygenated water for most of the year at a relatively normal temp...around room temp. To get them to breed they need conditioning with live foods, then the temperature of the tank must be dropped down to as close to freezing as possible for a couple of weeks. Then gradually raise the temp back up and it should kick them into spawn mode. This can be a bit tricky if you dont have a chiller. I used to do this in a ten gallon with constant ice cubes. I caution you to practise just how many ice cubes to add, and monitor the temp fluctuations over night, the amount the cubes burn off etc. Depending on which stickle back you have, if the conditions are met, you will see the males change colour. The three spine stickleback will turn a bright red. The ten spined turns black i believe ( only ever kept the three spined personally). There is possibly other ways to breed these, this has always worked for me though. Great little fishes, i dont know why more ppl don't keep these? Good luck