Breeding goldfish is actually a fair amount more difficult than most people would think. Much like us humans, Goldfish are rather particular about the conditions in which their little fishy babies will thrive.
Like women, goldfish females appreciate a date done right. They require proper mood lighting and temperature, a nice meal and a romantic environment to “get-it-on”.
To breed your fish, these natural phenomena need to be replicated in order to produce the proper conditions for healthy egg production and maturation.
To get the best chances of success for you’re goldfish breeding, improve the odds. Rather than tossing one girl and one boy fish into the tank, use a two male to one female ratio. Using six goldfish has pretty good possibilities, without overcrowding the tank. The males and females should be kept separated until spawning season, when they can all be joined in one big party.
Preparations for breeding fish should be taken approximately one year prior to spawning season. During this time, it will be your job as matchmaker to replicate the cycle in their natural environment. During the fall, water temperature should be kept cool; around 35-40 ºF and feeding should be reduced to three times per week.
Dry fish flakes should also be combined with worms (fish sized bites of course), duckweed and brine shrimp, which will help produce healthy eggs. After a couple of months (i. e. the winter), the water temperature should gradually be raised to 50-60 ºF, thus simulating the pre-spawning stage. This stage can last four to six weeks, giving you plenty of time to ever so slightly increase food rations (but not too much) and increase the temperature of the water without putting Goldie into shock.
For spawning to begin, the temperature of the water should be around 65-70 ºF. To prepare for this special occasion, a spawning mop or breeding pad should be placed on the bottom of the tank, and extra plants should be put in the aquarium. The plants act as magnets for the sticky eggs, making it easier for egg collection and relocation. Once everything is in place, reunite your goldfish buddies and let the romance begin.
After 3-6 hours, 500 to 2000 eggs will be released and (hopefully) fertilized, and then it will all be over. Infertile eggs, distinguishable by their white and hazy appearance should be removed from the tank as soon as possible, while the amber coloured fertile eggs should be moved to another tank with the same water temperature. After 3-5 days, the eggs will hatch and you will be the proud parent of many hundreds of fry!
The parenting of fry continues well after hatching, so make sure to inform yourself with information concerning feeding, bacteria control and filtration. Best of luck!
Mark Sturge is webmaster of goldfish-answers.com. A site where you can learn all about goldfish care as well as information and hints for successful goldfish breeding