Well,

a fun, challenging fish i think is to breed are betta's.
Its fun to breed them, yet challenging enough. Guppies are too easy, many people have them breed without even knowin it.
Cichlids are fun to breed too!

What about breeding angel-fish?

ive bred goldfish before (fancy)

hum....

are they hard to breed?

not really you gotta cull alot thou convict cichlids and oscars or fairly easy to breed too

not hard to cull if you got lionfish

Im thinking about breeding corn-snakes

FW fish arn't good for saltwater fish i usally freeze them in tubware its very humane

How did ya breed the goldfish? Was it in a pond, or tank??? I would like to try bettas sometime too, AND angels-but i think my first prodject is gonna be kribs

4 50 gallon indoor rubmade type tubs

Ok,

kribs need some good amount of space for breeding i heard.

nah a 30 gallon is good for a pair

would my 30 gal be big enough to grow the babies out in too? , and would I need to remove the parents at any certain time, or leave them in with the babies the whole time?

Kribs are cave only spawners and will not spawn out in the open like other cichlids. Clay flower pots and PVC pipes make good caves for them to spawn in. They are very easy to breed. The female is usually first to start courting the male. She will show her colors and give vertical displays for the male. Once the pair has formed they will choose a spot to spawn and clean out the cave (flowerpot/pvc pipe etc.) and the female will deposit anywhere from 50-300 eggs, and the male will follow up and fertilize them. The female and male take turns guarding the eggs while the other goes out in search of food. Typical of other cichlids as well, they give a vertical display to signal shift change. The eggs hatch around 3 day's later sometimes longer, and the wigglers are transferred to a pit or other areas by the mouths of the parents. After about 5-10 more days the fry become free swimming, and begin to feed on organic matter, crushed flake or baby brine shrimp. Remove the fry after they are around .5" and not too soon, because if you remove them to early the male make beat on the female to the point of death because he will want to spawn again and she may not be physically ready

id suggest getting 10 gallon as a fry grow up tank

i have

33g africans
mbuna and such

10g i have a community tank with
tetras hatchets and guppys

90g i have
2 oscars, frontosa, baby africans, electric blue, green sevrum, blue acara, <<(all under 4") 3 synos, 4 rafials and a pleco

yes it will be fine to do that.

25gal L
guppys 1male 3 females 1 large female fry
mollies 1 male dalmatiom sailfin
1 male ballon
2 female dalmation
2 female black
1 red& purple betta just in tank 1 week
dwarf gourami
10gal
Kitty lionhead
5gal firebird red betta large
2 half gal betta tanks
1 half gal with 5 guppy fry that saved