Backyard Aquaponics
A place to discuss aquaponics

My goldfish that I bought as feeder fish about 18 months ago to cycle my first system are now a reasonable size (probably not far from 15cm from head to the very end of tail). Their growth has been far from optimum because most of the time they had to just get the crumbs from what the perch left in terms of food.

I have 5 of them, they are all commets (pretty ordinary fish I know). They started as bronze ones (hence sold as feeder fish) but all but one is now vibrant orange with white on their tails.

I have moved the 4 gold ones to a fish tank tonight and am hoping that I have a female amongst them. The plan is to have a go at getting a batch of fry. No idea what I would do with the fish if I am successful - but should be fun. Once I've picked the sexes - may move them to one of my 200 litre round poly fingerling tanks to do the business. Will probably just try a conventional mop. Have plenty of tanks - so no probs moving the mop once eggs fertilised (or as Monya would say - sprogged on).

they certainly are nice fish. shows that almost anything will colour up given a chance.

How can you tell which are girls or boys and I do mean with fish?

Do you really mean that - or just being polite. Mr expert - do you reckon they are worht breeding or will the fact that they were bronze to begin with mean that their progeny are likely to start that way also?




Faye - Stu indicates that the males often have some sort of little white spots on the gill rakes. I'll have a closer look tomorrow - but I didn't notice anything.

I may just leave them and see what happens. If nature takes its course then hopefully I'll see who is doing what (re the fish laying and sprogging) and then be prepared for next time even if the first lot is lost.

kinda like whitehead pimples on the gills.

BTW - for all those people who ask whether goldies and silvers or jades are okay together, these fellas have been living with silvers and jades, the biggest of which I expect would be well over 600 grams. Surprisingly - even their tails seem to be in good condition. This is also a big rap for AP. No water changes but extremely healthy and conditioned fish :-)

I believe that all goldfish start out bronze/brown/dull. I suspect feeders are just those that are smaller and slower to color in any given batch.

Makes sense - thanks Janet.

Ya fish that are slow to colour up often get culled. I culled most my oranda's one year before they developed the mantle... dammit. Me mate ended up with a feeder tank with a few $50 panda's swimming around in there... 'so know ya wanna buy your feeders back eh?'

Yup in breeding season males will get the gill pimples, they are also usually longer thinner fish. Females ripe with roe can sorta be seen from above.

I have found keeping them cool then a slow warm up can trigger spawns. Best to keep male and female seperate then add to tank and watch. If they spawn cool remove parents. If not remove the male. Put him back in when you can watch again. If you leave them together they will spawn and eat eggs and you will neva know hey.
Do you have greenwater you can use for fry?

I have had a sticky at the fish today and can't see any of the pimples. Don - Stu also suggested the heating them up thing. They were pretty warm in the AP system - so I should remove the heater I put in the 50 litre aquarium (for the purpose of keeping them up to the temp they were at in the outside tank) and let them cool down, then later on down trach heat them up again I suppose.

Don't have greenwater - was going to try and make food from egg yoke. Can you talk me through how to make some green water?

Well basically you start up a pond and feed it fish food. Leave it in the sun and ya let it go pea soup green.
Quite a few ways to do it.
Without getting too sidetracked lemme give ya quick run down on old technique, but ya have raised about 10 goldy spawns so long way from being a master lol.
So first off I setup a childrens wading pool. Usually have duckweed in it. So I water change the breeder tank and dump water in childrens pond. The nitrates in old water causes pool to go green in sun. I then take replacement water out of pool and into the breeder tank. So the pond gets green thru goldfish tank water. Anyone once I spawn I remove mops (neva letting touch air!!!!!) and put in pool. Because its the same water there is no shock.
So ya thats one method. Another is a handful of dynamic lifter in a bucket and then ya strain greenwater thru muslin.
Sun and nitrates = greenwater in most cases.
Once ya got the greenwater bloom lots little critters move in to eat it and are also good food.
Big thing to watch is insect larvae (dam dragon flys) in the greenwater eating fry.
eggyolk works but dam its messy
like feeding discus beefheart = lots water changes

so you dont add the green water to a tank with free floating fry?

I'd be likely to just add it as you say Steve. I think most of us have made green water at one time or another - so there is heaps of experience here

i might even do australias first Phd in green water