Backyard Aquaponics
A place to discuss aquaponics

The amount of protein in bulk flakes is not much less than commercial feed. Where people have had deaths in goldies I would put down to constipation (or off food).

I'm sorry for this basic question (I'm a noobie! ), but could you please explain why it's not good to feed aquaculture pellets to goldfish?

Thanks!

Not really true... most goldfish feeds are 28-32% protein...

Some Silver Perch feed formulations might be as low as 35-38% protein... but trout/barra feeds are more likely to be 40-45% protein....

Constipation can be cause.. especially if the pellet size is a bit big.... as goldfish have a short intestinal tract... and basically can't process the pellet in the time it takes to pass through the intestine...

Most other problems are more likely to be related to renal failure...

Jubilee, I hear what others are saying about this and I can't dispute the plausibility of their comments. What I have found in my own experience with comets and common Goldfish, ie single lobed caudal fin and standard body shape Goldfish (not fantails, veiltails, black moors, orandas, ranchu, bubble-eyes, celestials, etc) is that they grow quickly and well when fed a diet that includes high protein aquaculture fish feed.

I recently found four Goldfish living quite happily amongst a large Rainbow Trout population and they have received no food other than Skrettings Spectra Trout feed, along with whatever they have been able to scrounge off the bottom and walls of the tank. These fish had grown from a small size, ~4cm Standard Length (SL), to breeding size, ~8cm SL in the space of about 11 weeks. I know they were breeding size because it was their spawning antics that brought their presence in the trout tank to my attention.

It may be that these Goldfish have been surviving on nutrient rich trout waste rather than trout feed, since it seems unlikely that they could successfully compete with the trout at dinner time. I think it also unlikely that the trout shared with the Goldfish many of the insects lured to the tank by the bug zapper but, nevertheless, the Goldies have grown amazingly quickly compared to their siblings on a more conventional, balanced diet in a nearby pond.

This is not my only experience of Goldfish happily consuming commercial aquaculture feeds but it is the only experience I have where the Goldfish have been fed nothing else to supplement the high protein feed they received.

Fish lengths explained

Rupert

I have shifted from 32% flakes to 38% floating pellets. Goldfish do not have a short intestinal tract, it is fairly long, what they do not have is a stomach (with its ability to break down food). They also have a very narrowing gut near the anus, which is why when fed inappropriately they are subject to food impaction or constipation.
To be on the safe side I am presoaking the pellets before feeding.
I would think renal failure would be more to do with the type of protein rather than the quantity.