Backyard Aquaponics
A place to discuss aquaponics

In case you use Skretting fish feed and are not aware, the Classic FF series of feed is no longer available.

Classic was primarily used for Australian native fish such as Barramundi and Silver Perch, and was the cheapest feed in the Skretting range.

The Nova FF series is the obvious replacement but, due to it being a higher energy feed, the recommendation is to feed 10-15% less. It is available in all the same pellet sizes as Classic, as well as a smaller 3mm pellet.

Yeah I had heard that.
Nova is the recommended pellet for Barra but the protein content is too high for Silvers. I will be looking at other options.

Perhaps you could outline the effect of feeding a protein content that is too high Gav...

I thought you used Ridley's, Gav?

I would like to hear more about this, too. I have seen several mentions on this forum about Goldfish bloating or dying after being fed high protein feed, however, I have heard of commercial Goldfish growers using Skrettings Nova. Wouldn't it just be a matter of feeding less of it, perhaps with some low protein supplementation, eg roughage?

My knowledge comes from reading the results of the feed trials performed by Dr Stuart Rowland, and with him having over 33yrs of experimenting with aust native fish I am prepared to take his word for it.
His tests in the 1990's suggest that Silvers need a 35% protein content in the diet as recommended for most omnivorous fish. In further experiments he says that "the best protein contents for Silver Perch are 24.7% - 30.1%". He also states "Diets with excess protein and energy are unnecessarily costly and may cause problems such as high levels of body fat, liver dysfunction and poor health in Silver Perch".



Usually have 3 different brands on hand at any time Charlie

Agreed.. I wouldn't question Dr Rowlands research either....

Just wanted people to be aware of why a feed too high in protein wasn't beneficial... and could be harmful...

You see the same thing manifested when people feed aquaculture pellets.. to goldfish...

Goldfish are even worse with their digestive system. Although I do give them pellets (they are cheaper than flakes ) I soak them in warm water for at least 1/2 hour before feeding and not every day. They also get duckweed, spinach and peas and algae off the sides of the pond.

Yes but lets be realistic about this. I have seen many incredibly obese trout on this forum from people seriously overfeeding their trout "the correct protein feed".

We have fed the same skretting pellets to all our koi and goldfish for many years, without any problems at all, the same with the silver perch...

Yep... you can get away with it... most times.... if you adjust your feed rate accordingly...

And the incredibly obese trout you sometimes see posted... are almost certainly due to over-feeding... but probably also in combination with low flow circulation...

Correct feed protein for the species... combined with correct feed rates and water circulation... is just more cost affective... and will produce better quality, healthier fish...

Yes, obviously.... Must be why your trout pictures always look so healthy...

True, but from what I see the average person doing aquaponics tends to feed their fish more than you do at the shop. By feeding less you can get away with the higher protein diet without any issues. At the end of the day the fish you keep at the shop are mainly there for display purposes (and to keep the plants happy) where as the majority of people doing aquaponics at home want to get there fish up to edible size as soon as they can.
Lower protein pellets use less fish meal so are also cheaper to produce so should therefore be cheaper to buy, ie the Skretting Classic sold for aroud $6 a bag cheaper than their Nova product. Prices for fish meal and fish oils are increasing as Peru & Chilie (the major fish meal producers) are reducing their catch of small pelagic fish every year.

Actually our fish tend to get lots of feed.. Staff wandering around with buckets of feed throwing it to the fish to show customers the fish feeding, and it happens all day long for 6 days a week. We tend to have to go around at the end of the day and scoop up feed out of the tanks.

Edit - but we do stock lower numbers.

Well there you go - feed them less and supplement with roughage!

I have thousands of Goldfish and feed them whatever comes to hand including flakes, those red and green prills, Skrettings pellets, slices of bread (multigrain or wholemeal, of course), occasional roadkill, etc with no filtration, no aeration, no bloating and no deaths.

Well, lets put it this way then. The average trout that I see coming out of home aquaponics systems tends to be a lot larger than the ones I see in your shop tanks and thats not including the obese ones that some tend to produce!