Backyard Aquaponics
A place to discuss aquaponics

Hi all, I have a chance to buy some left over Skretting fish feed for my trout. I thought I recalled reading something about it keeping for only so long - but can't find the source now.... So stupid question time... Lol

So does it have an expiry date as such?
If I want to keep it longer term (say 6months_12mths) should I do anything special? Like freeze it or...sealed bag or something.?

Thanks!

Will be interested to follow this thread. I've wondered the same thing.

I overordered small floating pellets for my silver perch fingerlings when I got them. But I've kept the pellets well sealed and still use them in a small garden fish pond with native eastern rainbowfish in it. The fish seem to be doing OK and the pellets look and smell OK about 20 months later.

Over time you will have a lose of vitamins in the feed and ultimately it can go rancid over a long period. Personally when I first started AP about 15 years ago I used to buy a 20kg bag and keep it outside in a bin for about 12-18 months or longer without it going rancid, fish still ate it with no problems.

Sealed up, stored in a fridge or freezer is a far better idea though..

I'm feeding the remains of my 2013 Skretting pellets to my trout ATM, I stored them in vacuum sealed bags and kept them in the dark. They still look and smell fine.

We used 7mm skrettings a couple of years ago bought repackaged in sealed bags from a reputable supplier, and although the trout ate it and grew it didn't orange up the flesh. Last year we purchased in bulk in a 20 kg bag and found that years fish flesh nice and orange. We are still feeding with that batch however we haven't been fishing yet so don't know if it is colouring them up.
So based on our experience it is my belief that the feed does degrade but am unsure of timeframe.

I've been feeding my trout on Ridley's 6mm (just mixing in ~5% of the old Skrettings 7mm in the past week), which supposedly contains 32/18 ppm Astaxanthin/Canthaxanthin, but the flesh on the 2 we had last night was quite pale, not pink at all.

Thanks for the advice everyone, much appreciated. I could probably obtain next year's feed pretty easily so had hoped it might keep. Might split the way I store it and see how I go.

well my fish are not touching feed that I had in storage for last 5+ years possibly even 10 ... and that's including fish that would normally eat anything , guess sometimes it does not pay to buy in bulk

feed still looks and smells good

If you think you might be storing the food for >6 months, I'd recommend vacuum packing the food, and freezing it. That's what I do. Oxygen and heat are the enemies of fish food - so you can extend the shelf dramatically be lowering the temp, and removing extra oxygen. I seem to recall that the first thing to degrade in fish food is Vitamin C.

Would citric acid work in the same way to destroy the food like ascorbic acid?

i ask because in my stupid head (and i think many other peoples too) the two are interchangable.

ascorbic acid - "It was originally called L-hexuronic acid, but, when it was found to have vitamin C activity in animals ("vitamin C" being defined as a vitamin activity, not then a specific substance), the suggestion was made to rename it."

Where as citric acid has no vitamin C apparently.

so is it all forms of vitamin C (considering vitamin c is an activity rather than actual substance??) that damage the food?

does it damage it by cooking the fishmeal component? (fish can be cold cooked with lime, etc)

do you have any idea what the reason is?

i ask because i was thinking of using citric acid in home made fish feed one day, which would contain no fish meal, as a preservative.

The Vitamin C doesn't degrade the food. It's just the first part of the feed to degrade.

oh ok thank you, yes Vit. C has a very short shelf life, it oxidises extremely quickly as far as i remember, best kept air tight.

I think i read your other comment totally wrong.