No, that packet of flakes will not last forever!
Once opened, any commercial fish food( pellets, flakes, freeze-dried etc) should b discarded within 3 mths.....I've explored all me friend's tanks, and always find 'old' food lying around...i'm sure most or us r guilty of this.
over time, some vitamins, pigments n other compounds r likely to b deficient in the product due to reaction with moisture, air, light etc. If fed solely as the main diet, it can predispose your fish to various health problems even with perfect water parameters.
what pisses me off is LFS selling 'home-made' packets of flakes or pellets in re-sealable transparent plastic bags. There is no expirary date, and the food has already been 'tampered' with.
another problem is expired products...it's just not right to see these up for sale.
anyway, i guess we should always
1) check the expirary date
2) pick the smallest or smaller sized product if possible( avoid getting a big tub for a cheaper price...u r likely to exceed the recommended 3 mth use-by date)
3) always check that the seal has not been broken. it's happened to me once..damn it...
4) stick to the 3 mth rule
5) feed a varied diet. use a variety of products...there is no testing standard with regards to fish foods...claims that the product is 'fully balanced etc' might not always b accurate. i guess there is safety going for more expensive and popular brands..
any other tips to share?