Backyard Aquaponics
A place to discuss aquaponics

I'm trying to calculate how many grams per week of food a perch would require to reach a plate size of 500grams. I have a large worm farm that i'm planning to expand to feed my fish with, and if i know how much the fish will eat (which seem oddly hard to find) i will know if my worm farm will be able to cope.

Just to clarify Timmy.... are worms the only thing you are planning to feed your Silver Perch?

Not completely, i also plan to setup bug attracting lights around the base of my pond, in summer it should pull in a hefty amount of moths etc.

Timmy, maybe read this thread for some info.....

http://backyardaquaponics.com/forum/vie ... sc&start=0

Somewhere on the forum is a FCR diagram.... food conversion ratio for different species....

But I'd think a 2:1 ratio would probably be a fair starting point to aim for ...

i.e for every 2gms of feed you'll acheive 1gm of fish weight gain.... but I'd need to find the diagram to confirm things..... suspect that would probably be a maximium conversion rate.

I'll also try and find another thread... I'm sure someone stated/linked to an article that stated feeding Silver Perch solely on worms would lead to low growth rates and health deficiencies...

Worms, bugs, insects etc are useful for supplementary feeding I believe....

The pellets are "high" protein and acheive a reasonable FCR.... whereas I think the worms don't convert very well at all.

quoted feed conversion ratios are of dry food.
i guess worms are 80% water .20% dry matter.
thus dry pellets will look much better on paper.
cheers

It would seem buying fish food would get expensive with large amounts of fish?
worm farm definately won't cut it. I've got a pretty healthy worm farm, i could produce ten's of kilo's , but if that ratio of 2:1 is correct, taking 100 fish to plate size could use 100+ kgs' of worms at the very least.
It's odd you say feeding on moths and bugs along leads to deficency's i would have through a moth would be packed full of protien. I'm going to stick a light outside in a trap and see how many grams of moth i can catch in one night. here in perth in the summer a fly trap would catch like 1 kg a day :/

Silver Perch are fed 3% of their weight on a daily basis to get an FCR of 1.6 to 2:1 (that is dry weight/pellets of ~35% protein) anything better than 1.6 needs optimum conditions (water quality and temperature).

Bugs and moths are a nice apetiser but will not provide sufficient food for many fish (maybe 1 or 2 of the quickest)

Tim regarding cost of food, i think it was monya that just grew and ate over $1000 worth of barra. I'm pretty sure he would have spent maybe 10% that on the food

ok so the feed isn't too expensive, i guess you buy in bulk. I'm just tight is all, i look for ways to cut costs when i can

Nothing wrong with that Timmy, if you've got the worms on hand, then substituting one or two feeds a week is still a saving

There's a whole thread here on the forum about raising Black soldier Flies to larvae stage as a secondary food source....

And another discussion thread about using Lupins as a feed source.