Backyard Aquaponics
A place to discuss aquaponics

A week ago I'd put in a big heaped handful and the trout would jump for it and it would be gone in a few seconds , now it seems theyre not hungry

Duckpond took 20 trout , so I think Ive got about 30 - 40 left , more than enough to eat a handful of food .
water parameters are fine . topped up with bore water last week ( which I tested before hand ) , a little rain , but pH is steady at 7.5 , ammonia and nitrite at 0.25 , nitrate is 40 or so , average tank temp is 15 degrees

I added salt before the large water change , so thats dropped off . So Im thinking :

would a sudden drop in salt cause the fish to go off the food ?
would losing 20 of their mates make the scared and less hungry ? ( maybe Duckpond was lucky and got all the hungry ones and Im left with the lazy ones )

the last 2 lots of rain have had the effect of pulling the pH down a little towards 7 , but it floats between 7 & 7.5 . Plus it also makes the water slightly less clear

the only thing I can think is to add more salt again and see what happens . They are all swimming happily , no sign of disease or damage to their scales or fins

so .... does anyone know why rainbow trout would suddenly be alot less interested in food ?

http://backyardaquaponics.com/forum/viewtopic.php?f=2&t=3594
try this link Boris, dbird had similar problems but turn pump on for longer periods seemed to fix his, but maybe they just decided to have a spell from eating, but in the end they are fine

thanks Nocky

from Rupe in that thread :
"not uncommon for fish to go off the feed if there's a sudden drop in barometric pressure... like a strong cold front sweeping through...."

that would be it - raining all day today , cold as buggery

or , from OBO :
"My trout wont eat in the mornings when the pump has been off overnight. I would assume DO is too low for them first thing."

same thing happened last two mornings to me - I went out to find the venturi wasnt pumping bubbles, just water , it seems to stop pushing bubbles very early in the morning every now and then for some reason

so Im going to assume both the drop in ar pressure due to the cold front AND the lower DO in the water due to the venturi nt cranking out bubbles all night to be the cause of the lack of interest in food , and thus not freak out just yet

They take a little , say a qarter handful , but dont come back for more . They didnt eat anything yesterday afternoon cause it was overcast and the tanks in shade so they couldnt see the food

Im just trying to avoid the "wait and see" turning suddenly into the "waited and saw them die, and dont know why"

Do you only feed once a day?

I think we have the same batch of fish Boris
but mine would love to have more than I'm giving them.
I am going to say it again for those who missed it...
shell a few peas to the half spheres, or should I say open the pod and
remove the husk from a pea and see if the trout will eat the half spheres!
take more they will eat them!

Just tried feeding when there was a break in the weather - 2 in the afternoon , sun is shining into the tank

they took about half a handful again but werent interested in the rest

I'll try the shelled peas next time the weather clears

Only feed them what they'll eat Boris... give them a half handful... if they'll take a little more then fine... just don't dump in a set amount...

It'll only be wasted... and decompose... potentially compromising your water quality parameters... robbing DO... increasing ammonia....

Boris, its all to do with the movement of water in the tank - they must have water that is constantly moving, or they wont eat. Gnash and I have both experienced this.

Changing from an air pump, to a water pump splashing water fixed my feeding problems overnight. And the water stays warmer too

Yep... they like fast flowing water.... by nature...

So , having the air-pump for oxygen AND the pump for water circulation would be ideal>?

the waters moving fine - theres 2 1400LPH pumps in the 1000L tank running constantly , one with a makeshift venturi , one with a proper one , PLUS the 15 minute fill & overflow from the 550L sump
I think it was the storms that have been around , theyre eating shelled peas like mad now

I agree Boris... only feed what they'll eat though...

If you like wasting power - then yes. In 1 metre deep tanks, it takes a lot of air pressure to push the air down, this reduced my total flow of air to very little. I was using a total of 6 air outlets from a couple of air pumps, feeding 4 tanks via 13mm pipe into some pieces of weeper hose. Fish were not happy after a nighs of little water movement. Delete air pumps, run water pump, save 50 watts of power - happy fish.

If I had of had a bigger higher pressure air pump, I may not have needed to change to a water pump, but the water pump was spare - and works well.

Hi,

Just to restart this topic, I've had troubles with my trout feeding.
Do you guys suggest having strong water movement for them to get them to feed again?

Cheers

Well you first have to give us some details of your system, how many trout, water parameters etc.

water parameters are as you expect. 0 Ammonia and Nitrites
Water temp is now under 20's and above 15
25 trout aroun 10-15cm in length
1100ltr pond
with 1000ltr of grow bed
constant flow
smallish pump being used for venturi but isn't creating a large amount of water flow