We have koi, tench, grass carp & 2 surgeon. We've had 1 surgeon for about 5 years and the second one is new, arrived a week ago & settled in well :)

The problem we're having is getting enough food to the sturgeon, esp. the new one. We feed floating food to the koi & carp and sinkning food for the sturgeon.
Our first sturgeon was fine on sinkers for the first 2 years and grew really well, but in that time the koi also grew & so did thier ability to eat all in sight! He then learnt to feed of the top (for the sinkers) to get a belly full, becasue as soon as the sinkers whent in the koi suck it all up!
The floating food we use is about 30% protein and allthough the first sterlet is healthy on this, it has retarded his growth . The new sturgeon will not eat floaters and is not getting much of the sinkers (thanks to the other greedy fish!), we have 42% protein sinking food for him, but he can hardly get any of it, he's only little (12 inches) and as he's new to our pond, I want him on his optimum diet to make sure he is over any stress from moving to our pond and he does need to fatten up a tad for winter, as allthough he'll eat in temps as low as 4 degrees, we limit winter feeding to stop the koi damaging thierselfs on it.
I am reluctant to get a higher protein floating food as it puts too much stress on the bio filter and we'll end up with murky water (& then I can't see how the sturgeon are doing), also that wouldn't help the new one anyway as he wont eat floaters.

The bag of sturgeon food states to 'ensure all other fish have been fed, before putting in the sturgeon food', but I don't think it's possible to fill a koi up in the summer!! The best we've managed so far is for OH to get ready to drop some sinkers in at one end of the pond, while I attract the rest & feed them at the other end (bless em, they speed accross the pond like rockets when they see you, heads out of the water, mouths going waiting for food), but it still doesn't give the sturgeon much time to eat, I've even put some sinkers in for them, but all that does is encourage them even quicker to feed of the bottom. I've tried putting lettuce in as a distraction, but they don't bother with that untill they've cleared the pond of pellets! We've even tried dangling our arms in the pond around the sturgeon and trying to frighten the koi away, but they're getting so tame they don't bother about that.

I don't want to resort to chucking in loads & loads of sinknig food and picking out any uneaten pellets, as again that will drop the water quality and give me new problems (even if the food is removed, it's very oily which will effect the water/filter), it will also be too expensive to do that.
I can't wait untill the sturgeon are big enough to bully thier way to the food like the other fish.

Any suggestions or ideas as to how I can feed the new surgeon without the koi eating it? Anything your koi go mad for that I can use to distract them from the sinkers without risking water quality/overloading the bio filter?

Are there big size differences in the fish?  Could you perhaps make a feeding container that the sturgeon can fit in to eat but the koi can't?  I saw something similar for piglets to stop the adults eating the piglet food.

Thanks for a quick repy :)
It's a good idea, something I've thought about, but the trouble is the sturgeon are long & thin and don't swim backwards very well (the koi aren't much longer than the biggest sturgeon, but they are great big fat things). If a koi/carp/tench got it self stuck in something it would back up with a bit of wiggling to get out, but the sturgeon try to turn, if they panick (which they do quite quickly if they feel stuck) they do thrash about and I'm worried about one getting stuck or doing itself damage if it were to get stuck inside something :( also the material used will have to be of such that it doesn't damage the pond liner, or any fish if they swin into it (they batter one another around at feeding/spawning time).
Ohh i do worry about my fishies!

I've been digging around on the 'net and I'm not alone with this problem, but I'm even more worried now. Thier lack of competitiveness for food can actually stop them eating they suffer from malnutrution quickly, they'll bend into a 'U' shape and die :(  BUT apparently snails are thier favourite and are recomended to tempt a sturgeon that has gone off it's food, so while I'm trying to find out a way to distract the koi, I'll invest in some water snails for the sturgeon to munch on, there are normally loads in the filter, so I'll go & have a look now :) We've always made sure there are no snails in the pond so the shells don't block the pumps, but if the stugeon will eat 'em, I'll put some in.

How about a metal cage type thing though?  So they can just pass through, no need to turn.  Means a lot of coat hangers would be getting cut up but it would work :-) Then you could sell them on ebay if it works ;-)  The ones for pigs are just bars that the piglets can slip through but the bigger ones can't.

> Then you could sell them on ebay if it works

Patent it and go on Dragons Den :-)

Sorry i've got no suggestions but good luck in your quest

> So they can just pass through, no need to turn

A sturgeon sized tunnel :) I have a plastic tunnel for my rabbit to play with, something like that but much more narrow may do the trick, the tench would still fit through, but they're not that greedy. Good idea :)

This is like my new sturgeon.

Aaaawww, cute :-)  Yep, think you've got your problem sorted now.

As a tunnel how about a piece of drainage pipe etc, comes in various diameters.
j

I think in your shoes, i would teach the sturgeon to feed from a tube that the fat koi cant get into...

If that fails then really your only option is to divide the pond so that the koi and the sturgeon are seperated (which might not be cheap given how big your pond must be if you can fit sturgeon in *jealous!*) until they are big enough to hold their own.

> I think in your shoes, i would teach the sturgeon to feed from a tube that the fat koi cant get into...
>

With a tube, it would have to have a diameter wide enough for the larger sturgeons pec fins to go through without him knocking them, which would also make it big enough for some of other fish to get in, the tench would dive in it as a hide out (they're shy things and like to hide in dark places), so  I don't think a tube will work :( BUT!!!! we have some guttering knocking around the garden, I've found some guttering that isn't rounded, it's flat at the bottom with 2 sides angled up & out (if you can understand my rubbish discription!), which means it's wide, but without the height, so the sturgeon should be able to pass through easiliy without any other fish getting in :-D Now I just need to get OH to cut some off for me.

We had some sturgeon food arrive yesterday and the new sturgeon actually cruised around the pond seeking it out :-D but at £11 per kg I don't want the koi gobbling it all up, so wee will try the gutter-tunnel today :)

>how big your pond must be if you can fit sturgeon in *jealous!*

LOL, it's not as big as those lovely display ponds at garden centres :( It's only 11ft x 7 ft, must be big enough for surgeon though as Buster 'helped' us dig it out and has proved it can easily accomodate a sleeping Mastiff taking a nap after working so hard (scrat, scrat, eat a bit of it then sleep), with room for all of us to sit in it and have a coffee break.