You could try to gradually get them used to the sinking food. I had a similar problem with my fish that they didn't even see it!
But goldfish are digging in the gravel since that's how they naturally eat, so it might be nice allowing them to stick to their instincts like this C: Either way, your goldfish are sure to find the food even though they might not be noticing it from the start. So just feed it to them few times a week for starters and then do it gradually more until they're used to it, then you should be able to feed them with both the sinking food and the floating one (: My fish are now pretty fast with going to the sinking pellets when they notice that there's nothing by the surface And it took me just a few weeks to get them used to this.

You're welcome (: If it might help, I was feeding shelled peas to my fish in the start, they're sinking too and they're a bit bigger and easier for the fish to notice, so maybe this could also be useful to try?
Use natural, frozen peas that you thaw for a few minutes and pop them out of their shells when they're thawed (: If your fish are small it could be useful to cut the peas into some smaller pieces (:

You could probably feed them a bit of finely grated carrot.  I usually feed my fish anything we are having without seasonings.  Like today we had steamed broccoli and I fed our fish that and they enjoyed it.  Most goldfish are not picky eaters and will readily devour anything given to them.

I gave our fish thawed peas but because they almost choked the last time, ( even if I cut it as small as possible )
this time I pressed those little peas through a sieve, and our fishies ate them in no time.

By the way, Hepsiba had white poo last day, first I thought it may have been caused by Melafix, but then I seen Humphrey's poo was normal colour. Could it be absorbed eggs? They both behave normal, Hepsiba does not show any discomfort. Haven't seen her poo today.


.... so that's how we go from food to poo, lol...

I read sometime that the poo is like this, whitish and transparent (?) when the fish hasn't been eating enough recently. For instance, if their tank mate stole their food It shouldn't be dangerous though (:

So then it's nothing to worry about!

I think that's a good thing! I've seen too many people looking at fish thinking they're fine until they start floating upside-down...
It makes me kinda' sad... :C

Or get it while keeping. I can't stand people who simply don't give a crap and then flush the fish in the toilet because "it's just a fish". GAAD, as soon as I got my goldfish I bought a big book about them and started reading about all kinds of disease and feeding advice and how to care best for them and... stuff. Because I do care, and for me, my goldfish are much better than a cat! (But I do like my sister's cat)

I love fish and cats and some kind of dogs.
This reminds me, when I was a small kid, we used to have a cat and one tomcat, later we had kittens too. One of the kittens stayed with us, the others were given away to people. Anyway we also had a bowl with a couple of guppies and neon fish.
The small cat, her name was Kitty, when she was a teeny, she jumped up to the cupboard where the fishbowl was. It was so cute, she did not want to catch the fishies, but she looked at them, wanted to play from outside the bowl, lol
And when she was thirsty she drank some aquarium water, and when she was tired, she slept next to it , but never touched the fishies.
She was a special Kitty anyway, because she loved salty peanuts, chocolate, veggies cooked in soup, all those crazy things. So you can imagine that I was a crazy little girl and just out of experiment I gave her a tiny bit white bread dipped in red wine, LOL, she ate it and was tipsy... funny to experience a tipsy cat she was so cute, big eyes, wanted to keep her tail up, but couldn,t and she wanted more, well but I did not give her more.
She was always present when my mum cleaned the fishbowl, very interested in watching what was going on