I came across this food at my LFS -- they just started carrying it:
http://www.dainichi.com/goldfish_food.html

It looks pretty good -- manufactured in small batches, quality ingredients, etc. It also contains montmorillonite clay, which I assume is like koi clay. The website says the clay enhances digestion and promotes the biological filter in the tank. I bought a bag and will keep you posted on how it works. I have one fish that floats very easily. I can't feed ProGold two days in a row because he ends up belly-up for hours, so I am hoping this stuff works better.

Yeah Dainichi is kinda like Hikari and the clay helps with digestion. I bought the sinking ones but I still soaked it just to make sure. My fish went crazy for it.

Kristen, how have you liked this food? I'm needing to buy more and I can't decide between this or ProGold. I have little kids, 1" and 2" and big kids 3"+.

I have become as much a collector of goldfish food as I am a collector of goldfish! Here are my choices in order of preference:

1. New Life Spectrum Goldfish Formula -- My fish are bananas for this food; more so than others I've tried. The website (http://www.nlsfishfood.com/) makes some pretty tall claims for the food. I have been feeding it for about two weeks and have seen some improvement in my fishes' color. So far I have not seen any floaty problems with this food and I have been feeding it exclusively like the website says to do. Since I have been feeding this I have not seen any gassy poops in my tanks. If anything the poops are so dense they are hard to vacuum up with the siphon. It is slightly more expensive than ProGold but not as much as Dainichi. All my fish handle their 3 mm pellet size, but they might be too big for your smallest fish.
2. Dainichi Goldfish Color Supreme -- I like this food too, but it is at the high end price-wise (at least at my LFS). It works out to costing about 5 times more than ProGold. I like the calcium montmorillonite clay that is in this food -- it is supposed to be really good for fish and my water is low in calcium. If my floaty ryukin is overfed with this food then he will float. The website says that this food is made in small batches so it is fresh. The pellets are quite large -- I had to buy a separate small pellet formula for my Scrappy (about 1 1/2 inches).
3. Pro Gold -- I definitely like the notion of supporting a small goldfish-focused business. For this reason I buy whatever I can from Ken, including filters, UV units and bulbs, medications, etc. The problem that I have found with ProGold is that I have found that I can't feed it more than three days in a row without my ryukin floating badly. Even when I feed it along with peas, gel food, etc., there is always a lot of gassy poop in my tanks.

Thanks so much! Not just for answering the question, but giving a complete run-down on best foods.

I have one last question and that's about the color-enhancing foods. I've heard they turn the fish orange. I have a blue oranda with copper patches on her, a calico ryukin and a chocolate oranda. I don't want them turning any more orange than the little bit they are now. Do color enhancing foods always enhance the orange or is it possible to have a food that enhances the actual color of the fish, whatever color that is. If I decided I don't want to use color enhancing food, what is the best food you've come across that doesn't have color enhancers?

I think it depends on which "color enhancing" ingredients are involved.

There are foods out there (primarily from China) that contain artificial coloring agents to enhance red/orange colors in goldfish (example http://www.goldfishnet.com/FishFoodDetail.asp?i=1). You would probably want to avoid those if you are concerned about your fish becoming too orange.

Other color enhancing foods contain natural ingredients such as spirulina, krill, and shrimp. According to the Dainichi website (see the section on cichlid foods), these ingredients will enhance blue, yellow, red, and black coloration, so I would be less concerned about these ingredients disrupting your fishes' natural colors.

As you are probably aware, intensely colored fruits and vegetables are the richest source of vitamins and phytonutrients in the human diet. It is becoming very clear from research on human nutrition that whole foods contain a range of important nutrients that cannot be duplicated by a synthetic supplement. Krill is unique in that it is the only animal-based food that contains antioxidants and phytonutrients (the krill manufacture these colored nutrients in their tissues in order to protect themselves from the intense sun in the Antarctic ocean in the same way that tomatoes make lycopene to protect themselves from the sun). Krill oil is a rich ruby-red color, so krill-based foods are both color enhancing and health-enhancing for our fish. Color-enhancing considerations aside, because we want to offer our fish the equivalent of a human diet made up of intensely-color fruits and vegetables and healthy protein sources, I would avoid a fish food that does not contain ingredients such as krill or spirulina.

The only "trouble" that I have had with color enhancing foods is with my lemonhead oranda Betsy. When I purchased her about five months ago she was completely white, without the slightest yellow cast to even her wen. Over the months she has developed light orange blotches on her belly, her wen has become bright yellow, and now her fins are becoming yellow as well. Given another few months, I think that she will become completely "lemon" and will be unique and gorgeous. During this same time, she has grown dramatically, has healed beautifully from the effects of living a long time at the LFS (missing scales and torn fins), and has become the happiest, most outgoing fish in my tank. Given all this, I am not concerned that she is no longer snow white.

I will be curious to see what happens to my new short tail ryukin Millie (so named for her vermillion fins and tail set against her bright white body). The red/white contrast on her is striking and I would like to maintain it if possible. I will let you know how things come out with her!

Sorry for the long reply -- hope the information is helpful!

P.S. I also wanted to add that my calico telescope Winston has been eating a color-enhancing diet (Dainichi and New Life Spectrum) for about four weeks now, and shows no sign of losing his crisp blacks and whites so far.

Perfect! Just what I wanted to know! And, yeah, superb nutrition and growth enhancers are the most important to me. 'Specially for my teeny, tiny Toby. And, although Jackson, my ryukin, is still is too new to decide whether he is prone to float, in one month's time, he hasn't so far and I want to keep it that way. And a nice, solid poop is always a wonderful present! So, I'm thinking of going with the New Life Spectrum Goldfish Formula and I'll just have to break it up slightly for Toby. My big pigs are not above scrounging at the bottom for small pieces. And I bought some Spirulina flakes, so it's good to know that that will also enhance the natural colors. What an ignorant soul I would be without Kokos.....