Over the past decade or more, I've seen numerous "before & after" feeding trials involving NLS and other brands of food. I've also ran several of my own feed trials involving sibling fish. There are a LOT of factors that are involved in these types of feed trials, and depending on the species, genetics, age, sex, water quality, stress, hierarchy within the tank, etc, and the overall "control" conditions being used for ALL of the test subjects, the results can & often will vary.
Also, the statement on the New Life website clearly emphasizes that one will only
begin to see enhancement in both color & vitality by the 10 day mark.
http://nlsfishfood.com/index.php?option=com_content&task=view&id=12&Itemid=60
Feed New Life Spectrum® fish food exclusively for 10 days.
You will begin to notice enhancement in color and vitality of your fish or we will simply refund your money. Please Note: your fish will continue to improve in color and overall health over the next 30 days.
An exclusive daily balanced Spectrum diet will help prevent lateral line disease, fin erosion in surgeonfish, and hole in the head on angelfish.
IME by 30 days, in some species the difference in color alone was night & day, in others the change in coloration was very subtle, so much so that some people might not even notice it, especially if they are looking at the fish day in & day out. The same with overall vitality in a fish, this is something that is rather difficult to gauge in many species of fish. I know that even with some of my fish, until I actually went back & viewed some of my "before" photos, I hadn't noticed some of the subtle changes in color in the fish. With video it becomes even more difficult, still images (photos) are your best bet for determining overall color changes in the fish. Take numerous before photos (under the same lighting etc), and numerous after photos, and you just might be surprised what the human eye missed the first time around.
With regards to the poster that stated that shrimp give their Red O's their color, actually genetics is what give your Red O's most of their color.
The amount of astaxanthin (the red color enhancing agent) found in krill or shrimp (including the shell) is but a tiny fraction (80-150 ppm) of what is found in micro-algae feed additives such as Haematococcus pluvialis. (15,000-40,000 ppm) But there is a fine line between
natural color enhancement, and
unnatural color enhancement, where fish that are naturally
yellow, begin to turn a very unnatural
orange. Some commercial fish foods will actually bring about those types of results, typically due to their overuse of
synthetic color enhancing agents, such as Carophyll Pink.
To a large extent this hobby is very much about visual impact. While there are those that will appreciate the behavioural characteristics of even the blandest colored fish most hobbyists want to see eye popping color, and for many hobbyists that's
all they care about.
Personally I want to see color that matches the best looking specimens in the wild, but at the same time I want to provide the most nutritionally sound diet that I can offer my fish in the hopes that they reach their maximum potential health wise as well. If I can get 10 yrs out of a fish, vs 7 yrs, that too is important to me. If I can keep a fish healthy even when under the stress of captivity, or aggression from rival tank mates, for myself that's just as important as color.
My quest in the pet food industry began approx. 30 yrs ago, with dog food, and in that area you simply don't get the same visual dynamics as you do with tropical fish. Dog owners look at digestibility first & foremost, and everything else usually follows. A dog can have a great looking coat, shiny eyes, and white teeth, but if it's scat looks like it came out of the back end of a donkey, then it's obvious that most of what's going in, is coming right back out the other end. Of course when one doesn't have a "filter" picking that waste up each day, unless you live on a large acreage it's kinda difficult to miss.
In dog food digestibility of the food is EVERYTHING, yet with fish I suspect that most freshwater hobbyists don't give it a second thought, if they see decent color, in many cases that's probably all they care about.
But ... if you keep marine fish, especially some of the more difficult to keep in captivity species, this is where foods begin to play a much larger role beyond just color. You can't simply jack up a low grade food with astaxathin, marigold meal, and spirulina, and expect that it will keep that fish thriving in captivity. It's not that simple, and with the more difficult species you best provide them with the best of the best raw ingredients, or you can kiss that $200-$300 fish good-bye.
With many marine species, it's a matter of life & death.
Unlike many freshwater species, you simply can't keep species such as Moorish Idol, Rock Beauty, or Achilles Tang on a mediocre starch laced food & keep them alive, let alone thriving, let alone colorful. So for myself, I look for the best of
both worlds, a food that will keep even the most difficult to keep species in captivity thriving in a glass cage, as well as provide great color.
IMO this is what separates a good food, from a GREAT food.
. Cant say I notice a color differnce however, but they are cons so matting colors are always coming an going.
