I'm on the edge of my seat...but still thinking that there must be some chemical reaction that yields a false positive in the test, hiding the true nitrates. Now I'm not a chemist and have no idea what might be in API's Stress Coat or the Red Sea test, but I'm sure if there was some magic elixir that removed nitrates from aquarium water it would be like a shot heard round the world. And we'd all be using it! Although I might say "seeing is believing", this one deserves a much closer look lest we believe we can simply and easily turn lead into gold.
I was going to say the exact same thing -- that I am not a chemist.
So I have no idea what's really going on here. And as I stated from the beginning I was NOT looking for a product to reduce nitrates; I was only looking for something to help my rambunctious giant half moon betta who got so excited at feeding time he jumped out of the tank. After researching the after effects of a fish jumping out of a tank I learned that their protective slime coat gets damaged and saw recommendations to use Stress Coat+ (apparently there are several different kinds of Stress Coat and the only one that's recommended was Stress Coat+). So I ran up to Petco and bought a bottle.
I then used it when doing water changes for my rose petal betta in the 5 gallon tank as well since he had a lot of torn fins. It was only after that that I "discovered" the lowered nitrates, and by deduction boiled it down to the addition of the Stress Coat+.
It's undeniable. I didn't "rig" anything. I don't have any vested interest in API. And why they don't tout this product as a nitrate reducer is beyond me. The only caveat I can think of is that, like other products that "bind" ammonia and/or nitrites, for example, there may be a 24-48 hour limit on this nitrate reduction process.
And of course there's the matter of whether or not the aloe (in the concentration used in Stress Coat+) is harmful to the fish. As far as I'm concerned, after having read everything I can get my hands on, the jury is still out. (It runs the gamut from "HELPFUL", to "NOT REALLY HELPFUL" to "POSSIBLY HARMFUL TO WATER CHEMISTRY" to "HARMFUL TO THE FISH'S GILLS". Go figure.)
Given the fact that, while it's annoying, the 5-7.5ppm nitrate level of my tap water isn't the end of the world and I would consider just going back to Seachem's Prime. Or API's Tap Water Conditioner, without the aloe. (I'm sure my half moon guy, Nessie, is out of the woods after his Houdini attempt, and Raggedy Andy, my rose petal guy, seems to be doing fine now.)
So it's an ongoing learning process. Everyone has his/her own opinions about what's best for this and for that when it comes to the hobby, and a lot of it, most notably from the manufacturers themselves, is not what it appears to be. So it's trial and error, which is risky business when dealing with living creatures for which all we want is to provide the best environment.
And if we're honest and we really boil it down to brass tacks -- we're playing God when it comes to the hobby. We're taking living creatures that live in nature in much larger homes and we cram them into glorified toilets. (Sure...we try to make them the most accommodating toilets possible, but they're still glorified toilets. And that doesn't even get into the tortuous breeding practices, especially for bettas.)
So I'm generally not too impressed with "purists" who claim this way or that way is the best/only way, because EITHER way we're manipulating variables for living beings who didn't ask to be stuck in a toilet -- whether it's a 500 gallon custom toilet or a brandy snifter. Just my 2 cents.