Curious, have you ever raised any of these critters? If so then you know what I stated to be true. Do otherwise at your own peril. That article you propose as a factual source, is not factual, it is one tank among many- based upon opinion- do the same study in 500 individual aquariums- you'll then see what is actually tried and true. But believe what you want. Again. do as you like at your own (and the clams peril). To the O/P, listen to what I tell you- it is correct. Better safe then sorry.