IMHO 10 ppm nitrate is fine for CRS. I had some survive and breed in a tank with fish where the nitrate level was 80 ppm+. The shrimplet survival was pretty low though, although I suspect the fish had something to do with it.
So does this apply to planted tanks?
It's not "ideal" for planted tanks period.
There's some trade off and the issue becomes one of risk, not what is ideal since ideally, we would not keep them at all, because aquarist are the no# killers of livestock in aquariums.
Can you even measure zero ppm down to say 0.01ppm?
That's not zero, but a test kit will read as such.
But is there any real risk associated with say 10ppm of NO3?
Got any evidence for it? If not, you cannot suggest or say less is better, because there is no significant difference and no risk between the two ppm's.
So is it really better?
You have not demonstrated it nor have we learned anything about the culture of the shrimp or their environment ranges.
For all of you folks claiming zero is better, what reference controls have you used, if any and what test methods have you used and frequency to measure NO3's?
Or is it just speculation, wishful thinking, "less must be better"?????????????
I gotta ask, because it sounds like lots of guessing and no real evidence.
If it is as you claim, "better", please quantify this somehow, someway in terms of growth rates, brood production, some measurable quantity.
If there is no difference in these and no evidence there is any difference in risk, then why say it is better?
This type of thinking/advice offers little informative knowledge or gain.