Hola badflash!
I don't think you can generalize all species of shrimp like that.
Yes you can with dwarf shrimp. You'll find out soon enough.
The people I know that have the most success with CRS are mostly using CO2.
That's because they don't know any better. The people "you know" usually come from a planted tank background and add the shrimp later on keeping their original setup. As for CRS...they are having "dumb luck" that actually one of the components they are using for their planted tank setup happens to be very helpful in keeping the water parameters as close to perfect as possible (That component is not CO2.). These guys are following a formula like a machine without really knowing what that formula does and why it works. They don't even know what part of this formula actually "works" and what part doesn't. (Hence the dumb luck part). That is in no way an indication of advanced shrimp keeping/fish keeping/aquarium keeping. That's why you can read about total beginners who follow this "formula" and start breeding CRS from the get go.
Can the shrimp live at "normal levels" of CO2 injections? Sure, most of them. Will they feel happy? Well, why don't we inject your living room, bedroom, kitchen etc...i.e. your whole dwelling with CO2 and see how you feel? Will you live? Sure, because we live under higher than normal CO2 levels indoors already due to our own CO2 exhalation, but we do open up the windows once in a while to let in "fresh air" (What a concept!

). The shrimp, unfortunately don't have the window option. Bottom line is that the "people you know" are raising CRS *despite* CO2 and their lack of knowledge, *not because of* CO2 and expert knowledge.
I also don't think there is only 1 right way to raise shrimp.
Yes, there is ONLY one way and that is MY WAY!
I have been running an experiment for several months now with cherry shrimp. Two 10 gallon tanks have the same substrate and filtration systems. Same amount and frequency of water changes, same photo-period, same temperature, same amount and type of feeding.
Believe it or not, that still does not make them the same. Shrimp seem to depend heavily on how the microflora and microfauna develops. And those little buggers develop differently in every tank....unless you stop tinkering.
One has no plants, just leaves. The other is heavily planted with Java Fern and Najas guadalupensis. Shrimp flourish in both tanks. I even (last week) removed 2/3's of the Najas and saw no ill effects.
Nobody claimed that Java Fern takes over the tank and outcompetes microorganisms for nutrients (and light). Take out the java fern and just leave in the Najas to take over most of the tank. Your results might just be different. Plus, I am talking about extreme situations over a long period of time here. I was harvesting pounds of Najas out of my tanks every week while my shrimp populations were exploding at the same time (sounds familiar?). Najas will only grow like that if it gets enough nutrients, i.e. lots of shrimp feeding and/or fertilizer. The right things have to come together for explosive growth. And even then it takes about half a year or more for the microorganisms to actually starve to death. THEN, when you remove the Najas, you will basically end up with an uncycled tank.
Does this HAVE to happen every time you throw Najas in your tank? No. But I warn people of the possibility. It can happen and it would not be surprising if if did happen. You can do something risky for a long time, but the chances of something going wrong are still very high, no matter how long you have been successful with it. That's like the guy who has been sticking his head down a crocodile's throat for years and was fine. But the years of good luck did not diminish the probability that some day the croc will chomp down...and it did one day. Do you want to take the risk? Go ahead and be my guest. But don't say you have not been warned.
My point is that you need to tinker until you find something that works for you.
And my point is that there are ways and methods that work for *all* dwarf shrimp everywhere, which takes out the "tinkering" and guessing out of the game. Otherwise you'll be tinkering forever and, if you're lucky, you'll find the right solution. I'll either write an article about "the method" soon or you will just have to wait until my book comes out. I've been giving more than enough hints on the forum so far, but, of course, I can't force people to actually pick up on them.
This is a new hobby and we are all finding our way.
Of course some ways come out of experience and have been tested and proven and some ways come from pure speculation or something close to it. I have actually found *my way.* I have shared my knowledge along the way on this website, both successes and failures. Of course there are always things that can be improved upon, but those will be nuances more or less. The hobby is newer to some than for others. For me, with the amount of hours that I spent over the years experimenting, observing, breeding, going over literally hundreds (thousands?) of scientific articles the hobby is definitely not new anymore. But yes...the hobby as a whole is generally still new compared to others. But we've come a long way in a very, very short amount of time.
Mustafa's advice is always good and you can't go wrong with it, but it isn't the only thing that works. It is a great place to start.
Not a bad place to end either if you actually understand the advice and follow it. Everyone is free to do what they want and we all still learn from each other, BUT...there aren't a million "individual ways" to keep and breed shrimp. There are "perfect conditions", which is what we are all (hopefully) trying to achieve and then there is everything else. Hence, by the nature of things, if everyone actually tried to reach those "perfect conditions" (i.e. the "holy grail" of shrimp keeping), then everyone should, sooner or later, end up at the same place with more or less the same methods (give or take some details of course). There won't be a million "individual ways" because people tinkered around and "found their way." That is logically not cohesive. I could have written my book years ago, but being the "perfectionist" I am, I wanted to make sure that I find/develop "the way" first and introduce it as a "complete method" to the hobby in my book. You guys have been witness to the development process over the years here as I have shared a great deal of it (including the failures) in this forum and in my articles (whereas everyone else in the world is trying to be as secretive as possible). If I thought that shrimp keeping comes down to everyone finding their individual way, then why would I bother writing a book? The goal should be to give everyone a method that will work right away (if understood and followed of course) without tinkering ad nauseum. This is not a method to "start with" or a "beginners' method" but it's "
the method" no matter at what level you are in the shrimp hobby.
The important thing is to lose a fish or plant mind-set.
Actually, a lot of the things in the shrimp world would work for fish, too. As for plants, it all depends on how crazy you are about trying to keep bog plants permanently under water and how happy you are that you have to harvest pounds of plants out of your tank every week due to your high tech lighting/CO2 equipment and your fertilizer regimen. If you are more into natural planted tanks without fertilizer and high tech and more or less true aquatic plants, then you can transfer the "shrimp methods" to those tanks, too.