Hi Skittler,
Sorry, i've just seen this.
This is just the way I do things (with a bit of advice from Seb at Pro shrimp thrown in).
Because I have a fairly heavily stocked shrimpery (I think – it now has 10 micro rasboras in there as well), I change 30% per week. Seb thinks 20% is OK for a low level of stocking, but I'm sure other shrimp owners could advise on this.
I used to just do changes with a jug, but I've now started using a syphon. I use a syphon that I think is originally meant for a bio orb. It has a blue squeezy bit that you use to start the syphoning off. It also has a screw on attachment on the bottom which has a plastic grid. I take this off when syphoning my shrimpery, which leaves a very wide opening so that if shrimp are sucked up, they won't be damaged.
I syphon the water into a white bucket because the shrimp are easier to see on a white background. Shrimp do get sucked up, but they're easy to see and I just fish them out using my special shrimp net and pop them back into the shrimpery (it's worth getting one of the special nets that retains its shape because the shrimp are less likely to get damaged. I just put the net into the tank and they swim out of it very calmly).
Seb (pro shrimp) says that shrimp can take fairly large water changes (though I have seen other threads on different forums that suggest that this isn't so good for them) as long as you don't dump large quantities of water in suddenly. So, unlike my fish tank, I dribble the changed, dechlorinated, water in very slowly – it does take a while. Then I put some Bacter AE in (supposed to help the biofilm, but don't know if it's strictly necessary. Other people use beta glucans at a water change, and I've just got some but haven't tried it yet).
All my fish and shrimp appear to be thriving, so I hope I'm doing the right thing! Others will, no doubt do things differently, and probably better, so don't take this as gospel.
Hope it gives you some ideas though.
Diz1