Neocaradina should be fine mine are thriving at 8.2). The ability of driftwood, catapa leaves, etc depend on how hard your water is (high ph is often hard but not always). Pretty much none of the natural fixes for high ph do anything in hard water. Also, you run the risk of oh fluctuations with water changes or as your wood/leaves break down. Most likely, you’d need to go with reverse osmosis water for caradinas
That seems pretty high. But neocaridinas might be okay.
If you want to lower it naturally. Use driftwood, and/or peat dirt in a bag (let it soak in the water or put it in a hang on the back filter.) Be mindful that both these options release tannins into the water which will create a blackwater aquarium after enough time. You can sorta control this affect by taking the bag of peat out when it gets too dark, or water changes.
I have 3 tanks with shrimp sitting at pH 8.0-8.2 because of the KH buffering additives I use (crushed coral/aragonite) and they are doing great. I will say, there’s definitely a period where before the populations took off they were either slow to breed or I lost a few, but once they started reproducing they boomed.
I just found it too much work to chase pH, and my other readings were fine. GH and KH in perfect range for neocaridina.
Everyone is talking about natural options. If you really want to you can use chemical means as well. They sell PH buffer solutions which can help neutralize your PH. They also sell acidic solutions to lower your PH.
One thing is that if you use these, you need to make sure when you do water changes that you keep doing them.
If this is a new tank that you are setting up, you can also use a PH balancing substrate to help neutralize it.
Also ask whatever seller you have what PH they keep their tank at. If their shrimp are fine in a similar PH then don’t worry
Did you test right after water came out the tap? If so, let the water sit out overnight before testing. There are gases in the water that affect ph and they dissipate.
Bramandbass 
Neocaradina should be fine mine are thriving at 8.2). The ability of driftwood, catapa leaves, etc depend on how hard your water is (high ph is often hard but not always). Pretty much none of the natural fixes for high ph do anything in hard water. Also, you run the risk of oh fluctuations with water changes or as your wood/leaves break down. Most likely, you’d need to go with reverse osmosis water for caradinas
I’ve had thriving neo colonies in central Texas, where the water is basically liquid rock. (8.5-8.7)
Would catappa leaves lower it?
That seems pretty high. But neocaridinas might be okay.
If you want to lower it naturally. Use driftwood, and/or peat dirt in a bag (let it soak in the water or put it in a hang on the back filter.) Be mindful that both these options release tannins into the water which will create a blackwater aquarium after enough time. You can sorta control this affect by taking the bag of peat out when it gets too dark, or water changes.
I have 3 tanks with shrimp sitting at pH 8.0-8.2 because of the KH buffering additives I use (crushed coral/aragonite) and they are doing great. I will say, there’s definitely a period where before the populations took off they were either slow to breed or I lost a few, but once they started reproducing they boomed.
I just found it too much work to chase pH, and my other readings were fine. GH and KH in perfect range for neocaridina.
Everyone is talking about natural options. If you really want to you can use chemical means as well. They sell PH buffer solutions which can help neutralize your PH. They also sell acidic solutions to lower your PH.
One thing is that if you use these, you need to make sure when you do water changes that you keep doing them.
If this is a new tank that you are setting up, you can also use a PH balancing substrate to help neutralize it.
Also ask whatever seller you have what PH they keep their tank at. If their shrimp are fine in a similar PH then don’t worry
How big of a tank? Might be worth it to look into either a RO filter/ purchasing RO water or buying and remineralizing Distilled water
Time for some tannins
They’ll do fine. Consider drip acclimation if they’re coming from vastly different parameters.
test gh and kh. if they’re in range then it should be fine
Did you test right after water came out the tap? If so, let the water sit out overnight before testing. There are gases in the water that affect ph and they dissipate.