Well I stupidly went and bought couple Zebra Nerite not thinking about their PH level. I drop them in my PH 7.0 tank and some in my PH 6.0 tank. They almost died from the PH 6.0 I had to immediately move to my PH 7.0 tank and luckily they recovered.
I guess Nerite is not a good choice for CRS tank. I have a minor hair algae issue in CRS tank, do you guys think Assassin or Malaysian Trumpet can do the trick in PH 6.0 tank.