Syno nigrita and feather fins

[Princess]

I have a feather fin syno and a nigrita, and both are developing cloudy eyes. They're fed on Sera and King British catfish foods. One is at work in a giant tank with loads of other random fish - mainly livebearers and other bog-standard fishies. The feather fin is in my tank at home. Both are getting the cloudy eyes. We live in a hard water area and I have heard that hard water can cloud syno eyes up. Is there anything I can do to stop or reverse the cloudy eye-ness? I think the nigrita is blind already, and I don't want my feather fin to go blind too

[seds]

usually a few tank cleanings over the next few days might clear up eye cloud. I heard it can be caused by dirty water...
I am not saying you have bad water, but...
My gourami got eye cloud, but I dont know about the hard water thingy.