Are glass cats brackish, let me check..
...thats glass fish, hmm
How big is the tank? Glass cats need a fair bit of space as I recall. I think a group of pretty girls would be a lot safer on the whole, girls are a little more active, and will swim, part and reconvene as a group, and can deal with current a lot better than males since their fins are shorter.
Well if all you have in there is the glass cats then you should add a few more of them to start with. They really love to shoal together, and the more there are the better their behaviour ( and they look so much better in a big group too )
As long as the current isn't absolutely blasting round and you have some areas well planted for hiding and escaping the current if needed, then a group of 6 girls would go just fine in there with 10-12 glass cats.