I don’t know what can have happened to it – haven’t seen it against the filter, but I guess it could have been eaten quickly. Sigh.
A couple of days ago I noticed one of the cloaches seemed to be, for want of a better description, be blowing bubbles. It’s very odd; there seens to be white stuff coming out of its mouth every now and then. Not sure whether or not to be worried!! And two of the SAEs were having a serious fight earlier, although they seem fine now.
Randomly Yours, Alex 
I have been keeping harlequin rasbora for over a month now and watch them daily. I love watching them swim in a group. Since it was a tank for harlequin rasbora only I wanted to keep a compatible fish and found out that betta does great as a tank mate. I read an article on a website about Betta tank mates
I found this article very helpful.
Thanks for sharing the article with us.