Ok I decided to have a shuffle round and a clear out, and in doing so move my frontosa into two 4x4x2ft and make two groups as I have two males and thought I'd give them a chance to have a harem each.
I've been trying to breed these fish for several months, without success now, although the females will hold, they swallow the eggs after about five days.
Anyway I started moving them over into the new home, when I suddenly notices what looked like dirt on the sand substrate. To my shock and delight these turned out to be 30 free swimming frontosa fry!!!! So I'm very HAPPY!
Will post pics when I get the chance.
Just thought I'd share my news.