Just realized that I since I put in Big Bertha and the two GF last week the pest snails have disappeared.
There were usually around 10 -15 tiny ones on the glass each day and suddenly, nothing! Are the fish eating them? Surely not the Brigs?

I'd bet my money on the fish.

You don't say...... I guess it kinda makes sense seeing as my Ranchu nearly eats my hand off whenever I put it it the tank. I've been keeping them on short rations due to constipation and new set-up so they'd probably eat each other at this point

Thanks for the AL's Online link - did you see my reply to you on the 'salting' thread?

I noticed at Petsmart their tanks have been very infested with little tiny snails and they will put one goldfish,usually an oranda, in each tank. The goldfish has the job of munching on snails throughout the day! Little pigs!
I never knew this! Would explain why I have not been able to add a wonderful snail to my goldfish tank. So I have ended up with a snail tank.

How funny!
I hadn't realised how voracious they are - even Big Bertha who's about 2" hides all day incase they nip her tentacles. What greedy little things they are!