Its a 2 foot 60 litre tank.
Erm its a Community tank 2 Silver Sharks (used to be 3), 3 Harlequian rasbora, 3 Emerald eye rasbora, 5 neon tetra, 3 glowlight tetra, 3 Cherry barbs.
And soon to be a Pleco one this problem is sorted!
The water stats were all good from the Tetra Test kits i used...