lfs didnt have any in, ordered some off ebay yesterday hopefully the will arrive today, 10 for £3.99, checked all my water stats last night
ammonia - 0
nitrites - 0
nitrates - 10
so looking good thankfully, it fell off again last night while i was home so ive put some heavy stones on the top of it to stop it floating out the water and sort of jammed the front of it against the light unit (added a bit more water than normal to bring it up) so if it does come off it shouldnt float out the water, and also used some single sided ones with a 6mm plastic pipe connection that are stuck to the back of the tank just above it again acting as a device to stop it floating out the water, seems to have worked (fingers crossed)
hopefully my new ones will arrive today and then I can put 10 onto the back of it to stop it moving again !