you'll only need 1 good does of bacteria really to get you started, If amyw2008 can get to "Quedgeley" be on your door step at Cheltenham
you'll only need a piece of pad not an entire 1, cut/tear a bit off depending what the material is, and replace it with a new bit, a 1 inch cube is good enough just depends on the ratio of your filter material and other tank decor harboring bacteria to bio load of the tank.( and do it wet dont pull it out the tank put it in a jar or sealed bag with tank water just to keep it submerged, another theory is to keep it in the dark) I want to perform some tests to get some evidence but i'm still waiting on new filters in the christmas post.
its just a kick start, think of it as if you had a piece of material holding a couple of thousand/million bacteria doubling in 12-24 hours! its a great boost,
If the bacteria doubled every 24hrs
starting with 1 could build to
1 *2 *2 *2 *2 *2 *2 *2 = 128 bacteria in a week
starting with 20000 could build to
20000 *2 *2 *2 *2 *2 *2 *2 = 2.5 million bacteria in a week
and imagine what difference another day would make! another 128 or another 2.5 million!
anyway it also seems to be a good way to accelerate the Nitrobacter as you'll be introducing this bacteria too and soon as nitrite is available it can start to be used up instead of growing 1 bacteria then waiting for Nitrobacter to start its cycle to build up in numbers.
hope all goes well.
Rich