So Basically I'm wanting to do a fishless cycle and things typically are tight at the moment! I can't find a reasonable sized bottle of ammonia! Not really wanting a large bottle and having to pay costs for p&p!! But my friend has a couple of goldfish so was thinking of asking her if I could place my filter in there! How long would It have to remain in her tank! And also although her fish seem healthy enough is there any way disease etc could be introduced into my tank or would this only be present if the fish were I'll? Wanting to do this right first time no set backs like!!! Thanks!!!