When your racking, if you had any type of filtering device it would stop the siphon especially in a young wine. I am not sure what you have floating on top but if you ferment with fruit you can use a nylon bag in the primary to hold the fruit, then when you get ready you can remove it easily. After the wine has been racked once or twice you can then filter if you wish but you will need a pump to force the wine through a filter, some just choose to let the wine bulk age until it quits dropping sediment.
If something is floating on top (I'm assuming its a piece of fruit) maybe you can suck it out with a sanitized Turkey baster?
When your wine is clear, all the suspended yeast will have settled to the bottom, So every month or 2 months Check the bottom of the Carboy, if it has sediment rack it... Then check in another month or so, once it stops dropping sediment then its "Clear". If you bottle it to soon while its still dropping sediment Then you will have sediment in your bottle, which will cause off flavors in your wine, thats why you want to rack it and not leave it in the carboy to long while its dropping lees, they call the sediment lees.
Just a note, from what I have read, add camden every other racking. There is some misleading info on the net, from my research It seems some great wine makers add every other racking. Some books will say everytime you rack add camden. Good luck, hope this helps!