hi last night i noticed a long white stringy-like thing coming from the bottom of one of my clowns (i have 2). i did a 50% water change yesterday, so im not sure if thats just a coincidence or not. this morning the 'string' has disappeared. anything to be worried about? what the heck was it? anybody seen this happpen before? i read a few other posts here, but havnt really got a strait answer. other than that, my fish are fine, all water paramenters are good as well.