hello,brand new to the forum,so hello!. just came back from a week away to the uk(l live in sw france),only to find the person who house sat for us has been over enthusiastic whith the anti algae liquid,resulting in that every time the pump runs,a large amount of foam covers the surface of the water.ive tried runnng the pump for 48 hours,backwashed many times,tried scooping the froth off wth a fine net,all to no avail!.panic,as we have paying guests arriving this week in our rental gite-HELP! any ideas how to get rid of this foam!