Report "I have a pond which holds roughly 4000 litres. I bought the laguna pressure-flo 5000 to deal with the algae. The pond has been in existence for roughly 8 years and so algae has been building up for that period of time. My QUESTION: How long should it take the laguna 5000 to clear the algae from the pond. I backwash the unit everyday. Thankd davie email address [email protected]"