MY aquarium is 225 gallons and the phospahates were 0.01 before i accidently dosed 6 tablespoons of Monosodium phosphate ... i way overdosed my aquarium with phosphate and checked with Hanna, water is blue and reads .90 and flashes after 3 minutes.... I have used a bottle of phospahate RX and 24 hrs later it still reads .90 and is blue and still flashing... i am about to do a 50% water change... hope my LPS and fish don't all die on me...