you can use a rasor blade to remove the algae or credit card, most pet stores sell razor blades attached to wands to help reach the depth of the tank without getting your arm soaked.
Cloudiness is a sign of one of two things a bacteria bloom, or poorly washed substrate.
So the question would be Is this tank new, did you rinse the substrate or did you just change over the substrate.
Or have you done anything to effect the bacteria of the tank (assuming its an established one) -ie. Cleaned the filter in un dechlorinated water. filled the tank up with unprepared water etc.
You can usually remove cloudiness by doing partial water changes, 20-50% at a time depending on the size of your tank. there really isnt any information about your tank that i can go by. Water stats, size how long its been set up etc?
