How to Clean a Pool Filter Tank

You know your pool filter tank needs cleaning because your pool is no longer looking sparkling blue, but more a greenish "On Golden Pond" type color. Take a deep breath and grab some wrenches, because this sucker is a big, heavy thing that takes some wrestling to take apart. After you have done it once, though, and you've seen how it all works, the next time won't be as difficult. Think how happy you'll be when you see your pool pressure gage 10 lbs. per square inch lower, and the pool nice and crystal clear again. Here are some helpful tips to tidying up your pool system.

Difficulty: Moderate

Instructions

1. Turn off the pool filter.

2. Open the backwash lever to the unlock position. This will allow water to drain out of the tank. This takes a few minutes of steady water coming out. Also open the air valve on the top of the tank to let out trapped air, so it doesn't pop the tank off when you're trying to unscrew the heavy top. Tighten the air valve again.

3. Use a wrench to unscrew the metal belt that is holding the tank together in the middle. The nut you will be twisting is right next to a corkscrew spring that will loosen as you untwist the nut. It's slow going, but keep at it. When it's loose enough, remove the nut and look at the corkscrew to make sure you remember how to put it back into the nut when you're done. Set the nut aside. Remove the belt and lay it on ground at the base of the tank.

4. Twist the top half of the tank to loosen it. You may have to stick a screwdriver between the two halves to let some air in to help you get the top half off. It is heavy and cumbersome to take off. Remove and place to the side. You will see the filter panels arranged in a tall, circular cylinder, like a heavy hula skirt from hell. You want to lift the entire piece up and out of the filter tank. This will be heavy because the filter panels are coated with Diatomaceous Earth (DE) and green goo from your pool.

5. Have a hose handy to spray off the whole cylinder and filter panels from the dirty DE and algae that has collected. The cleaner you spray these panels, the better. Return the whole cylinder back into the pool filter tank, keeping in mind that there is only one way it will fit in. Lube your "o" ring that is laying in the groove of the bottom half of your filter tank to make it easier to seal. Lift the huge tank cover and replace it onto the tank, tightening the belt and putting the nut back on to the corkscrew spring. Tighten until the corkscrew coils are touching. It will feel like a very long time, but you want this tight to keep air out.

6. Turn filter back on. Let the tank fill up. Add some coffee cans of DE into the pool filter, to re-coat the inside of the filter panels in the tank with DE. Your pressure gage should read much lower, meaning your tank is clean.