If you have a pool you already know that eventually, you will have to replace the sand in the filter. It is very important when adding sand to make sure none goes into the lateral pipes. You must simultaneously hold the pipe in the center of the opening and pour in sand from a 50 pound bag! Cardboard protectors are provided with new units, but you wont have one if you are rebuilding the filter! Here is a quick method to produce a cardboard template to center the pipe and keep the sand out of the laterals. This could be made at home, But I made it at TechShop! http://www.TechShop.ws
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Step 1: Mark the Cardboard
I started by measuring the opening of my pool filter top. It was 8 inches.
I marked a center point on a piece of cardboard.
I then marked 4 inches on each side of the center, repeating until I had a pretty decent circle.
Step 2: Measure the Pipe and Mark
I measured the pipe. This is how large the cap must be.
I transferred the measurement to the circle and drew horizontal lines to the outer edge.
I then drew the vertical lines. This box is now the size of the cap.
Step 3: Cut, Fold, and Tape
Measure 1/2 inch inside the circle that marks the diameter of the filter. This is our inside diameter. This will be what we cut away to allow sand in while preserving the outside to make sure we have the pipe centered.
Cut the arc's for the inside diameter and cut the strait side up to the cap box.
Cut the tips off the arc as shown so you can fold them together.
Tape the box as shown.
Step 4: Cut Away the Excess
Cut away the excess as shown. The inner diameter can be rough, but take care to cut the outside diameter. This is used to align the pipe.
The tabs assist in alignment and provide something for the tape to attach to.
Step 5: Align and Tape
Fill the sand filter with water per the manufacturers instructions.
Place the lateral pipe in the filter and expand the laterals.
Place the cap over the laterals vertical pipe and tape down the guide.
Fill the filter with pool filter sand (not play sand).
Step 6: Profit!
Here it is, a full sand filter! Not the pipe is perfectly aligned and sand free!