The amount of DE (diatomaceous earth) needed for an 18x36 inground pool filter typically ranges from 1 to 2 pounds per square foot of the filter's surface area. To determine the exact amount, check the filter's specifications, as they often indicate the recommended DE amount. Generally, an 18x36 pool may require about 4 to 6 pounds of DE, depending on the filter model. Always consult your filter's manual for precise guidelines.
Need to rephrase question.
To calculate the linear feet of an 18x36 pool, you need to determine the perimeter. The formula for the perimeter of a rectangle is (P = 2 \times (length + width)). For an 18x36 pool, this would be (P = 2 \times (18 + 36) = 2 \times 54 = 108) linear feet. Thus, the linear feet of the pool is 108 feet.
Its more about water volume and filter area. We have a 100,000 gallon pool that uses 180 square feet of filter area - these consume 25 pounds of DE every time we backflush and recharge the filters. Assuming your pool is 5 feet deep on average you only have 3000 cubic feet of water which is about 23,000 gallons. So you would need roughly 6 or 7 pounds of DE. Of course if your pool has more water then you need more DE. Your filter manufacturers should tell you how much DE you need.
Just unscrew the filter. If you cannot remove it with your hands, it was put on too tight, which is common, as most people tighten them too much. You will need to use a good filter wrench. The type wrench you will need depends on how much room you have. Oil the gasket & Put the new filter back on and only tighten it 3/4 turn after the filter makes contact with the mounting surface. By doing this you will not need a filter wrench when removing the filter next time. 3/4 turn is plenty tight and any more is too much.Just unscrew the filter. If you cannot remove it with your hands, it was put on too tight, which is common, as most people tighten them too much. You will need to use a good filter wrench. The type wrench you will need depends on how much room you have. Oil the gasket & Put the new filter back on and only tighten it 3/4 turn after the filter makes contact with the mounting surface. By doing this you will not need a filter wrench when removing the filter next time. 3/4 turn is plenty tight and any more is too much.
I have etching in my inground concrette pool and i need to know how to fix it. the pool was made in 1973 i bought the house three years ago.
4.5 Quarts including the filter.
5.7 qts. with filter change
5 quarts with filter change
Get a new diving board. Seriously.
Most filters are carbon filters, so they won't filter out much flouride. For that, you'll need a more robust filter.
Changing the filter 3/5 gallons...
6 QTS. with a new filter.