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Target Input:
We are determining the parameters of the plant that we have, and then the basics of the filter design, such as number of filters, backwash time, and the amount of bed expansion.
Condition Input:
These are where the parameters of the construction materials are entered (ex. Media and pipes). The design is for a sand filter resting on about half as much gravel.

Calculations:
Filter Calculations: First we determine the size of the filter and head loss in normal filtration. Then we use two approachs to find the area of the clear well . The first is based upon conventional knowledge that the back wash velocity needs to be 10 times the filter velocity. From there we know  that the space between the top of the filter bed and the bottom of the clear well is linked directly to the amount of headloss between those two points (headloss from the pipe, elbows, expansion and contraction, expansion of the bed). To do this, we used information from Okun  and the "Minor Losses in Pipes" Manual.

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