Cost

• Prices will vary based on size, shape, and contractor, but concrete pools are typically more expensive, ranging from $17,000 to $45,000 while fiberglass can be built for as little as $15,000. However, depending on amenities, desgin, materials and other bells-and-whistles, you can build both types of pools for over six figures.
  
  

Installation

• It is much easier to install a fiberglass pool than a concrete one. Installing a fiberglass pool takes around three to four weeks, while building a concrete pool could easily take three months.
  
  

Maintenance

• Fiberglass pools require much less work to maintain a healthy appearance than do concrete pools. Because of a porous composition, concrete pools with plaster walls retain far more dirt, microbes and organic material than fiberglass pools.
  
  

Variety

• While fiberglass pools usually must be chosen from a series of pre-designed shapes and styles that are installed as pre-fabbed shells; concrete pools can be customized completely to be whatever design the decorator desires. However, there are some fiberglass pool installation methods on the market today that don't used pre-fab shells and do allow for customization and the creation of myriad shapes and designs, much like concrete.
  
  

Considerations

• Once installed, traditional fiberglass pools (shells) should never be completely drained, especially in areas with high water tables. If the pool shell is drained, hydrostatic pressure from the surrounding ground water can force the shell right up out of the hole and cause thousands of dollars in damage to the plumbing, deck and ancillary equipment.