Maintenance of a fiberglass pool is similar to the maintenance for all pools: Keep the chemistry in balance, the surface and bottom clean and the water filtered. There are, however, a few maintenance items unique to fiberglass. Some of these items are an advantage, while others can create extra work.
Advantages of Fiberglass Pool Maintenace
The gel coat that forms the surface of a fiberglass pool is neutral, so it won't react with pool chemicals. This usually results in the pool using less chemicals than a plaster pool. Also, because the surface is sealed and smooth, algae cannot get a foothold to grow into the surface as it can on plaster pool walls. This makes it much easier to get rid of algae if it should begin to grow in the pool.
Problems with Fiberglass Pool Maintenance
The gel coat is less durable than pool tile, so the exposed areas above the water line can be a problem to maintain. Never brush the wall at the waterline with an abrasive brush or an abrasive cleaner. It will leave permanent scratch marks. Instead, use a soft pad and a degreasing agent, such as Simple Green, to remove any deposits of oils, lotions or debris that stick to the surface.
The sun can also dull and damage the exposed gel coat over time. To protect this exposed area, apply a heavy-duty automotive wax and buff the surface with a soft rag. Be careful not to bang the gel coat surface with hard or sharp objects. It will crack if subjected to a hard impact. This won't cause leaks because the gel coat is only a surface coating, but it will leave visible marks which will have to be sanded down and recoated to remove.
Avoid Draining a Fiberglass Pool
Fiberglass pools are installed in one piece like a large boat in the ground. Draining the pool without the proper precautions can cause the fiberglass shell to pop out of the ground or break apart. In areas where there is a high water table, this is a particular problem. If you need to replace the water in a fiberglass pool, the best way to do it is to drain no more than a fourth of the volume out at a time, then replace it with fresh water. Continue this procedure until you've turned the entire volume of the pool over and testing indicates the new water is within acceptable total alkalinity and total dissolved solid limits.