Swimming Pool Blog
by Rob Cox May 17, 2013
How to Restore a Neglected Pool
Pools that are unattended, without chemicals, circulation and cleaning, don't last long. Within weeks, they become green, and within months, home to frogs and mosquitos. If left for too long, pool surfaces begin to deteriorate.
The recent mortgage crisis has also brought about a pool crisis, with swimming pools all around the country sitting half empty and stagnant. In warm weather it creates a mosquito breeding area, and they also present a pool safety issue.
To Drain or Not to Drain?
For gunite pools, the decision may be easier. The pool probably should be drained and acid washed, for best results. For vinyl and fiberglass pools, draining the pool completely has an element of risk. Vinyl liners can relax with the water removed, and if the liner is very old, it may shrink and snap when drained. Fiberglass pools are relatively lightweight, and water removal can cause the shell to pop out of the ground, or shift slightly.
Recovering very poor water, can be a long process, with possibly hundreds of dollars spent on pool chemicals, before any headway is gained. And even though it eventually clears, it will contain the dead organic matter and the cellular memory , if you will - of the swamp it once was, making it more difficult to avoid future algae problems.
Another reason for draining the pool is to remove stains. Pools can soak up stains and deposits easily when neglected. Acid washing restores the finish by stripping away a tiny layer of plaster, exposing the fresh plaster underneath. You may also decide to drain the pool, in order to also make repairs to the plaster or fiberglass, or to replace the pool liner.
Drain the Pool
For pools that are very neglected, and with lots of debris, a Trash Pump would be the best choice. This can be rented for the day, along with a suction and discharge hose, and will drain a pool in under an hour. It can also suck up leaves and twigs, and solids the size of a golf ball, which means no dredging that muck out of the pool!
If the pool is fairly clean, without large debris, a smaller gas pump, or a submersible pump can also be used.
To prevent 'floating the pool', or having an empty pool pop out of the ground, follow these guidelines.
- Assess the topography. Is the pool on a hillside, or down in a 'holler?
- Avoid draining during or immediately after wet periods of heavy rain.
- Pump discharge water far away and downhill from the pool, or into a storm drain.
- When water reaches the floor, open the hydrostatic plugs in the floor (plaster pools only).
- Work fast, and refill the pool as soon as possible.
After draining, the pool can be pressure washed or acid washed (plaster pools only). Vinyl and fiberglass can be cleaned with a mild soap, and low-pressure washing. Acid washing is described on our website, but caution and care should be taken with chemicals such as muriatic acid, and to avoid slips and falls in or into an empty pool.
Don't Drain the Pool
For those of you who are dead set against draining the pool - for whatever reason, here are some alternatives to draining the pool. To recover water that is dark green will take some effort - and some time.
- Clean the pool using Leaf Nets and Leaf Baggers, to remove 99% of the organic debris. Even if you can't see the bottom, work the floor until your nets come up clean. This is an important step, so don't skimp here. Continue to skim and brush the pool daily during treatment.
- Balance the water. pH, alkalinity, hardness, stabilizer will likely all need adjustment. Check and readjust daily during the treatment process.
- Shock the Pool, until the water turns a blue-grey color. If it turns back to a light green color - hit it again! You'll need lots of pool shock, be prepared to use 5-10 lbs per 10,000 gallons of pool water! You will need to use enough to reach at least 30ppm.
- Run the filter 24/7 until the water clears, and resist the urge to clean the filter until the pressure gauge is 5-10 lbs higher. Use a filter cleaner, or change the sand or cartridge if it's not been done in many years.
- Use Clarifier to help coagulate suspended particles or use Flocculant to drop particles to the bottom.
- Fill the pool high with water and vacuum the pool to waste, by setting a multiport filter valve to waste (sand or DE filters). Brush again, it helps to lighten stains.
A No-Dran Acid Wash from United Chemicals can be used to remove most stains from a plaster pool, once the water is clear. For vinyl or fiberglass staining, check out Jack's Magic products.
When we were running pools, we had a piece of equipment we called the Rent-a-Filter; a large DE filter, with a pump. We could bring it out to your house, set it up on the pool deck and plug in the pump. Instant additional filter, for clearing up pools with poor filter systems.
A more advanced take on this is being done in Southern California (and other areas), with a form of water reclamation called the "Puripool Process". Pool Service Technologies, or PST, is a mobile water filtration unit visits the house and completely cleans and balances pool water. They are proud to boast of having saved 5 million gallons of pool water.
For those who have a water well on the property, filling an inground pool from the hose brings worry about "burning the pump up" or "running the well dry". In most cases, a pool can be filled from the well, but it can be a slow process. I recall one pool taking two weeks to fill, but I suspect the owner was only running it for 6-8 hours per day. Many pool owners with a well, would also like to avoid filling the pool with water high in minerals or metals.
Trucked in pool water is an option in most areas. It can be expensive, however. Depending on where you live, filling a pool from a truck (via a fire hydrant), can cost $1000 or more. A less expensive option may be to fill the pool halfway from a truck, and the rest from the well, or start it from the well, and if needed, finish it from the truck.