Pool ABCs
INSIDE YOUR POOL
Drain Grills
• The surface of the pool water is usually the most polluted part, with body oils and grease, sweat, skin debris and other pollutants usually within the top 6 inches. It is therefore essential that there is good surface skimming by either enough Skimmer units built into the pool shell, or by Level Deck surface skimming
• There must always be a minimum of 2 sump drains, at least 2 meters apart, in every pool. All sump drains must be directly connected to each other so that there can never be the possibility of only one suction point in operation. In practice this means that all the sum drains are interconnected in the base of the pool to one sump suction pipe which is routed to the plantroom. There have been too many accidents where swimmers (both adults and children) have been seriously injured or drowned through being caught against a single sump grill.
INSIDE YOUR POOL
Skimmers
• Since most of the pollutants are found at the water surface of the pool or spa. it is essential that there is a high percentage of surface skimming, especially on warmer pools where there is more body oil and grease lost to the water.
• By definition, Skimmers are constantly drawing the surface water where all the body oils and grease is present, and it is essential that regular waterline cleaning includes any dirt inside the skimmer body as well as the pool finishing around it.
INSIDE YOUR POOL
Level Deck Pools
• Also called infinity, negative edge, overflow pools and a lot of other names. Level deck pools are pools where the water is level with its deck. This is managed using drainage channels the collects the overflow of water into a balancing tank that collects the excess water created by bather or rain and also contains excess water to compensate for water drawn away by evaporation or splashes to make sure the pool continues to overflow.
• The Level Deck Drainage Channels should be capable of holding a certain percentage of the Surge Displacement volume
• The drainage pipes from the overflow channel to the Balance Tank should be capable of delivering more than the maximum total pool turnover rate into the Balance Tank.
INSIDE YOUR POOL
Balance Tanks
• The Level Deck Pool Balance Tank should be capable of taking the Total Displacement of the Maximum Design Bather Load or the Maximum Safe Bather Load - whichever is the greater. There should also be a provision for surge values (splash over or evaporation), and this volume will be determined by the type of pool and use it will receive when busy.
• It is important to remember that EVERY pool will generate a "Scum Line" of body grease and dirt at the waterline. In the case of a Level Deck pool, this Scum Line will be concentrated on the Balance Tank walls and must be frequently and regularly removed and cleaned.
• Balance Tanks are an extension of the pool itself, and must be treated as such.
• The Tank Shell Finish should be smooth to facilitate easy cleaning - ideally finished with large white tiles.
• Access to the inside of the Balance Tank should be easy and quick - to encourage regular inspections and cleaning.
• The Balance tank should be able to be easily drained and have sufficient headroom inside to allow regular inspection and cleaning.
• For safety reasons there should never be more than 3m of ceiling space without an access point in the Balance Tank - i.e. an operative inside the balance tank is never more than 1.5m from an access hatchway.