Swimming Pool Store

Perlite is a lightweight white granular substance that has its origin in volcanic rock.  Often used in potting soils, it is unique in that it is very lightweight.  Actually, when found in nature, the substance has a bit of water locked into it.  The raw perlite is heated in laboratory conditions until it pops something like popcorn into tiny, irregular lightweight puffs.  To become usable in a pool filter, these puffs are pulverized into powder.  

The resulting perlite powder is similar to diatomaceous earth, but is much more lightweight, making bags of it much easier to carry.  It is not as dense as diatomaceous earth (DE) and rinses off of swimming pool filter grids more easily.  Some people add DE to their swimming pool skimmer in the form of a slurry.  This runs down into the filter and sticks to the filter medium, reducing the size of particles the filter can remove.

Perlite powder can be used in exactly the same way.  The fact that it is so lightweight means that the when making the slurry, the perlite must be allowed to become waterlogged or it will float.  Other than that, it performs similarly to DE.  It can even be used in exactly the same amounts as DE.  In other words, if a homeowner had been adding 4 coffee cans full of DE to his pool, he could use 4 coffee cans full of perlite for the same results.

Perlite swimming pool filters are easier to backwash than DE filters because the grids don't get clogged as easily.  Homeowners can also wait longer between backwashes with perlite as compared to sand or DE in the pool filter.

Another good result has been in using perlite in filters for biguanide pools.  A biguinide pool is one in which an organic chemical called biguinide is used to purify the water instead of chlorine or bromine.  A shock product is used with these pools, which consists of hydrogen peroxide or something similar.  Biguinide pools are an alternative to the standard pools that rely so heavily on strong chemicals that can be toxic.

In one test of these alternative pools, three filter materials were compared.  They were DE, perlite, and cellulose fiber.  All three performed equally well, but the perlite was the first to clear up cloudy water and was the best at keeping it clear.  Perlite swimming pool filters could very well be the wave of the future.