New Plaster Startup
A freshly plastered pool looks finished on day one, but the cement in the surface keeps curing for weeks. The water chemistry during that time decides whether the finish comes out smooth and even, or dusty, rough and blotchy.
What is actually happening
New fill water is undersaturated. It wants calcium, and it takes it from the most readily available source it can find: the still-soluble calcium hydroxide in the cement of your brand-new surface. Left alone, the water slowly eats into the finish you just paid for.
As calcium leaves the surface, fine white dust settles on the floor. Left there, it can scratch and etch the new finish.
Curing plaster pushes the pH up day after day. High pH clouds the water and leaves scale on the surface and tile.
An unbalanced startup can leave uneven color and a rough feel underfoot. Once the plaster has cured that way, it cannot be undone.
How we start up new plaster
Our startup balances the water as quickly as possible, then holds it there while the surface cures. Water balance is measured with the LSI (Langelier Saturation Index), and for new plaster we keep it slightly positive.
Acid wash first, not a hot start. There’s more than one way to start up new plaster. We prefer to acid wash the new plaster before the pool is filled, rather than a “hot start,” where acid is added to the fill water to bathe the new surface. Then we fill the pool and balance the water right away.
We add calcium and sodium bicarbonate to bring the LSI to +0.20 to +0.30, so the water is no longer pulling calcium from the plaster.
We visit every day the first week, test and adjust the water, and brush the whole surface to keep plaster dust from settling in.
New plaster keeps changing the water, so we keep visiting several times a week, brushing as needed and holding the balance until the surface has cured.
Your part
Getting a new plaster finish?
Startup is a separate service from Four Seasons Pool Service OBX, billed separately from the plaster work. Replastering itself is done by our sister company, Four Seasons Pool Builders.
