The interior finish is the surface you look at and touch every time you use the pool, and it is chemically active and vulnerable during its first weeks in water. What happens in those thirty days is largely irreversible. A finish that gets a poor startup carries mottling, staining or roughness for its entire life, and no amount of later maintenance corrects it.
This is the part of a pool build that owners are most often asked to participate in and least often told why.
Fill the pool without stopping
Once filling begins it should continue without interruption until the water reaches the correct level. A pause leaves a visible line at the water surface where the exposed and submerged plaster cured differently, and that line is permanent.
Plan the fill: know your water source and its rate, and if you are on a well, confirm it can deliver the volume without running dry. Some owners in the Triad arrange water delivery for exactly this reason. Fill through a hose placed to avoid the water jetting directly against the fresh finish, and follow your builder's instructions about a pre-filter if your fill water carries iron or minerals.
Brush, more than you expect
New plaster releases a fine dust as it cures, and that material has to be brushed into suspension so the filter removes it. If it settles and sits, it can bond to the surface and leave permanent rough patches or discoloration.
The typical instruction is brushing the entire pool multiple times a day for the first several days, then daily for the first couple of weeks. Use a brush appropriate to the finish type, since the wrong brush on some surfaces causes damage. Brush walls, floor, steps, benches and behind fittings, not just the easy areas.
This is genuinely the most important thing an owner does during startup, and it is the thing most often shortchanged.
Chemistry during the startup window
New plaster raises pH as it cures, and left alone the water goes high, which causes scaling and cloudiness on a brand-new surface. Meanwhile, water that is aggressive or unbalanced in the other direction etches the finish.
Startup regimens differ by finish type and by builder, and the right approach for a standard plaster differs from a pebble or quartz aggregate finish. Follow the specific regimen your builder provides rather than a generic internet procedure, and test frequently — often daily — during the first weeks.
Two things to be careful with: avoid adding anything that could stain a fresh surface, and do not put chlorine tablets in a floater that can rest against the plaster, because a tablet sitting on a new surface bleaches a permanent spot. Keep the water circulating continuously during this period.
Stay out for the period specified
Your builder will specify when swimming is permitted, and it varies by finish. Beyond that, avoid anything abrasive in the pool, do not use an automatic cleaner until the finish has cured and the builder approves it, and keep pets out during the initial period.
Do not add salt to a saltwater system until the specified time has passed. Adding salt too early is a common and avoidable mistake on new finishes.
What normal looks like
Some variation in a new finish is normal and not a defect. Plaster and aggregate finishes are hand-applied and mineral-based, so slight color variation and mottling occur, particularly with darker colors, which show variation more readily than lighter ones.
What is not normal is significant streaking, large discolored areas, rough patches, or visible crazing beyond fine surface checking. Raise those with your builder during the startup period rather than a year later, and document with photos and dates.
Where problems come from
- Interrupted fill leaving a permanent water line
- Insufficient brushing letting curing dust settle and bond
- pH allowed to climb, causing scale on a new surface
- Unbalanced or aggressive water etching the finish
- A chlorine tablet or floater resting against the plaster
- Fill water with iron or manganese depositing on a fresh surface
- Adding salt too early
- Using the pool or a cleaner before the finish has cured
Keep records
Log your test results, what you added, and when you brushed through the startup period. If a question about the finish comes up later, that record is what distinguishes a product or workmanship issue from a startup issue, and it protects you.
We provide a written startup regimen and stay involved through the first month on every pool we build. Get in touch or call Oasis Pools at (336) 471-0103.