Vinyl Inground Pool Liner or Fiberglass Swimming Pool Startup

orenda startup for vinyl liner or fiberglass

How to Fill a Fiberglass or Vinyl Liner Pool

Based on 10,000 gallons (37,855 L)

Vinyl and Fiberglass Startup PDF


The Orenda Startup™ is an LSI-focused procedure to balance water during initial fill up. It is most important for pools with cement-based finishes, like plaster, quartz, and pebble. Since this procedure is about non-cement surfaces–vinyl liner and fiberglass pools–the urgency of LSI adjustment is less. LSI balance is still important, but can be done during fill up or once the pool is full. This procedure walks you through the best-known practice, which is adding chemicals while the pool is filling, and the next day.

Related: How to Implement the Orenda Program

You will need:

Fill Up Day

  1. Test the tap water, and input results into the Orenda App’s LSI Calculator under “current levels” on the left. 
    • Adjust the right side of the calculator to have an LSI between  0.00 and +0.30 .
    • Be sure to have enough calcium chloride, sodium bicarb, and muriatic acid on site.
  2. Pre-dissolve calcium chloride (OR sodium bicarb, but never the two at the same time) in buckets of water, or in The Orenda Startup Barrel™.
    • Mix calcium with half the dose of purge of SC-1000, and some muriatic acid to offset the alkaline pH of SC-1000. The purge dose of SC-1000 is 32 oz per 10,000 gallons of water.
      • 12 fl.oz. of muriatic acid offsets the high pH of one quart (32 fl.oz) of SC-1000.
      • If the tap water pH is 8.0 or higher, consider adding some additional muriatic acid to the calcium buckets to keep the entire pool between 7.6-8.0 pH. Do NOT add muriatic acid directly to the pool without pre-diluting in water first.
  3. Begin filling the pool, and within the first few minutes of filling, add the other half of the purge dose of SC-1000 to the water. Continue filling the pool without interruption.
      • 16 oz per 10,000 gallons of water is half the purge dose of SC-1000, and it is devoted to help pre-dissolve calcium chloride. But if you are adding sodium bicarb on fill day, all the SC-1000 purge dose goes into the pool.

Day 1: Chemical Adjustments

  1. Test the water chemistry and use the Orenda App to adjust LSI. Usually this means adjusting alkalinity and pH (or if you added bicarb on fill day, you would adjust calcium hardness and pH on this day).
  2. Turn on circulation system and proceed with normal startup protocol.
    1. Brushing and vacuuming should be done with tools compatible with the type of pool you have. Do not use a brush or vacuum not approved by the pool manufacturer.
  3. Add non-stabilized chlorine, and follow the vinyl liner or fiberglass manufacturer’s recommendations.
  4. Add purge dose (32 fl.oz./10,000 gallons) of CV-600 enzymes directly into the skimmer or around the perimeter of the pool.

Additional information

Once the LSI is balanced, follow normal protocol, per the vinyl liner or fiberglass manufacturer.

More Questions?


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