POOL CARE GUIDE

This can be due to the high pH level causing the calcium in the water to precipitate out of solution and plate onto the surface. It can also be due to calcium levels being out of recommended limits or a higher water temperature.

Occasionally, despite the correct level of chlorine being present on testing, algae may have developed. This may be because the levels fluctuated previously or there is poor water circulation due to inferior pool design. When water circulation is poor algae spores are protected by stale/dead water on the surface. As soon as there is a drop in the free chlorine level, algae growth will accelerate.

If scale hasn’t been on the surface for too long, lower the pH to between 6.5 and 6.8 (using hydrochloric acid). Leave at this level for approximately 1 week and brush the affected areas over the duration to remove the scale. Take a water test and balance accordingly. Monitor the surface texture of the pool daily. If the surface becomes rough over exposure may occur. To prevent over exposure, increase the pH with pH Increaser as soon as excessive roughness is detected.

After performing this procedure, it is imperative that calcium levels in the water are returned to recommended levels (200-250ppm).  Failure to do so could cause excessive acid demand which inturn will weaken the surface and may lead to other problems.

If scale has been on the surface for a number of months then the pool will most likely have to be drained and acid washed, then filled up and re-balanced.
Experienced pool technicians may add acid (10-15L for average 50,000L pool) to the pool the day before it’s drained to soften the calcium.  The pool is then drained and using a high-pressure cleaner, the calcium is water blasted off.  The pool is then refilled and rebalanced.

To avoid future calcium scale occurrences, maintain Cal-Stop in your pool water.  This can be achieved by purchasing a bottle of Cal-Stop from your local pool shop every 6 months.  Cal-Stop keeps calcium in solution even if the pH level does increase.  If your local pool shop doesn’t stock Cal-stop then please order online here.

If scale hasn’t been on the surface for too long, lower the pH to between 6.5 and 6.8 (using hydrochloric acid). Leave at this level for approximately 1 week and brush the affected areas over the duration to remove the scale. Take a water test and balance accordingly. Monitor the surface texture of the pool daily. If the surface becomes rough, over exposure may occur. To prevent over exposure, increase the pH with pH increaser as soon as excessive roughness is detected.

After performing this procedure, it is imperative that calcium levels in the water are returned to recommended levels (200-250ppm).  Failure to do so could cause excessive acid demand which inturn will weaken the surface and may lead to other problems.

To avoid future calcium scale occurrences, maintain Cal-Stop in your pool water.  This can be achieved by purchasing a bottle of Cal-Stop from your local pool shop every 6 months.  Cal-Stop keeps calcium in solution even if the pH level does increase.  If your local pool shop doesn’t stock Cal-stop then please call River Sands on (07) 3412 8111 Brisbane callers or 1800 077 744 Toll Free for supplier near you.

If scale has been on the surface for a number of months then the pool will most likely have to be drained and acid washed, then filled up and re-balanced.  Experienced pool technicians may add acid (10-15L for average 50,000L pool) to the pool the day before it’s drained to soften the calcium.  The pool is then drained and using a high-pressure cleaner, the calcium is water blasted off.  The pool is then refilled and rebalanced.

To avoid future calcium scale occurrences, maintain Cal-Stop in your pool water.  This can be achieved by purchasing a bottle of Cal-Stop from your local pool shop every 6 months.  Cal-Stop keeps calcium in solution even if the pH level does increase.  If your local pool shop doesn’t stock Cal-stop then please call River Sands on (07) 3412 8111 Brisbane callers or 1800 077 744 Toll Free for supplier near you.

• It may be possible to expose more of the coloured aggregate in the walls thereby darkening them and providing a better match, and/or;
• Polishing the joint line and the floor. Polishing slightly lightens the surface as glaze is removed from the coloured aggregate.

After performing either of these procedures it pays to pressure wash the entire surface, as this will remove excess oxide. Doing so helps to even out colour variations.
Whilst it may not be possible to completely eliminate all the colour variation, the solution described above will certainly help. Over time the discrepancy will reduce of its own accord as the cement sits immersed in water and fully hydrates.

Pay particular attention when acid washing to make sure acid is not allowed to sit on the floor of the pool. Ensure that a wet edge is maintained at all times.
Also consider:

• Ensuring adequate trowel hands are available.
• Reducing the length of the wet edge by working across the pool rather than doing the walls first then the floor.
• Avoiding cross trowelling at joins, i.e. when joining the walls to the floor, attempt to trowel the floor in the same direction as the walls.
• Ensure batches of stock are mixed evenly from different production dates.

• Ensuring adequate trowel hands are available.
• Reducing the length of the wet edge by working across the pool rather than doing the walls first then the floor.
• Avoiding cross trowelling at joins, i.e. when joining the walls to the floor, attempt to trowel the floor in the same direction as the walls.
• Ensure batches of stock are mixed evenly from different production dates.

• Acid being left too long on the surface during the acid wash/acid bath causing an excess of cement to be washed away which leaves remaining aggregate protruding from cement (over exposure of aggregate).
• Acid must always be diluted when added to pool water. If it’s not and is added to pool water, the acid will sink to the bottom and overexpose the surface (acid is heavier than water).

Note: If rough patches are lighter or dull in colour, refer to Calcium Scale questions.

Ensure that any acid to be added to the pool is always diluted.