Robot cleaners on fibreglass pools

Fibreglass pools have a gel coat finish. It's the surface your robot drives on, and two things about it matter: it's smooth, and it can mark.

How a robot moves on it

One maker says smooth surfaces such as fibreglass allow cleaners to move with less resistance.¹ The same maker says consistent contact between the cleaner and the surface is important for effective debris collection.¹

How the cleaning works on gel coat

Debris on this finish tends to sit on top. One maker calls fibreglass smooth and non-porous, so debris rests on the surface instead of embedding. Lifting it cleanly depends on steady suction contact rather than hard scrubbing.² Another maker says consistent contact between cleaner and surface matters for collecting debris.¹

Can a robot mark the gel coat?

Gelcoats are designed to be durable, says a general reference.³ Makers still add cautions. One says a smooth gel-coated pool shows fine scratches more readily than concrete.⁴ The same maker says any hard, abrasive object dragged repeatedly over gelcoat can dull or mark it over time.⁴

Notice that this is about hard, abrasive things and repeated dragging. The manual for your own robot is where the maker says which brushes and tracks suit a gel coat.

Practical checks

• Read the manual's list of surfaces and look for fibreglass or gel coat by name.
• Check the brush and track materials the maker pairs with it.
• Follow the manual's maintenance schedule for the filter, brushes and tracks.
• Ask the maker if the manual doesn't say whether your model suits fibreglass.
• Look at the tracks and brushes for stones or sharp debris before each run.
• Follow your model's manual for lowering it in and taking it out.

Where to get a firm answer

Blog posts from makers describe pools in general. Your own manual and your pool's installer describe your robot and your shell. Where the two seem to differ, the manual for your model comes first.

Two sides of one finish

Put the makers' points side by side. A smooth, non-porous gel coat means debris rests on top, which suits suction cleaning.² A smooth gel-coated pool also shows fine scratches more readily than concrete.⁴ None of this says a robot is wrong for fibreglass. It says the match between robot and surface is worth checking in the manual before the first run.

Found a mark? Don't guess, and don't try to polish or repair it yourself before you've asked. Ask the pool's maker or your installer, since they know the coating on your particular shell and what it can take.

To compare fibreglass with the other finishes, start with how grip and wear work. Unsure what you have? Look at the wall and edge.

No swimmers while it runs. Power supplies near water follow the manual, every time.