How to Install a Skimmer on a DIY Hot Tub or Plunge Pool

Last updated: September 2026

If you’re building a DIY hot tub or plunge pool with a skimmer, installing it correctly matters. The skimmer keeps the water clean and sets your water level, and it’s very hard to fix once it’s concreted in. This guide covers what it does, which type to choose and how to install it.

What does a skimmer do?

A skimmer is part of the circulation system and does two main jobs:

1. Debris collection and filtration.
2. Water level regulation.

Debris collection and filtration

The skimmer sits at the surface and collects floating debris, such as leaves and insects, in its basket. Smaller contaminants like oils, lotions and fine particles are drawn in with the pump’s suction. They’re then sent to the filter and trapped, so they don’t recirculate.

The skimmer works alongside the bottom drains, which pull water from the base of the tub or pool, giving a balanced flow. In larger pools, skimmers and bottom drains are normally on separate suction lines controlled by a manifold so you can adjust how much each draws. In a hot tub they may be connected together, depending on the size and design. See DIY hot tub plumbing and installing a main drain.

Water level regulation

The second job is setting the water height. Ideally the water level lines up with the middle of the skimmer opening. That leaves enough capacity for the water displaced when you get in, so it doesn’t overflow, and keeps the skimmer working efficiently. If the level is too high, the skimmer can’t skim properly, and if it’s too low, the pump can suck air.

Choosing the right skimmer

For DIY hot tubs and plunge pools I recommend a concrete skimmer rather than a liner skimmer. Concrete skimmers are designed to be built into solid concrete or block walls, so they suit durable, long-lasting installations. They look something like this.

How to install a skimmer

Lots of DIY builders ask me about this, so here’s the step-by-step.

Step 1: set the correct height

The most critical part is the height. The centre of the skimmer opening should line up with the intended water level of your tub or pool, allowing for displacement.

Pro tip: double-check your measurements before you fix the skimmer in place. A small mistake, such as too high or too low, affects how it works and how the tub looks. I learned that the hard way, so you don’t have to. Remember to allow for the final finish: tile, adhesive, render and coping all change the height. My in-ground hot tub build guide has the build-up.

Step 2: integrate it into the wall

Hot tubs are smaller than pools, and a big skimmer extension throat can look ugly. If your wall is thicker than the skimmer, build the neck out in concrete instead so it blends into the wall. Check out wall construction options for typical wall thicknesses.

For example, one of our DIY builders, Amanda, started a project in New Orleans. Her skimmer’s neck was shorter than the wall was thick, so she extended the opening with concrete to get a clean, flush finish.

Step 3: tile around it

Once the skimmer is set, tiling around the opening improves the look. Some builders tile over the plastic skimmer face and leave only the water entry visible, which gives a polished, professional finish. Don’t forget the waterproofing detail around the skimmer body: see waterproofing, grout and tile adhesive and hot tub tiles.

Trey, another DIY builder, from Germany, built his skimmer into a cylindrical tub and tiled around the edges, for a seamless look that blends with the design. You can see more of his build in Trey’s hot tub build.

Should you use the skimmer for chemicals?

It’s a common debate in the DIY community. Some people prefer floating dispensers. Others, including me, find it convenient to put chemicals in the skimmer, and I’ve found no harm doing so. It’s your choice, but do it sensibly: only with the pump running, never mix different chemicals in the basket, and don’t leave strong chlorine tablets sitting next to fittings. See the guide to balancing chemicals for the safe ranges.

Common mistakes

• Setting the skimmer too high or too low relative to the intended water level.
• Forgetting to allow for tiles, render and coping when setting the height.
• Using a huge extension throat on a small tub instead of building out the neck.
• Not waterproofing properly around the skimmer body.
• Using a single suction only. Always keep the bottom drains as well.

Planning your own build?

Where the skimmer, drains and returns go is all laid out in my DIY hot tub plans, along with the plumbing diagrams and a shopping list. For a custom plunge pool or hot tub, I can draw up architectural CAD and a 3D plumbing design. If you need parts, look at parts4tubs.com (USA) or parts4tubs.co.uk (UK). For more on plunge pools, read building DIY plunge pools.

FAQs

How high should a skimmer be set?

The centre of the skimmer opening should line up with your intended water level. Allow for the thickness of tile, adhesive and render when you set it.

Do I need a skimmer on a DIY hot tub?

Most DIY hot tubs and plunge pools use one to collect surface debris and set the water level, together with bottom drains. Some designs use an overflow trough instead.

Concrete skimmer or liner skimmer?

For concrete or block walls, use a concrete skimmer. Liner skimmers are made for vinyl-liner pools.

Can I tile over a skimmer?

Yes. Many builders tile around the opening and even over the plastic face, leaving only the water entry visible.

Can I put chemicals in the skimmer?

Many people do, and I do, with the pump running. Don’t mix chemicals in the basket and be careful with strong tablets near fittings.

Got a question about your own build? Drop it in the comments below. I read them all.

Cheers,
Andi

You can also find me on my socials;

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi