Does it fit all hot tub models?

No; They specifically fit Watkins Hot Spring 3.5" standpipe caps; includes 1 gray cap replacing part 36513 for your silver ion line and 2 white caps replacing part 31389; please verify your model compatibility before ordering

Is it easy to install?

Yes; tool free installation takes less than a minute; simply power off your hot tub; unscrew your old brittle cap counterclockwise; thread your new replacement cap on clockwise until hand tight for a straightforward stable fit

How often to replace?

These caps typically last two to three years; replace them immediately if you notice surface cracking or structural brittleness from heavy chemical or UV exposure; proactive replacement ensures your filter remains locked down safely

Why you might like this?

This 3-pack delivers exact color unified matching at a fraction of factory cost; made of reinforced PP to lock filters vertically; features zero chemical conflicts with saltwater systems while protecting your pump from bypass debris

What happens if I don't replace a brittle or cracked standpipe cap?

Cracked or brittle caps allow loose debris to bypass filter pleats and flow into plumbing lines; presents an immediate risk of catastrophic heater or pump clogging; replacing your caps proactively safeguards your hot tub investment

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Fully operational. Shipping worldwide, on schedule.Duty & taxes paid at delivery

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3.5" Standpipe Caps for Watkins Hot Spring Spas 36513 & 31389

3.5" Standpipe Caps for Watkins Hot Spring Spas 36513 & 31389

Product ID: 392273651

Details

Brand
HOTUBJOY
Color
White Grey
Product Dimensions
1.7"L x 3.2"W
Material
Reinforced
Shape
Round

🎨Exact color-coded caps for easy visual ID

🔧Tool-free, hassle-free drop-in installation

🛡️Reinforced break-resistant polypropylene housing

€ 44.32

Duties & taxes included

In stock

Sold byAmazon SlovakiaDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

Buyer Protection · Full refund if your order doesn't arrive as described.

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Details

Brand
HOTUBJOY
Color
White Grey
Product Dimensions
1.7"L x 3.2"W

Description

🛁 Lock in luxury, block out debris — spa care made effortless!

DEBRIS DEFENSE SYSTEM - High-precision threaded caps block dirt and debris, safeguarding your spa’s inner plumbing.
PRECISION COLOR CODING - Gray & white caps eliminate guesswork, streamlining your spa maintenance routine.
SECURE ANTI FLOAT LOCK - Keeps your filter stable and water flowing cleanly, preventing costly pump damage.
DURABLE REINFORCED BUILD - Premium polypropylene resists cracking, chemicals, and heat for long-lasting spa protection.
SEAMLESS SPA COMPATIBILITY - Perfectly engineered to replace original Watkins Hot Spring Spa parts 36513 & 31389.

The HOTUBJOY 3-Pack 3-1/2" Stand Pipe Caps are precision-engineered replacements for Watkins Hot Spring Spas, featuring color-coded, reinforced polypropylene caps that resist harsh chemicals and heat. Designed for tool-free installation, these caps prevent debris entry and secure your spa filter to protect pumps and heaters, ensuring a flawless, worry-free spa experience.

Specifications

Brand	HOTUBJOY
Color	White
Item Dimensions L x W x H	3.2"L x 3.5"W x 1.7"H
Material	Plastic
Material Type	Plastic
Model Name	3-1/2" Cap
Product Dimensions	3.2"L x 3.5"W x 1.7"H
Shape	Round

Reviews

J**F

Great product

Perfect fit

30.05.2026

A**E

Perfect fit

Perfect fit for my hot springs tub

26.07.2026

M**N

Perfect fit just like oem

I have a hot springs tx2 I bought used and it was missing the filter cap. These fit perfectly

14.07.2026

J**Z

Filter Caps

Parts fit right on. NP's

10.07.2026

D**.

Perfect replacement

Perfect replacement for my aged hot springs tub!

13.11.2025

J**.

Strap Clips

Two of the plastic strap clips broke the first day. I wish they would use better/stronger clips for the tie downs.

20.11.2024

B**D

Fit as hoped for

Gathers unwanted items to keep water clean and free of bugs

18.04.2026

L**A

Worked fantastic!

8.05.2026

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