The Pentair 521357 IntelliChem Water Chemistry Controller provides advanced automated pH and ORP (oxidation‑reduction potential) monitoring for residential and commercial pool and spa systems. This controller‑only unit is designed to integrate with chemical dosing units—such as acid/base and sanitizer feeders—to maintain optimum water balance automatically, enhancing comfort, reducing chemical waste, and protecting equipment.

With intuitive digital controls and real‑time sensor feedback, IntelliChem ensures your pool’s sanitizer efficiency and pH levels stay within target ranges. Its robust design delivers dependable performance and helps minimize manual testing and seasonal water issues.

Pentair 521357 IntelliChem Water Chemistry Controller Compatibility

• Designed to integrate with chemical dosing systems (acid/base and sanitizer feeders).

• Works with Pentair automation platforms including IntelliCenter®, EasyTouch®, and IntelliTouch®.

• Compatible with standard pool and spa installations requiring water chemistry automation.

• Requires pH and ORP sensors and compatible dosing pumps (sold separately).

• Suitable for residential and commercial pool environments with chemical control needs.

Key Features

• Supplied under part number 521357 for exact-match ordering.
• Seals a specific housing — dimensions are not interchangeable between models.
• Ships from our US warehouse with tracking on dispatch.

Specifications

• Brand: Pentair
• Manufacturer part number: 521357
• Category: O-Rings & Gaskets
• Condition: New
• UPC / GTIN: 0788379807009
• Shipping weight: 13.3 lb

Frequently Asked Questions

What part number is this o-rings & gasket?

This item is supplied under part number 521357. Match that number against your equipment's parts diagram before ordering.

What lubricant should I use?

Use a silicone-based pool lubricant. Petroleum-based products swell and degrade the rubber, causing premature failure and leaks.

How do I identify the right o-ring?

Match the part number from the equipment's parts diagram. Measuring an old o-ring is unreliable because it stretches and compresses in service.

How often should gaskets be replaced?

Replace pump lid and filter gaskets whenever you notice air leaks, water seepage, or visible flattening and cracking. Many owners replace them annually at opening as cheap insurance.

How do I confirm this part fits my equipment?

Check the part number stamped on the component you are replacing, or find it on the parts schematic in your owner's manual. If the number differs or is unreadable, send us your equipment model and serial number and we will verify fitment before you order.

How quickly does this ship?

In-stock items ship from our US warehouse on business days. You will receive tracking by email once the order leaves the warehouse.

Can I return it if I ordered the wrong part?

Unopened, uninstalled items can be returned within 30 days. Equipment that has been installed or plumbed cannot be returned, so confirm fitment before installation.

Is this covered by a warranty?

Manufacturer warranty terms vary by brand and product. Warranty claims generally require proof of purchase and, on installed equipment, evidence of professional installation.