Free Shipping on orders over $99 FREE 365-DAY RETURNS
Filters Fast - Filter. Purify. Protect.

Filters Fast® FF20MBS-25 Replacement for Hydronix SDP-4520

SDP-4520

 5.00 (2) Read The Reviews!
Trustpilot (opens in a new tab)
$59.35
Retail: $69.29 /ea
You Save: 14%
Buy 1 - 5 for $59.35 ea.
Buy 6+ for $45.35 ea.
As low as
$59.35
Retail: $69.29
You Save: 14%
One-time delivery
Out of Stock
Notify me when this is available!
Auto Ship Icon Save up to 20% on first order, 10% on future orders and get FREE shipping on every order. Filtration essentials delivered on your schedule. Learn More about auto delivery
Frequently Bought With This Item

You'll save money with the Filters Fast® FF20MBS-25 Replacement for Hydronix SDP-4520 Water Filter, and provide enhanced water quality for your entire family. Instead of using a more costly radial-flow design, this carbon water filter is designed so that more water makes contact with the filtration media. The carbon material has two primary tasks: reduce chlorine taste and odor and trap sediment to make water appear clearer. Water fixtures can develop a hard scale as a result of what is in your tap water. Those issues can extend over to appliances that use the tap water and could reduce the life of the appliance due to clogs or decreased efficiency. Take control of your tap water woes immediately with this economical filter.

Specifications:

  • Brand: Filters Fast®
  • Part Number: FF20MBS-25
  • Alternative Part Number: AP817-2 FF
  • Replaces Part Number: SDP-4520
  • Pack Size: 1
  • Micron Rating: 25
  • Filter Media: Carbon Block
  • Filter LIfe: 6 months, based on water quality and usage
  • Flow Rate: 20 GPM

Compatible Parts:

The Filters Fast® FF20MBS-25 Replacement for Hydronix SDP-4520 is the correct replacement for the following part numbers:

Part Number
  • 36091
  • CTO20BB
  • P-RF-20BV
  • PP20BB-CC
  • RF-20BV
  • 3M AQUA-PURE 56027-07
  • 3M AQUA-PURE 5602707
  • 3M AQUA-PURE AP815-2
  • 3M AQUA-PURE AP817-2
  • 3M AQUA-PURE APWC815-2
  • AMERICAN PLUMBER 155247-51
  • AMERICAN PLUMBER WRC25-HD20
  • AMERICAN PLUMBER WRC25HD20
  • AMETEK RFC-20BB
  • AQUA FLO RF-20BV
  • BRUNER RFC-20BB
  • CULLIGAN RFC-20BB
  • Filters Fast FF20BBS-25
  • HYDRONIX SDP-4520
  • KLEEN PLUS RFC-20BB
  • OMNIFILTER TO8-20-SC2-S06
  • PENTEK 155247-43
  • PENTEK RFC-20BB
  • PENTEK RFC20-BB
  • PLYMOUTH PRODUCTS RFC-20BB
  • TIER1 RFC-20BB
  • USFILTER / US FILTER RFC-20BB
  • No results for {X}

Compatible Models:

The Filters Fast® FF20MBS-25 Replacement for Hydronix SDP-4520 is correct replacement for the following model numbers:

BrandModel NumberDescription
  • Hydronix HF45-20BLBK10 Filter Housing
  • Hydronix HF45-20BLBK10PR Filter Housing
  • Hydronix HF45-20BLBK15 Filter Housing
  • Hydronix HF45-20BLBK15PR Filter Housing
  • Hydronix HF45-20BLBK34 Filter Housing
  • Hydronix HF45-20BLBK34PR Filter Housing
  • Hydronix HF45-20CLBK10PR Filter Housing
  • Pentek 150111 Filter Housing
  • Pentek 150194 Filter Housing
  • Pentek 150233 Filter Housing
  • Pentek 150234 Filter Housing
  • Pentek 150235 Filter Housing
  • Pentek 150236 Filter Housing
  • Pentek 150239 Filter Housing
  • Pentek 150240 Filter Housing
  • Pentek 150467 Filter Housing
  • Pentek 166141 Filter Housing
  • Pentek 166142 Filter Housing
  • Pentek 166144 Filter Housing
  • Pentek 166227 Filter Housing
  • Pentek BBFS-222 Filter Housing
  • No results for {X}

Customer Reviews:

Total Reviews: 2 Average Rating: 5 / 5.0

Filtersfast Reviews on Trust Pilot external site (opens in a new tab)
Jeffrey Bartone2026-04-27

Good product for cost

Collected by Trustpilot.com
Jeffrey Bartone2025-10-12

Great product.

Collected by Trustpilot.com

Ask Our Product Experts

Related Categories:



Product Availability

Please provide your e-mail address below to receive a notification when this product becomes available:

X
X

Thanks! We'll send you a notification when this product is available!

Reorder Filters

Reorder Filters

Login. Confirm Order. Done
House Icon

Home Filter Club

Filtration essentials delivered on a customizable schedule.
Support Icon

Additional Questions?

Email us or call us at:

(866) 438-3458

Text us:

(704) 228-9166

Products

Refrigerator Water Filters Air Filters Water Filters Pool Filters Spa Filters Humidifier Filters

Company

About Us Reviews

Discounts & Rewards

Military Discount

Giving Back

Wine To Water Cystic Fibrosis Foundation Habitat for Humanity

Contact Us

Monday - Thursday

9am-12:30pm ET

1:30pm-5:30pm ET

Friday

9am-1:30pm ET

FAQs

Blog

Forums

©2005-2026 Filters Fast LLC . All Rights Reserved

Terms of Use Privacy Policy Accessibility Statement Sitemap Model Lookup
X
FILTERS FAST SHIPPING POLICY

Filters Fast offers economy free shipping every day on U.S. orders over $99 when shipping to the lower 48 states. This free shipping offer excludes Alaska and Hawaii, P.O. Box or APO/FPO/DPO and international orders. Orders under $99 ship for a fee to most destinations within the contiguous United States (excluding Hawaii and Alaska).

Filters Fast offers expedited shipping. When selecting any expedited shipping method, such as FedEx 2nd day or Overnight, your Transaction will be processed and Products shipped out the next business day. Business days are Monday through Friday. Any expedited delivery requests that are placed Friday through Sunday will not result in Products shipped until Monday. If the following Monday falls on a FedEx recognized holiday, your Products will be shipped on Tuesday.

Most Products ship within 1-2 business days after Transaction finalization, unless otherwise stated on the Product page on the Services. Your final shipping cost and estimated delivery time frame will be available to you during checkout.

We offer guaranteed same-day shipping on select Products with your preferred delivery method every Tuesday, Wednesday, and Thursday. When guaranteed same-day shipping is available on a Product, we will state this on the Product page, with the label "Ready to Ship". The "order within" countdown timer provides the window of time in which you must checkout to have your Products ship out the same day the Transaction is finalized. If a Transaction is finalized right at or after 2:00 PM EST, the applicable Products will ship the next business day. Our business days are Monday through Friday. Filters Fast also reserves the right, without cause, to make changes to any same-day shipping timeframe as same-day shipping may become unavailable within the allotted timeframe due to changes in inventory or high-volume capacity when you finalized your Transaction.

Once the shipping label is created, you will receive an email confirmation with the tracking information for your package. A Product with the "Ready to Ship" label does not apply to the delivery speed.

For expedited shipping, you will still need to select your preferred shipping method at checkout. Filters Fast is not responsible or liable for any shipping delays of any kind, including carrier delays, inclement weather, government restrictions, labor shortages, gas or utilities shortages, acts of God, etc.

Please note, some Products are special order and may require a longer ship-out and/or delivery time frame. These Product have a shipping timeframe stated on the Product page on the Services.

X

RETURNS AND REFUNDS POLICY

365-Day Satisfaction Guarantee

What You Need to Know:

Filters Fast is happy to accept returns on eligible items within 365 days of the original ship date. All returned Products are inspected and must be in a new, unused condition and contain all original parts, shrink wrap, protective seals, and components. Products with the "Satisfaction Guarantee Badge" are eligible for return in used condition. We will not accept the return of any other Products, including those that have been damaged other than by the applicable carrier, used, or do not contain all original parts, shrink wrap, protective seals, and components.

What Can Be Returned

Products are eligible for return if they:

Items That Cannot be Returned

We will not accept the return of any other Products, including those that have been damaged other than by the carrier, used, or do not contain all original parts, shrink wrap, protective seals, and components.

Items that cannot be returned:

Damaged or Defective Products

Water Quality Damages

Products damaged by water quality are not eligible for returns or refunds.

Installation Damage

Products damaged due to incorrect installation are not eligible for returns or refunds.

Product Misuse

Products that have been misused are not eligible for returns or refunds.

Shipping Damage

Filters Fast is not liable for damages to your Product(s) caused by the carrier. If your order arrives damaged, please report it as soon as possible through Your Account. Claims submitted within 365 days of the original ship date may be eligible for replacement or refund.

If you receive Products damaged by the carrier, we will work to resolve the issue, which may include you returning the Products to us. Please follow these steps to submit a claim for Products that the carrier damaged:

Return Restrictions

We encourage our customers to package their return carefully to avoid any damages in transit back to us.

Shipping & Return Labels

We gladly offer our customers free return shipping for eligible returns within the contiguous United States.

Customers in Alaska, Hawaii, Puerto Rico, and outside of the United States should contact our Customer Care Team for assistance.

Refund Information

We inspect all returned items when they arrive at our distribution facility. If you comply with the Returns Policy and your return is a result of a Filters Fast error in processing your Transaction or a defective Product that is protected by the Satisfaction Guarantee, we will refund the full cost of the Product. Additionally, if you comply with the Returns Policy and depending on the circumstances, we may refund the full cost of Products that are damaged due to the mishandling of the carrier.

Original outbound shipping charges are not refunded unless the return is a result of a Filters Fast error.

Refund Restrictions

After your return is received and inspected, refunds are typically processed within 1-2 business days. Depending on return shipping and your financial institution, the full refund may appear within 2-3 weeks. All refunds are issued to the original payment method.

Address Validation

Please double-check your shipping address before placing your order. Orders shipped to an incorrect address provided during checkout cannot be refunded or replaced until the original shipment is recovered.

Get Help and Support Need Help?
X
We use cookies to provide you with a better browsing experience. By continuing to browse, you are agreeing to our Cookie Policy.
Necessary Only
Accept