Soft Opening: Try our new website.


CPR CS202 Overflow Box



  • For glass or acrylic aquariums up to 275 gal.
  • Flow rate 1500 GPH.
  • 9 3/8" wide
  • Dual 1" bulkhead outflow
A built in overflow is the most efficient method of draining aquarium water to a filter. If your aquarium does not have built-in overflow, CPR Continuous Siphon Overflows/Prefilters are the best means for getting water from an aquarium to a filter system without expensive modifications to the tank. They quietly skim up to six times more water than units with tubes.

The advantages of CPR Continuous Siphon Overflows/Prefilters include:
  • Adjustable water level allows you to easily change the level in your tank.
  • Black top reduces algae growth.
  • Quiet operation.
Tip: We recomond the use of an Aqua Lifter pump with the CPR overflows for trouble free operation. Another alternative is to hook the bleed hose from the overflow to the air intake of a power head. This way the overflow will continue to wok if it drawes some air into it or in the event of a power failure it will restart.

CPR Diagram

Model Width A B C D E F G H I J K L
CS50 6" 6 7/8" 8" 1 1/2" 1 7/16" 3 15/16" 4 3/4" 7 1/4" 5 9/16" 4" 3 3/16" 3 1/8" 2 7/8"
CS90 7 1/4" 7 5/8" 9 1/2" 1 5/8" 1 1/2" 4 1/2" 5 1/16" 8 5/8" 5 7/8" 3 7/8" 2 1/8" 3 5/8" 3 3/4"
CS100 9 3/8" 8" 10 1/4" 1 11/16" 1 1/2" 4 11/16" 5 1/16" 9 1/4" 6" 3 7/8" 3 1/4" 3 3/4" 2 3/4"
CS102 9 3/8" 7 7/8" 10 1/4" 1 11/16" 1 1/2" 4 5/8" 5" 9 1/4" 6" 3 7/8" 3 3/8" 3 3/4" 2 3/4"
CS150 9 3/8" 9 7/8" 10" 1 15/16" 1 1/2" 5 3/4" 5 3/4" 9" 6 7/8" 4 1/2" 3 11/16"" 5 1/4" 3 3/8"
CS202 9 3/8" 9 3/4" 10" 1 15/16" 1 1/2" 6 3/8" 5 3/4" 9" 6 3/4" 4 1/2" 3 5/8" 5 1/4" 3 3/8"

Product Manuals & Documentation

CPR CS202 Overflow Box

Owner's Manual available for download in Adobe PDF file format

Manufacturer Info

CPR Aquatic Aquarium Supplies
In Arcata, located in Northern California, the sea is a way of life. From the advanced Marine Biology department at Humboldt State University, just up the hill from CPR’s headquarters, to Humboldt Bay, about a mile west, CPR is nestled in a perfect environment to develop equipment for marine aquariums. CPR was started in a small garage in 1987 to produce biological filters for local aquarists. People who used CPR filters were impressed by the high quality and affordable prices. Word spread and the company grew. Since then, CPR has expanded to a 10,000 sq. ft. production facility and has developed many innovative products over the years. CPR is incorporating new ideas and technologies all the time. Their goal is to allow aquarists to place the highest performing products in their tanks at reasonable prices.

Ask a Question Earn 15 Points when you answer a question
Sort By :
9 Questions
Displaying questions 1-9
I just purchased a CPR CS202 Overflow Box. Can I use the CPR 1-1/4 inch Drain Hose with this overflow box? If so, what other parts would I need to attach the drain hose to the overflow box?
Asked : Nov 01, 2018
By : Sid Cooley

Free, Fast, and Flexible Shipping Options

  • $5.99 flat rate shipping for orders under $39

    Most orders under $39 ship for only $5.99 using a mix of economy shipping methods including UPS Ground, USPS First Class, and/or SurePost. Your order will be delivered in up to 7 business days after it ships out.

  • free shipping for orders $39+

    We ship 99% of the products we carry for free within the contiguous United States using a mix of economy methods including USPS First Class Mail, SurePost and UPS Ground. Your order will arrive in up to 7 business days. Just spend $39 or more!

  • free faster shipping for orders $250+

    Over 90% of shoppers receive their orders within 1-2 business days. Upgrade from free economy shipping to faster shipping for only $5.99—or spend $250 and we'll upgrade you automatically!

  • need your order even faster? no problem!

    Expedited shipping services are available for most products if you are in a hurry. Get guaranteed delivery in 2 business days, 1 business day, or next day by 10:30 am. Costs vary by location.

  • buy it today and we'll ship it today

    Same-day shipping is available Monday-Friday for most products—place your order by 10:30 am PST. Pre-ordered and back-ordered items do not qualify, nor do drop-shipped, live, or frozen shipments.

  • live plants, live foods, and frozen foods delivered to your door

    We ship live plants, live foods, and frozen foods within the contiguous United States. Each of these categories is subject to its own $19.99 flat-rate shipping fee to cover the special packaging and/or expedited shipping costs required to ensure safe delivery. Orders with 12+ live plants ship free!

Learn More About Shipping

60-Day Return Period with Easy Online Returns

Return any new and unused item within 60 days for a full refund. Having difficulty with a product? Contact us to speak with an aquarium expert. If you need a replacement, fill out this form.

A small segment of the 180+ brands we carry require that customers contact them directly if/when problems arise. You can view the full list of those brands and get their contact info here.

We are unable to accept returns of Digital Aquatics, Neptune Systems, Vertex Aquaristik, Aqua Illumination (AI), EcoTech Marine, GHL, or Seneye products once the manufacturer's packaging seals have been broken.

Marine Depot is an authorized reseller for every product we carry. That means when you buy aquarium supplies from us, your products are not only backed by our own 60-day return policy, they also carry full factory warranties, where applicable. Some items have a 1-year warranty, others have limited lifetime warranties. Warranty coverage varies from manufacturer to manufacturer, so please read the product description of the item(s) you are considering thoroughly for details or contact us if you have warranty questions.

Learn More About Returns

Earn 5% Cash Back for Most Purchases

Rack up reward points to earn discounts on future purchases! You can earn reward points by creating an account, writing reviews, referring friends, subscribing to our newsletter, buying products, and more!

  • Earn 5 reward points for every $1 you spend to get 5% cash back
    Most Products
  • Earn 1 reward point for every $1 you spend to get 1% cash back
    Abyzz, American Marine, AquaIllumination, AutoAqua, CoralVue, Digital Aquatics, EcoTech Marine, Giesemann, GHL, Hanna Instruments, Hydor, IceCap, Innovative Marine, Iwaki, Kamoer, Kessil, Klir, Korallen-Zucht, Maxspect, Mur-lok, Nano Box, Neptune Systems, NYOS, Oceanbox Designs, Pax Bellum, Radium, Red Sea, Reef Glass, Reef Octopus, Seneye, Somatic, Tunze, Vertex Aquaristik, and Waterbox Aquariums

You can also get bonus reward points by purchasing select items during special sales and promotions.

Learn More About Rewards