Great Aquariums Start Here
Live Chat Support
    Free Shipping
  • FREE Shipping ON $75+
  • 14-Day Low Price Guarantee
  • Low Price Guarantee
  • Same Day Shipping
  • Same Day Shipping
99% of items we carry qualify for FREE SHIPPING in the contiguous United States if you spend $75 or more. Learn More
If you find a product we sell for a lower price at another online store, we will match their price to ensure you always pay the lowest amount when you shop with us. Learn More
Same Day Shipping
We promise to ship your order as fast as humanly possible. In fact, 99% of orders placed before 2 pm EST ship the same day! Learn More
Home » Saltwater Aquarium Supplies  » Overflow Box  » External Boxes  »  Marine Depot Overflow Box OF-300
Marine Depot Overflow Box OF-300

Marine Depot Overflow Box OF-300

Write A Review
Product Review
We value your opinion & experience
Thank you for taking the time to review our products!

This is a Product Review for: Marine Depot Overflow Box OF-300
Name to display on the review:
Location (ex: Anaheim, CA):
Your experience level:
How would you rate this product?
Review Title:
Write your review:
(Please focus on product quality and performance)
In Stock: Order by 2PM EST for same-day shipping (M-F)
This item is in stock in our East and West Coast warehouses
Item #:
Notify Me
Just enter your email address below and we'll let you know when the product you are looking for becomes available!

Item Code:
Your Email:
Add to Cart or Notify Me
This item is temporarily unavailable but will be back in stock soon.

Item #
Click the Add To Cart button below if you'd like to reserve this item today. Any other items included in your order will be immediately processed and shipped. We will ship this item separately as soon as it arrives. We will not charge you for this item until it ships and you will incur no additional shipping charges.
Enter your email address in the field below and click the Notify Me button if you'd like us to send you an email when this item becomes available. Although you will be immediately notified when we have stock on hand, we will not reserve any units for you; you must return to our website and place an order.

+ Add to Wishlist
Add to Wishlist
Select Wish List:
Comments (up to 200 characters):
Quantity Desired:
Quantity Received:
FREE Shipping Promo offers FREE standard ground shipping via UPS on orders of $75 or more for orders containing non-overweight or oversize items (orders which do not qualify for our FREE shipping promotion will still be shipped at a discounted rate).

Terms and Exclusions:
  • Offer valid only on orders shipping within the contiguous United States. Orders shipping to Alaska, Hawaii, Puerto Rico, Guam or other US Territories do not qualify for this promotion.

  • This promotion does not apply to items requiring expedited shipping, such as refrigerated products, frozen products or live rock.

  •'s FREE shipping promotion does not include products sent in oversized or particularly heavy boxes. This may include but is not limited to aquariums, canopies, chillers, external water pumps, metal halide magnetic ballasts, stands and substrate/sand. These items may be subject to additional shipping handling charges. Should shipping surcharges apply, they will be noted on individual product pages and / or displayed during check-out. We will, however, pay a portion of the shipping charges for these orders.

  • Shipping surcharges, such as special handling are NOT covered under the FREE shipping promotion.

  • Shipping charges for returned merchandise is non-refundable. Please read's Return PolicyPolicy for more information.

  • Price matched (Low Price Guarantee) or discounted orders do NOT qualify for our free shipping promotion.
If you find a product we sell for a lower price at another online store, we will match their price to ensure you always pay the lowest amount when you shop with us.

Enter the price, shipping cost and website address where you found the lower price. Then click the "Add to Cart" button. We will review the lower price while processing your order and make any necessary reductions before your order ships. Some restrictions apply. See Terms & Conditions.
Shipping Cost*
Competitor's Website*
*Required information
Marine Depot 60-day Returns
At Marine Depot, we stand behind our products. That is why we offer a 60-day return period: one of the best in the industry! Learn More

Marine Depot Overflow Box OF-300 Information

Product Manuals & Documentation

High quality and economical hang-on overflow box allows you to easily add a sump, refugium or wet/dry filter to your system. U-tube design allows for easy and convenient installation. Adjustable pre-filter hight allows you to adjust the water level inside your aquarium.

  • 1" Bulkhead
  • U-tube
  • Noise-Reducing Cylinder Foam Sleeve
  • Nylon screw and wing nut
  • Surface Skimmer Box
Model Tank Size Overflow Body
Surface Skimmer
Max. Flow Rate Drain Size
Nano up to 30 Gal 4"x2.5"x8" 4"x1.5"x6" 200GPH 3/4"
OF-300 up to 60 Gal 6"x3"x10" 6"x2.5"x6" 300GPH 1"
OF-800 up to 120 Gal 8"x3"x10" 8"x2.5"x6" 800GPH 1"
OF-1000 up to 150 Gal 9"x3"x10" 9"x2.5"x6" 900GPH 2 x 1"
OF-1200 up to 200 Gal 10"x3"x10" 10"x2.5"x6" 1000GPH 2 x 1"
OF-1800 up to 320 Gal 12"x4"x10" 12"x2.5"x6" 1600GPH 1-1/2"

Manufacturer Info carries more than 7,500 popular and hard-to-find aquarium supplies and fish tank accessories for saltwater and freshwater aquariums. You’ll find the top aquarium equipment and aquarium accessories from Hagen, Red Sea, Eheim, Coralife and many more. All of our aquarium pet supplies carry a 60-day money-back guarantee and we offer a Low Price Guarantee on all in-stock aquarium products. We ship 99.9% of fish tank supplies the same business day if you place your order before 6 PM EST. If you have any questions about fish supplies please do not hesitate to contact us. We’re here to help!
Do you have experience with Marine Depot Overflow Box OF-300?
Be the 1st to review!
WIN A MEDIA REACTOR! Sign up for hot deals, helpful videos, and a chance to win an Accel Aquatics FR-30 Media Reactor!