Penn-Plax Cascade 300 Hang-On Power Filter
- 300 GPH flow, for tanks up to 100 gallons
- Quad filtration: carbon, floss, Bio-Sponge and Bio-Falls
- Adjustable flow knob
- Hang-on design with an extendable lift tube
- Freshwater and saltwater tanks
- Monthly cartridge change recommended
- 11.25 W x 6.25 D x 8.25 H inches
Last refreshed Jul 1, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A hang-on power filter with adjustable flow and four filtration stages for freshwater or saltwater tanks. The listing itself warns that it makes some noise, which matters near a bedroom.
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ASIN: B0002DJ82GModel: Cascade 300Category: Aquarium Filters
Overview
A freshwater or saltwater aquarium within the listed tank size is where this hang-on filter works. Water travels up a lift tube, passes through a carbon and floss cartridge and a separate Bio-Sponge, then returns over a Bio-Falls outflow that adds oxygen.
An adjustable flow knob, a replaceable carbon and floss cartridge and a separate Bio-Sponge for biological filtration give a full filtration path in one hang-on body. The limitation is sound, which the seller states plainly, along with a cartridge that needs regular replacement.
Who it's for
A hobbyist running a larger aquarium who wants hang-on installation instead of a canister. The flow knob helps at feeding time. Those who need near-silent operation, or who run a much smaller tank, should look at a quieter or smaller model.
Pros and cons
- Adjustable flow knob
- Separate Bio-Sponge for bacteria colonization
- Bio-Falls adds oxygenation
- Works in freshwater and saltwater
- Seller says it makes some noise
- Cartridge needs monthly replacement
- Warranty details are vague
Performance notes
Water moves up the lift tube and through the double-sided cartridge, where floss traps particles and carbon removes odors and discoloration. The Bio-Sponge is independent of the first stage media, so bacterial colonies are not discarded when the cartridge is changed. The flow knob changes how fast water returns, which affects both turnover and surface agitation.
Specifications
| Brand | Penn-Plax |
|---|---|
| Model | Cascade 300 |
| Dimensions & fit | |
| Item Dimensions Lxwxh | 8.25 in H x 11.25 in W x 6.25 in D |
| Item Package Dimensions L X W X H | 11.4 x 8.7 x 6.54 inches |
| Item Weight | 0.01 Ounces |
| Size | Cascade 300 |
| Capacity & performance | |
| Tank capacity | Up to 100 gallons |
| Flow control | Adjustable knob |
| Flow Rate | 300 GPH |
| Age Range Description | All Life Stages |
| Construction & materials | |
| Color | Clear blue |
| Material | Plastic |
| Compatibility & installation | |
| Installation Type | Hang-on |
| Warranty & support | |
| Warranty Description | Warranty |
| Other details | |
| Water type | Freshwater and saltwater |
| Filtration stages | Quad: carbon, poly fiber floss, Bio-Sponge, Bio-Falls |
| Filter media | Double-sided cartridge, activated carbon and poly fiber floss |
| Cartridge change interval | Monthly (recommended) |
| Lift tube | Extendable |
| Department | Unisex-Adult |
| Directions | Follow included paper instructions. |
| Specific Uses For Product | Indoor |
| Target Audience Keyword | fish |
Frequently asked questions
Is the Penn-Plax Cascade 300 a canister filter?
No. It is a hang-on power filter that mounts on the tank, with a lift tube that draws water up through the cartridge.
Is the Penn-Plax Cascade 300 silent?
No. The description says plainly that the filter makes some noise.
Does the Penn-Plax Cascade 300 work in a saltwater tank?
Yes. The listing says it works in freshwater and saltwater aquariums.
Does the Penn-Plax Cascade 300 come with a filter cartridge?
The description mentions an included cartridge with activated carbon and poly fiber floss, and recommends replacing it monthly.