Filters · Hang-on-back
Seachem Tidal 55
Manufacturer-rated for aquariums up to 55 US gal; needs 3 in wall clearance and fits trim up to 1 in.
HOB filter with adjustable intake and return flow, surface skimmer, heater holder, and basket media.
Consider: Needs 3 inches behind the tank and trim no thicker than 1 inch. Measure both; a wall position that fits the Tidal 35 may not fit this model.
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US version. Check what’s in the box before you buy.
Tank size Seachem rates it for
Up to 55 US gal
Choose your tank to see where it falls.
Check it against your tank →Specifications that affect fit
- Manufacturer capacity
- Up to 55 US gal
- Power
- 6 W
- Supply voltage
- 120 V / 60 Hz
- Dimensions
- 8.0625 × 6.125 × 8.375 in (L × W × H)
- Pump output
- Not published
- Filter circulation
- Not published
- Maximum flow
- 250 GPH
To see what it costs to run, enter the watts on its label and your daily hours in the electricity cost calculator.
Pump output, filter circulation and maximum flow are measured in different ways. Your filter will move less water than the box says once media and hoses are in. Measure it with the flow calculator.
Before choosing this model
- Measure wall, trim, and internal clearance.
- Check whether surface agitation and skimming suit the tank.
Our buying guides size it for these tanks:
20 gallon29 gallon40 gallon55 gallon
A filter rated for your tank can still be too tall for your cabinet or too strong for small fish: see how to choose one.
Check it against your tank → Something not working? See the troubleshooting guide.
Choose and care for mechanical, biological and chemical media before buying replacement supplies.
Included items & upkeep
- heater holder
- telescoping intake pipe
- leveling dial
- foam filter
- Matrix bio-media
- instruction manual
Plan for the routine work
- Use the alert as an inspection prompt, not a substitute for observing flow.
- Unplug before pump or impeller service.
To budget for replacement media and supplies, use the first-year cost calculator. For how often and how to clean it, follow the maker’s manual.