• 1.9 L media basket - enough room to run mechanical, biological and chemical stages at once instead of choosing two of the three
• 1500 L/h through the media, not past it - the bottom-to-top path forces every litre through the basket
• Dual flow control - front dial for output, side dial to balance surface skimming against sub-surface intake
• Telescoping intake and heater holder - draw from any depth, and keep the heater out of the display
• Self-priming pump - restarts itself after a blackout or a water change with no siphon to coax
• Blue maintenance alert with overflow protection - on a heavy waste load, media clogs faster, so being told about it matters more here than on the small models
• 350 mL of Seachem Matrix included - a starting charge for the basket
• Self-cleaning corrosion-resistant impeller - marine-safe and the only wear part

Running cost assumes continuous operation at 30c per kWh - about 5 cents a day.

The rim requirement is the one that changes at this size. The Tidal 75 needs 3.3 cm of clear trim against the 2.6 cm of the 35 and 55, and that extra 7 mm rules out some braced tanks that would take a smaller Tidal.

• 8.5 cm behind the tank - to the wall, measured from the back glass
• 3.3 cm of clear rim - check this before anything else on a braced or hooded tank
• 4.3 cm inside the tank - for the intake and return

A five-foot 150 x 45 x 45 cm tank holds roughly 300 litres and sits at the top of the Tidal 75's range. A heavily stocked four-foot tank of 200 litres is a better use of it than a lightly stocked five-foot one.

Rated volumes assume moderate stocking. Heavily stocked tanks, messy eaters and large cichlids all warrant sizing up one model.

Suitable for: freshwater and marine aquariums from roughly 180 to 300 L; goldfish, cichlid, pleco and turtle setups where waste output runs ahead of tank volume; anyone wanting three media stages in one basket.

Not suitable for: tanks with less than 3.3 cm of clear rim; rimless tanks; tanks pushed flush to a wall; quiet nano and shrimp tanks, where 1500 L/h is far more current than the stock wants.

• Tidal 75 filter
• Heater holder
• Telescoping intake pipe
• Levelling dial
• Coarse foam filter pad
• 350 mL Seachem Matrix bio-media
• Instruction manual

• A heater - the holder is supplied, the heater is not
• Chemical media such as carbon or phosphate remover
• Additional Matrix beyond the 350 mL supplied, which fills under a fifth of the 1.9 L basket

• On a heavy waste load, expect to rinse the foam more often than the manual's general advice suggests - watch the blue indicator rather than the calendar
• Rinse foam and Matrix in tank water only; tap water will kill the colony
• Matrix does not exhaust and never needs replacing
• Clean the impeller and its well every few months, sooner in hard water

Supplied for 240 V / 50 Hz Australian mains with a standard plug. Run the cord as a drip loop below the powerpoint and switch off at the wall before opening the filter. Never run the pump dry. A heater fitted to the holder must stay fully submerged at your lowest water level.

• Seachem Matrix - the 350 mL supplied barely starts a 1.9 L basket, so a litre is the sensible companion buy
• Seachem MatrixCarbon - the chemical stage the big basket has room for
• Seachem Purigen - polishes water on heavily stocked tanks where organics build fast
• Seachem Tidal Replacement Impeller - size 75, the first part to change if it goes noisy

Three years against defects in materials and workmanship, impeller excluded, extendable to five years by registering the filter with Seachem. This is in addition to your rights under the Australian Consumer Law, which cannot be excluded.

240 V / 50 Hz with a standard Australian plug. Ships as a standard parcel.

Is the Seachem Tidal 75 enough for goldfish or cichlids?

For a tank up to about 300 litres, yes - and it is the size to pick for that stock. Goldfish and large cichlids produce waste out of proportion to tank volume, which is what the 1.9 L basket is for. Above 300 litres, move to the Tidal 110.

Why does the Tidal 75 need more rim clearance than the 55?

The body is larger, so it needs 3.3 cm of clear trim rather than 2.6 cm. On braced or hooded tanks that difference decides it, so measure the rim before the tank volume.

Would two Tidal 55s be better than one Tidal 75?

Two 55s give more total flow and redundancy, but also two rim cut-outs, two lots of maintenance and 10 W instead of 7 W. On one tank, the 75's single 1.9 L basket is simpler and cheaper to run.

Can I use it on a marine tank?

Yes. The impeller is corrosion-resistant and Seachem rates the filter for freshwater and marine.

What does the Tidal 75 cost to run?

About 61 kWh a year, or roughly $18 at 30c per kWh - around 5 cents a day for continuous running.