45 Gallon Tall vs Long Comparison: What Fits Where

This 45 gallon tall vs long comparison settles a question we get weekly at Gensou Aquascaping, 5 Everton Park: “Which 45 should I buy?” Short answer — long, almost always. Long answer — below, with specs, use cases, and the one scenario where tall actually wins.

The Raw Dimensions

45 tall: 36 x 12 x 25 in (91 x 30 x 64 cm), ~170 L. 45 long: 48 x 12 x 19 in (122 x 30 x 48 cm), ~170 L. Same volume, totally different tank. The long gives you 31 cm more footprint length at the cost of 16 cm less height.

Footprint and Swimming Room

Most fish swim horizontally, not vertically. A 122 cm long tank is more visually peaceful and supports tighter schools of rummynose, cardinals or harlequin rasbora. A 91 cm tall tank with 64 cm height creates wasted water that fish rarely use beyond feeding time.

Aquascaping Layers

30 cm depth (front-to-back) is identical on both — still tight. But the long gives you more lateral composition room: you can run three islands, a clear path of view, or a classic Iwagumi triangle with two stones. The tall is forced into vertical columns and often reads as cramped. Our Iwagumi layout basics explains the math.

Lighting Reality

64 cm water column on the tall needs serious LEDs plus CO2 to grow any carpet. The long’s 48 cm column is achievable with a mid-tier Chihiros or Week Aqua unit. Electricity cost matters — the tall will draw 30-50W more per day.

Floor Load

Filled weight is roughly the same (200 kg). Both fit HDB load-bearing walls. The long’s wider footprint spreads load better, which marginally helps on older flats with timber subfloors.

Stocking Differences

Long: 20 cardinal tetras + 10 corydoras + 1 pearl gourami. You can put bottom dwellers here because they have floor space. Tall: angelfish pair, discus, dwarf gouramis — vertical swimmers that use the height. Corydoras feel trapped on tall formats. See our vertical swimmers list.

Viewing Angle

Tall tanks look good from standing distance and suit living room wall-mount setups. Long tanks look better seated on a sofa at 1.5 m distance — which is how most people actually view their tank. Our HDB aquarium placement covers sightlines.

Maintenance Ergonomics

Scraping algae off 64 cm of glass is wrist-wrecking. Long tanks let you plant and trim with shorter reaches and less shoulder strain. For hobbyists over 40, this matters.

Cost in Singapore

New 45 long rimless tanks are more common — SGD $380-$550 at C328 Clementi and Green Chapter Jurong West. 45 talls, being a niche format, often cost SGD $480-$650 because they’re imported on request. Used market on Carousell is similar: longs at SGD $180-$260, talls SGD $200-$320.

When Tall Actually Wins

Three cases. One: you have counter space only 1 m wide but ceiling room to spare (HDB corner console). Two: you want a single angelfish pair as a display. Three: you are running a tall biotope — South American flooded forest with vertical driftwood. Outside these, pick long. More context in our choosing tank footprint piece.

Singapore Sourcing Summary

C328 Clementi has both formats on weekends — 45 long SGD $420, 45 tall SGD $520. Y618 Serangoon North leans toward longs in their showroom (SGD $450). Green Chapter Jurong West carries both plus cabinet combos (SGD $680-$820). Iwarna Aquafarm sells ADA 90P at SGD $680 (close to 45 long spec). Nature Aquarium Gallery Thomson Road does custom orders in either format, from SGD $900 glass-only. Polyart stocks starphire versions occasionally. Carousell remains the best used source — check listings weekly; SGD $150-$250 for complete setups. Shopee helps with lights, filters and CO2 gear (SGD $200-$400). Stands should be ordered cut-to-size to match; load-bearing 1.2 m or 90 cm profiles cost SGD $180-$280. Budget the difference into filtration, not glass.

Related Reading

• 45 Gallon Setup Guide
• Choosing Tank Footprint
• Iwagumi Layout Basics
• Vertical Swimming Fish
• HDB Aquarium Placement