Aquarium Setup Guide
UK Edition
Everything you need to plan a successful freshwater aquarium — from floor load calculations and equipment sizing through to cycling timeline and full cost breakdown by setup style.
By Adnan & Hasan, AD Aquatics specialists · Updated 2025
Tank Weight & Floor Load
The most overlooked part of aquarium planning. Water weighs 1 kg per litre — but substrate, decor, the tank glass itself, and the cabinet all add significant weight. UK domestic floors in properties built after 1945 are typically rated for 150–300 kg/m² distributed load; older properties may be lower.
The table below uses typical weight estimates for a filled, fully equipped tank on a purpose-built aquarium cabinet:
| Tank Volume | Tank Footprint | Water Weight | Tank + Equipment | Substrate (5 cm) | Cabinet | Total Weight | Floor Load (kg/m²) | Recommendation |
|---|---|---|---|---|---|---|---|---|
| 60 L | 60 × 30 cm | 60 kg | 12 kg | 5 kg | 18 kg | ~95 kg | ~528 kg/m² | Use cabinet with levelling feet; spread load |
| 100 L | 80 × 35 cm | 100 kg | 18 kg | 9 kg | 22 kg | ~149 kg | ~532 kg/m² | Place against wall; check floor joists run perpendicular |
| 150 L | 100 × 40 cm | 150 kg | 22 kg | 12 kg | 28 kg | ~212 kg | ~530 kg/m² | Loadbearing wall preferred; avoid suspended floors |
| 200 L | 100 × 50 cm | 200 kg | 28 kg | 15 kg | 35 kg | ~278 kg | ~556 kg/m² | Loadbearing wall; consider structural survey for older builds |
| 300 L | 120 × 55 cm | 300 kg | 40 kg | 20 kg | 45 kg | ~405 kg | ~612 kg/m² | Structural survey recommended; ground floor safest |
| 450 L | 150 × 60 cm | 450 kg | 60 kg | 30 kg | 60 kg | ~600 kg | ~667 kg/m² | Structural engineer required; ground floor/concrete slab only |
Note: Floor load (kg/m²) calculated over tank footprint only. Actual load per unit area depends on cabinet base design — full-base cabinets distribute load better than four-leg designs. Always place tanks on solid, level surfaces.
Nitrogen Cycle Timeline
The nitrogen cycle is the biological process that converts toxic ammonia (from fish waste) into less harmful nitrate via beneficial bacteria colonies in your filter media. Every new tank must complete this cycle before fish can be safely added.
| Week | Fishless Cycle (Ammonia) | Fish-In Cycle (Hardy Species) | Seeded Filter Cycle | Key Action |
|---|---|---|---|---|
| Week 1 | Dose ammonia to 4 ppm; Ammonia rises; no nitrite yet | Add 2–3 hardy fish (danios, mollies); Ammonia begins rising 0.5–1 ppm | Add 50% seeded media from established tank | Add bacterial starter (Tetra SafeStart, Seachem Stability). Test daily. |
| Week 2 | Nitrite appears (0.5–2 ppm); Ammonia starts dropping | Nitrite appears; 30–50% water change if ammonia >0.5 ppm | Ammonia/nitrite may spike briefly | Nitrite spike is normal — Nitrosomonas bacteria are active |
| Week 3 | Nitrite peaks (5+ ppm possible); Nitrate appears | Nitrite peaks; daily 30% water changes; no new fish | Parameters often stable by end of week 3 | Nitrobacter bacteria converting nitrite → nitrate |
| Week 4 | Nitrite dropping; Ammonia 0; Nitrate rising | Nitrite dropping; parameters stabilising | Cycle complete if seeded media was mature | Re-dose ammonia to 2 ppm; test again after 24 hrs |
| Week 5–6 | Ammonia 0 + Nitrite 0 within 24 hrs of dosing → Cycle complete | Ammonia and nitrite consistently 0; cycle complete | — | Fishless: add fish slowly over 2 weeks; Fish-in: add gradually |
Cycle complete = ammonia 0 ppm and nitrite 0 ppm within 24 hours of dosing 2–4 ppm ammonia. Temperature between 24–28°C accelerates bacterial growth. pH below 7.0 significantly slows the cycle. See our Aquarium Maintenance Guide for ongoing water change schedules post-cycle.
Equipment Sizing by Tank Volume
Undersizing equipment is the most common and costly mistake in aquarium setup. Use this table as a baseline — heavily stocked tanks or species with high bioloads (cichlids, goldfish, large predators) should target the upper end of each range.
| Tank Volume | Filter Turnover (l/h) | Heater Wattage | Lighting (planted) | Lighting (fish only) | CO₂ (planted) |
|---|---|---|---|---|---|
| 60 L | 300–480 l/h | 100–150 W | 24–36 W LED / 0.4–0.6 W/L | 12–18 W LED | Mini pressurised or Fluval 88g |
| 100 L | 500–800 l/h | 150–200 W | 40–60 W LED / 0.4–0.6 W/L | 20–30 W LED | 0.5 kg bottle + regulator |
| 150 L | 750–1,200 l/h | 200–250 W | 60–90 W LED | 30–45 W LED | 0.5–1 kg bottle + regulator |
| 200 L | 1,000–1,600 l/h | 250–300 W | 80–120 W LED | 40–60 W LED | 1 kg bottle + dual-stage regulator |
| 300 L | 1,500–2,400 l/h | 300–400 W (×2 heaters) | 120–180 W LED | 60–90 W LED | 2 kg bottle + dual-stage regulator |
| 450 L | 2,250–3,600 l/h | 2× 300 W heaters | 180–270 W LED | 90–135 W LED | 2–4 kg bottle or CO₂ system |
Filter turnover = 5–8× tank volume per hour for community tanks; 8–10× for cichlids/goldfish. Use two smaller filters rather than one large filter for redundancy on tanks over 200 litres. Heater wattage assumes UK ambient temperature of 18–22°C.
Setup Cost Breakdown by Style
Costs below reflect typical UK market pricing for quality (not entry-level) equipment. Professional installation by AD Aquatics includes all equipment, hardscape, stock and a full handover — see our complete setup packages for inclusive pricing.
| Component | General Community | Planted Aquascape | Cichlid System | Discus Planted | Rock Formation |
|---|---|---|---|---|---|
| Tank + cabinet | £120–£250 | £150–£350 | £150–£350 | £200–£450 | £150–£350 |
| Filter | £50–£120 | £80–£180 | £80–£200 | £120–£280 | £80–£200 |
| Heater | £20–£45 | £25–£60 | £25–£60 | £40–£90 | £25–£60 |
| Lighting | £30–£80 | £80–£220 | £40–£100 | £120–£300 | £60–£150 |
| CO₂ system | — | £80–£200 | — | £100–£250 | — |
| Substrate | £20–£50 | £40–£120 | £25–£60 | £60–£150 | £30–£80 |
| Hardscape (rock/wood) | £20–£60 | £60–£200 | £60–£180 | £100–£350 | £120–£400 |
| Plants | £20–£50 | £80–£250 | £0–£30 | £120–£350 | £0–£30 |
| Fish stock | £40–£120 | £30–£80 | £60–£150 | £100–£400 | £60–£150 |
| Test kits + treatments | £30–£60 | £35–£70 | £35–£70 | £40–£80 | £35–£70 |
| DIY Total | £350–£835 | £630–£1,730 | £475–£1,200 | £1,000–£2,700 | £560–£1,490 |
| AD Aquatics Installed | from £650 | from £850 | from £650 | from £1,650 | from £1,250 |
AD Aquatics installed price includes professional installation, full handover, first month's water quality support, and all equipment. DIY costs exclude labour, specialist tool hire, and the cost of beginner mistakes — incorrectly cycled tanks can result in fish loss and restarting costs.
Placement Checklist
- Away from windows — direct sunlight causes temperature swings and accelerates algae growth
- Avoid external walls in winter — cold wall surfaces cool water and stress fish
- Level surface — even a 2 mm deviation in a 100-litre tank creates uneven stress across glass seams
- Near a floor drain or utility sink — water changes are weekly; proximity matters
- Power sockets — you need at least 3 sockets (filter, heater, light), ideally on a RCD-protected circuit
- Floor joist direction — where possible, orient a long tank across multiple joists rather than parallel to one joist
- Above 90 cm high — maintenance becomes difficult; most cabinets place the tank rim at 80–90 cm
Frequently Asked Questions
How long does the nitrogen cycle take?
A fishless ammonia cycle typically takes 4–6 weeks. Using a bacterial starter product can shorten this to 2–3 weeks. Fish-in cycling takes 6–8 weeks with hardy species and frequent water changes. See our cycle timeline table above for week-by-week expectations.
What floor load does a fish tank need?
UK domestic floors are typically rated for 150–300 kg/m². A 200-litre tank with cabinet weighs approximately 280 kg — over its 100×50 cm footprint that is ~560 kg/m², exceeding typical ratings. Place against a loadbearing wall and consult a structural engineer for tanks over 200 litres on suspended timber floors.
What filter turnover rate do I need?
Community tanks: 4–6× tank volume per hour. Cichlids/goldfish: 8–10× TVH. Planted tanks: 3–5× TVH (higher flow disrupts CO₂). For a 200-litre community tank, target a filter rated 800–1,200 l/h. Always run two filters if possible — redundancy is critical for large setups.
How much does it cost to set up a fish tank in the UK?
A basic 60-litre community setup costs £200–£400 for quality (not entry-level) equipment. A 200-litre cichlid or planted system runs £600–£1,400 DIY. Professional installation by AD Aquatics starts from £650 for a complete cichlid or general community setup, including fish, hardscape and handover.
Do I need RO water for a freshwater aquarium?
Depends entirely on your local water supply and target species. Most UK tap water (pH 7–8, GH 10–25°dH) suits cichlids and community fish perfectly without treatment. Softwater species (discus, cardinal tetras, rasboras) need RO or very soft tap water. See our UK tap water hardness guide for regional data and RO mixing ratios by species.
Want a professionally installed aquarium?
AD Aquatics handles everything — tank, equipment, hardscape, fish and full setup. Complete packages from £650.