The tank itself
- Tank, and a cabinet or stand strong enough to hold it
- A reef-capable light, with its mount
- Return or circulation pump
- Extra flow in the display if you need it
- A heater with proper control, and a backup plan
- Filter media and holders that fit your tank
- A protein skimmer, only if your plan needs one
Making saltwater
- An RODI unit, or another reliable source of clean water
- Food-safe containers for storing and mixing
- A dedicated mixing pump, and a heater if needed
- A refractometer or other salinity meter
- The right calibration fluid for your meter
- Salt, and a consistent way to measure it
Testing and maintenance
- Test kits for the parameters you’ll actually track
- A thermometer that doesn’t rely on the heater’s dial
- An algae scraper and cleaning tools used only for the tank
- A siphon or hose, towels and a plan for spills
- Replacement filter floss, socks and other consumables
- A maintenance log or calendar (Reef Companion is free)
Electrics and emergencies
- Drip loops on every cable, and sockets kept away from splashes
- RCD protection and properly rated extension leads
- Labelled cables, and equipment mounted somewhere dry
- A spare or emergency heater suited to your tank
- A plan for power cuts and pumps stopping
- Model numbers, receipts and warranty details saved
Five checks people forget
- Will the skimmer, auto top-off sensor and media basket fit the actual chamber and water depth?
- Can you get the largest piece of equipment out of the cabinet without taking the plumbing apart?
- Will the return pump still give useful flow at your tank’s head height?
- Are the plug, voltage, warranty route and spare parts right for the UK?
- Can the cabinet, and your floor, safely carry the filled tank?
Turn the list into a budget
Use the reef tank cost planner to price each section, the electricity calculator for running costs, and our reef tank kit comparison to see what three of today’s tanks include. Once you’re up and running, the free Reef Companion keeps your maintenance and spending on track.
THE SHORT ANSWER
Buy your equipment in the right order
A reef needs a safe tank and stand, temperature control, a way to make saltwater, circulation, suitable lighting, a salinity meter, test kits and a maintenance plan. Skimmers, dosing pumps, controllers and other upgrades depend on your livestock, how you remove nutrients and what your tank actually uses; they aren’t essential on day one.
The most useful checklist splits things into what you need before water goes in, what you need before livestock, ongoing consumables, and optional extras that solve specific problems. That order stops your money getting tied up in exciting equipment while a basic essential, like RODI water, a backup heater, test reagents or safe electrics, goes unfunded.
STEP BY STEP
How to do it
- 01
Decide on your tank and livestock
Settle the real volume, the layout and the broad type of livestock first. They decide your lighting, flow, heating, filtration and testing needs.
- 02
Sort out water and temperature
Plan your RODI water (or another reliable source), mixing containers, salt, salinity calibration and a properly controlled heater before you start cycling.
- 03
Add circulation and testing
Treat return flow and display flow separately, make sure there’s surface movement, and get the tests you need for cycling and your planned livestock.
- 04
Hold off on the extras
Only add a skimmer, doser, controller or reactor when your tank’s design or your test results give it a clear job, and you’ve budgeted to run it.
YOUR SITUATION
What to do in your situation
Tank support, no leaks, electrics, heater, water source and circulation
Do a dry run and test what happens when the power goes off before making saltwater.
Proof the tank has cycled, stable salinity and temperature, suitable light and flow, and testing
Only add livestock when you can measure and maintain the conditions it needs.
Rising nutrients, daily element use or repeated manual work
Choose the simplest equipment that solves the problem you’ve measured.
COMMON MISTAKES
Mistakes to avoid
Buying every upgrade at once
Automation you don’t use yet adds cost and more things to go wrong, before your tank has shown you what it needs.
Forgetting the small stuff
Extension leads, drip loops, thermometers, calibration fluid, buckets, tubing and cleaning tools can hold up your build.
No plan for replacements
A failed heater or return pump is an emergency. Note compatible spares and local suppliers before it happens.
WORKED EXAMPLE
A staged checklist for a 90-litre all-in-one
Stage one covers the tank, a level stand, a heater, a source of RODI water, salt, a mixing container and pump, a refractometer with calibration fluid, return circulation and a safe electrical layout. Stage two adds cycling tests, a light and wavemaker suited to the planned livestock, cleaning tools and a quarantine plan.
The skimmer and doser stay off the launch list. If nutrient tests later show that water changes and filter media aren’t enough, a skimmer that fits the chamber can be considered. Dosing only starts once repeated alkalinity tests show steady daily use.
BEFORE YOU CHANGE ANYTHING
Write down where you’re starting from
Note the date, the equipment or product you’re using, how you measured and the conditions behind every important number. Say whether a volume is the tank’s label figure or your real net water; whether a flow is the box rating or what actually comes out; and, for test results, the salinity, test kit and time of day. A precise-looking number is useless once you’ve forgotten where it came from.
Change one thing at a time, and decide in advance what improvement will look like: a steady test trend, less detritus, a more stable temperature, a quieter tank or a lower running cost. One reading, or one good day, isn’t a trend, and a setting copied from someone else’s tank isn’t proof it suits yours. The free Reef Companion keeps your tests, maintenance and changes in one dated log, so you can see cause and effect.
MAKING CHANGES SAFELY
Protect your tank while you make the change
Take a baseline
Measure before you install equipment, change your chemistry or alter your routine. Take photos if placement matters, and note how your livestock behaves. Without a starting point, you can’t be sure what caused any difference later.
Start small
Begin with a cautious setting or dose, and keep a way back. Hang on to the old equipment until the new one has proved itself, keep your previous schedule, and don’t add livestock at the same time as a big lighting, flow or chemistry change.
Give it the right amount of time
Mechanical problems show up straight away; nutrient and coral responses can take days or weeks. Judge the change over a sensible period, but stop immediately if you see animals in distress, a leak, overheating or an electrical risk.
Afterwards, note the result and decide whether to keep, adjust or undo the change. If the result is unclear, go back to your last stable setup and measure better, rather than piling on another change.
SIX MONTHS ON
Check it’s still the right decision
What made sense on day one can stop working as livestock grows, the room warms up, equipment gets dirty or a routine turns out to be unrealistic. Set a reminder to review it in six months, comparing what you assumed with the reality: water volume, electricity, consumables, noise, cleaning time and test trends.
Test trends, real flow, temperature, light coverage or whatever the change was for
Is it still doing its job, with room to spare?
How often you clean it, how hard it is to reach, calibration drift and missed tasks
Can you keep this up without cutting corners?
Electricity, reagents, filters, spare parts, warranty and downtime
Would you make the same choice knowing the real cost?
If it’s working, you don’t need to replace it; the review simply gives you a reason to keep it, tune it or plan an upgrade before something fails.
KNOW THE LIMITS
When to get expert help
Get product-specific or professional help for anything involving floor loading, household electrics, unsafe plumbing, damaged glass, unexplained livestock deaths, or chemistry you can’t measure reliably. Use a qualified electrician for fixed wiring, and always follow the current safety instructions for your tank, equipment and additives. Never work around damaged cables, swollen batteries, leaking seals or equipment that keeps tripping the electrics.
Your livestock’s needs can also outweigh general equipment advice. Check adult size, behaviour, disease risk and each species’ light, flow and feeding needs with reputable care guides before you buy. This guide explains the equipment decision; it can’t guarantee the result for every animal or tank.
COMMON QUESTIONS
Frequently asked questions
Do I need a protein skimmer from day one?
Not always. Your tank’s layout, stocking and how you plan to remove nutrients decide. Some tanks benefit early; others can wait.
Which equipment should I keep a spare of?
Anything whose failure quickly threatens temperature or circulation, plus cheap consumables that would stop you doing maintenance.
Can I use tap water?
RODI gives you a far more controlled starting point. Tap water varies, so test it and understand it rather than assuming it’s safe.
Check equipment will fit, and you can service it, before you buy →