Planning a System

Before any equipment is chosen, the plan answers two questions: what's this system for, and what will live in it? A display, a breeding system, a holding system for animals waiting to move, and a system for treating sick animals all need different things. That's the husbandry goal.

Next comes the intended livestock: the animals the system is planned for. Their needs set the light, flow, temperature, food and water quality the system must provide. Only then are the tank and equipment picked to meet those needs.

Planning the other way round, buying equipment first and choosing animals later, often ends with animals that don't suit the system, or equipment that has to be replaced. Changing direction partway costs time and money.

For every animal on the plan, find out what it needs: temperature, salinity, light, flow, food and how it's fed, water quality, and space. Behavior matters too: how big it grows, whether it fights, and what it eats besides the food it's given.

Corals differ a lot. As one example, many large-polyped stony corals come from deeper water and don't need light as intense as some other corals. Some corals need regular feeding, and too much food can pollute the water and feed pests. Module 24 covers choosing animals in detail.

If a need can't be found out, the animal isn't ready to be planned for. Ask, look it up, and report it if the answer isn't clear.

Every animal in a system lives with the same water. So for each need, look for the range that suits all of them. If two animals have no shared range for even one need, they don't belong in the same system.

Check all the needs, not just one. Two corals may want the same temperature but very different light. A fish may suit the water but eat the corals or invertebrates it would share the tank with. Some corals are aggressive and need space from their neighbors.

When needs only just overlap, every animal is near the edge of its range. Small swings then push one of them outside it. A wider shared range gives more room for error.

A mixed system keeps many kinds of animals together, for example soft, large-polyped and small-polyped corals with fish. Its conditions are a compromise between all their needs. Mixed reefs are often called the hardest kind to set up and keep going long-term.

A specialized system is built around one kind of animal, or a few with similar needs. Its light, flow, food and water can be set for those animals. Fewer needs have to be matched, so there are fewer conflicts.

Neither is wrong. The husbandry goal decides. A breeding or holding system is usually specialized; a display may be either. Once the choice is made, stick with it: switching direction later is expensive.

It starts with high-quality live rock from the ocean. The rock isn't cured; it's shipped in water, arrives within about 24 hours of being shipped, and goes into the system quickly. New high-quality live rock is added about every one to two years.

Alongside the rock: feed a variety of foods of different particle sizes (often given in microns), dose beneficial bacteria with a product such as MicroBacter7 or similar, and support every level of the food web. That includes dosing live plankton: rotifers and several kinds of phytoplankton in different micron sizes, along with a variety of other foods.

In his experience, this has produced reef systems that stand out from the rest of the hobby: living plankton, many kinds of animals spawning and reproducing, and a very high level of biodiversity. It takes about two years for a system to become very stable and mature, with a vibrant microbiome and food web (Module 9).

He wouldn't build a reef system without high-quality live rock from the ocean. The exception is a system built for another job, such as breeding or holding fish. In his opinion, starting a reef system from dry rock is a mistake.

New live rock can still bring die-off, and a lot of die-off can cause water quality problems. Test, watch, and report it (Module 9).

A quarantine system holds new animals apart before they join a display, so pests and disease can be found first. It has its own equipment. Fish and corals are best quarantined separately, because medicines used for fish can harm corals. Module 23 covers quarantine in detail.

A hospital system is for animals that get sick after they're already in a system. It's kept simple, often with no sand or rock, because medicines can harm the bacteria living on them. It relies on water changes and filtration instead.

An acclimation system is where new arrivals are adjusted to the water they'll live in (Module 25). A propagation system grows pieces cut from corals into new colonies (Module 34). Plan the space, power and equipment for each one from the start; they're hard to squeeze in later.

A tank's listed volume comes from its outside size. The water it really holds is less: the glass takes space, the water stops below the top, and overflows, rock, sand, pumps, heaters and the animals themselves take up room. In one measured example, the real volume was about 15% less than the listed one.

The sump, pipes and reactors add water. The operating volume is all the water actually in the system when it's running. Dosing, medicine and water change amounts are worked out from the operating volume (Module 35), so a wrong volume makes every one of them wrong.

The operating volume can be measured, for example by adding a known amount of salt to fresh water in the system and measuring how much the salinity rises. It also changes as rock, sand and animals are added.

When the return pump stops, water drains back from the display into the sump. The sump must have room for that drain-down water on top of its normal level, or it overflows onto the floor. Module 12 covers how to work out the drain-down and set safe water levels.

Plan the space around the sump as well. Staff need to reach every piece of equipment, clean it, and lift it out without taking other things apart. A sump crammed into a cabinet with no room to work makes every job slower, and jobs that are hard to do get skipped.

Check that the equipment the plan needs will actually fit in the sump, with room to reach it. Module 10 covers access and installation.

The carrying capacity is how much life a system can support. The animals, and the food they're given, add waste. The system removes it with bacteria, skimming and water changes, and supplies oxygen. If more waste goes in than comes out, the water gets worse.

No simple rule, such as a set length of fish per volume of water, gives a safe number for every system. It depends on the animals, their adult size, how much they eat, how they behave, and how much the system can remove. Plan by the adult size, not the size on arrival.

Stock below the limit, not at it. A system near its limit has no room to handle a missed water change, a death or a broken pump. The tests show when a system is getting close: rising nutrients or falling oxygen.

Start-up costs include the tank, stand, sump, pumps, lights, heaters, rock, sand, animals and spare equipment. Running costs come every month: electricity, salt, purified water, test kits, filter media, food and parts that wear out.

Running costs add up over the life of the system and often pass the start-up cost. A cheaper piece of equipment can cost more over time if it uses more power or fails sooner. Plan both, and plan for replacements.

Time is a running cost too. A plan that can't be paid for, or run, every month will fail even if it could be built.

Every system needs daily, weekly and longer jobs (Module 32). Count the time each one takes and decide who does it. A plan with more work than there are hours for leaves jobs undone, and undone jobs show up later as problems.

Before choosing equipment, check that it can be bought locally, that spare parts are available, and that someone can support it if it fails. Equipment that has to be imported can mean weeks without it after a failure.

Keep spares on hand for the equipment the animals can't live without for long, such as pumps and heaters. Using the same models across systems means fewer kinds of spares to keep.

Write down each piece of equipment, where it came from, and where its spares and manuals are. Report any piece that has no spare or no local support.

Corals grow from small pieces into colonies, and fish grow to adult size. Space corals so the colonies they'll become don't touch; some corals are aggressive and damage neighbors they reach. Plan fish by their adult size.

As animals grow, the load on the system grows with them: more waste, more food, more use of calcium and alkalinity. The plan needs room in filtration, light and dosing for the system as it will be, not just as it starts.

Think about future needs too: more systems, more animals, or a bigger display. Leaving space, power and plumbing for later is far easier than adding them to a full room.

For each parameter, the plan sets a target, an acceptable range around it, and call limits outside which staff act and report (Module 6). For example, alkalinity: 7.5 to 8.5 dKH preferred, call limits 6 to 10 dKH.

Targets must suit the animals in the system and be something the system can actually hold. A target the equipment and routine can't keep steady leads to constant correcting, and the swings do more harm than a slightly different but steady number (Module 6).

Write the targets and ranges down where staff can see them, so everyone works to the same numbers.

Written operating procedures describe how each routine job is done, step by step, so it's done the same way whoever does it. They make jobs repeatable and mistakes easier to find.

Contingency plans describe what to do when something goes wrong: a power cut, a heater stuck on or off, a pump that stops, a leak, a sick or dead animal. Each one says what to do first, where the spares and tools are, and who to report to. In an emergency there's no time to work it out (Module 33).

Plans are only useful if staff know them. Keep them where they can be found, and update them when the system changes.