If your aquarium doesn't have an auto top-off, this is the first upgrade you should consider adding. Auto top-offs are not just a luxury for lazy people. They do much more than save you time.

When water evaporates out of your aquarium, only the water leaves. Everything else stays the same. When water evaporates, nearly every single parameter in your aquarium rises. These parameters then suddenly drop whenever you add water. These parameters include salinity, calcium, alkalinity, magnesium, ammonia, nitrite, nitrate, and more. Because stability is so important when keeping a reef aquarium, an auto top-off can be extremely beneficial for reducing fluctuations in all of these parameters.

There are many auto top-offs to choose from, but our favorite ones are the IceCap ATO EZ System and the JBJ Nano ATO Advanced Auto-Top-Off System. Do not skimp on an auto top-off. A faulty top-off can overfill your tank and lead to a wet floor. Both the IceCap ATO and the Tunze Osmolator have multiple redundant features to keep floors dry and deliver years of flawless operation.

An auto top-off is also very useful when you are out of town for a few days or longer. Having someone look after your tank is ideal, but an auto top-off is a great backup.

One last benefit is the performance of hang-on protein skimmers. Protein skimmers work best when the water level doesn't fluctuate. Sumps often have a skimmer chamber that maintains the water level, but when a skimmer hangs on the back of the tank, water-level fluctuations are problematic. Aquariums with filtration in the back of the tank, such as the Coralife BioCube, will also have fluctuating water levels without an auto top-off.

Further Reading: "A Simple Guide To Auto Top-Offs"

Most reef aquarists use carbon, and many use phosphate removers. If you pour some aquarium water into a white container and notice a tint, your water will be much clearer with carbon added. Phosphate removers remove phosphate, which fuels the growth of undesirable algae.

Media reactors allow for the most efficient use of chemical filter media. To unlock your media's full potential, you need a media reactor. Without a reactor, most of the water in your aquarium will bypass the carbon or phosphate media. Media reactors are sealed chambers that force water through chemical filtration media.

We recommend the Lifegard Aquatics Turbo Reactors for aquariums with sumps or filtration compartments and the Two Little Fishies Phosban Reactors for aquariums that need a hang-on unit.

Further Reading: "Media Reactor Overview"

UV sterilizers kill free-swimming organisms in the water column. The main reason to add a UV sterilizer to a reef aquarium is to reduce disease.

The more fish you add to your aquarium, the more money and emotion you invest in it, and the more tragic a major disease outbreak can be. In nature, disease spores spread out through the whole ocean, and fish encounter very few parasites. In an aquarium, infectious spores are recirculated again and again, making disease far more devastating than in nature. A UV sterilizer kills disease in the water column, greatly reducing the virulence of an infection. This can make a life-or-death difference for your fish.

We recommend UV sterilizers from Aqua Ultraviolet and Lifegard. Cheaper UV sterilizers are only designed to kill algae and do not effectively kill the larger disease-causing organisms.

Further Reading: "UV Sterilizer Overview"

For a successful reef aquarium, you need to add calcium and buffer so the corals can keep growing. You will also likely add other supplements to keep your corals as vibrant and colorful as possible. Dosing pumps automate these additions by precisely pumping fluid into the aquarium multiple times a day.

Dosing pumps don't just reduce the maintenance of adding supplements. They also encourage stability because the dosing is regular and at least daily. Adding supplements manually every week, which is common for reef aquarists, leads to an unstable reef system.

We recommend the CoralVue Hydros Blenny Controller. Easily schedule a dosing regimen to keep water chemistry within ideal ranges. You can automate 2-part calcium and alkalinity, Kalkwasser, and trace elements.

Further Reading: "Why Use A Dosing Pump"

LED lighting is the most popular aquarium lighting today, but T5 fluorescents still offer many advantages. T5 lighting is more diffuse than LED lighting, providing even light distribution and fewer dark spots. T5 lighting also has a broader and more diverse color spectrum, which can promote better coral color.

If you are already using a Kessil, Hydra, or EchoTech LED light, you can use them in conjunction with T5 lamps. Unfortunately, we no longer sell T5 fixtures because only a few companies manufacture them. If you do have a T5 fixture, we do carry the excellent ATI Bulbs.

If you already have a T5 fixture, you can swap your lamps for higher-quality ones to get a more attractive light color and a healthier color spectrum for your corals. Here are our recommended bulb combinations using Giesemann bulbs:

• 4 bulb T5s – (3 Actinic Blue, 1 Aquablue Coral)
• 6 bulb T5s – (4 Actinic Blue, 1 Aquablue Coral, 1 Super Purple)
• 4 bulbs supplementing halides or LEDS — (2 Actinic Blue, 2 Super Actinic)

Further Reading: "Are There Reasons To Buy Anything Other Than An LED Light For Your Aquarium?"