Keeping Reefs Healthy

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Everyone loves to gaze into a beautiful reef tank full of dazzling fish, spectacularly colored corals and other fascinating invertebrates.

To many aquarists, keeping a reef tank is the ultimate level of the hobby. The endeavor is both very challenging and very rewarding. One of the biggest challenges is actually just staying on top of the monitoring and maintenance of the tank.

Marine aquarium expert and author of, The Simple Guide to Mini-Reef Aquariums, Jeff Kurtz, emphasizes the importance of “staying vigilant in the long term against small, subtle shifts in water quality and chemistry that, if not caught and remedied promptly, can lead to major issues down the road, such as an outbreak of hair algae or cyanobacteria.”

“This downward spiral tends to develop when I get lazy about water testing or start to allow more and more time between water changes and other maintenance,” Kurtz said. “Once the water quality balance tips, it can be a long slog back to a healthy system.”

Regular water changes (most experts recommend changing 10 percent of the water weekly) and maintenance are important, but there are additional ways to keep a tank healthy. Many reef hobbyists employ various additives or supplements to maintain healthy water chemistry.

Tim Plafcan, senior brand manager, water care, at United Pet Group, estimates that more than half, and perhaps as much as 75 percent, of all reef keepers use some kind of supplementation in their tanks.

These can include calcium and other mineral supplements, buffers, beneficial bacteria and algae control.

Additives can be liquid or dry. Some types of equipment, such as calcium reactors, essentially function like supplements. Calcium is of particular concern because it is vital for the health of corals, coralline algae and clams.

“Most of the [additives and supplements] are targeted for reef aquariums with stony corals that use calcium to build their skeletal structure,” Plafcan said.

Kurtz elaborated on this by adding, “Mineral supplementation can be extremely important for reef systems. I’ve had success by supplementing only calcium and alkalinity. Most reef hobbyists will need to supplement at least these elements, especially if their systems have a high calcium and/or alkalinity demand, such as those housing predominantly small-polyp stony corals or tridacnid clams.”

Products such as Absorptol from Acurel provide fish faster, more effective delivery and absorption of vitamins, nutrients, medications and supplements. Adding Absorptol to the tank before administering any treatments to control parasites, bacteria or fungus, may result in greater success and shorter healing time for the fish.

According to the manufacturer, Absorptol is safe for all fresh and saltwater fish, invertebrates and plants.

Perfect Balance

One issue with supplements is that there is a chance of overdosing the tank. Plafcan attributes this mainly to hobbyists not testing their water quality. Without proper testing the reef keeper does not know how much calcium, magnesium, or other substances are in the tank.

If they go ahead and add supplements, there is a real danger of adding too much of a good thing. This can harm the tank inhabitants and possibly lead to mineral deposits forming within the filter, pumps and other equipment.

Overdosing can also happen when the hobbyist is adding several different supplements.

“Products like Instant Ocean Reef Accelerator eliminate the guesswork and probability of overdosing with an all-in-one approach that has been scientifically formulated to replenish minerals based on average depletion rates,” Plafcan said.

Of course, each reef tank is slightly different, so it’s up to the hobbyist to know their tank. He recommends store owners suggest “regular water testing to verify calcium depletion rates and ensure you are maintaining optimal levels.”

Kurtz agrees that regular testing is the key for success.

“Reef keepers should be testing for salinity/specific gravity, ammonia, nitrite, nitrate, phosphate, calcium, magnesium, pH and alkalinity,” Kurtz said.

All of these parameters are crucial for the tank inhabitants.

Natural Keys to Success

Reef keepers can be successful without using additives.

“In fact, more and more reef hobbyists are relying on frequent water changes with reef-specific synthetic salt like Instant Ocean Reef Crystals,” Plafcan said.

Instant Ocean Reef Crystals or another good-quality reef salt maintains the necessary levels of calcium, other minerals, and alkalinity, all of which otherwise decline over time.

Algae control is a major concern for many reef hobbyists. While there are supplements that can help control or eliminate algae—mainly by removing phosphates or nitrates from the water—Kurtz believes the best method is preventing problem algae from appearing in the first place.

Prevention “requires a multipronged approach consisting of minimum nutrient import (conscientious live stocking and feeding), maximum nutrient export (copious water changes, vigorous protein skimming), and potentially the addition of reef-safe herbivores to the system,” Kurtz said.

Some reef-safe herbivores useful for controlling algae include nerite snails, trochus snails, turbo snails, sea urchins, yellow tangs, purple tangs, rabbitfish and some species of hermit crabs, such as the blue-legged.

Additionally, using reverse osmosis/deionized water instead of tap water for water changes prevents introducing any substances that promote algae growth, such as phosphates and nitrates.

Hobbyists often purchase RO/DI filter systems, but these can be expensive.

Some aquarium stores will sell RO/DI water to their customers, a service many reef customers are sure to appreciate.