Reef tank contamination: What to do in an emergency

Everyone who has had an aquarium has or will have that sinking feeling when something is accidentally added to the tank. It may be an aquarium product, food or even a household cleaner. Then the panic hits. What to do? Drain the tank? Move everything to another aquarium? This is especially true with the reef aquarium. Our reef tanks are not only sensitive to water quality, they are an expensive investment. They say “failing to plan is planning to fail” so here are some tips based on real-life contamination experiences over the past 20 years.

Water Conditioners

If you are the type of person who reads and follows dosing instructions you probably add just the right amount every time. But what happens if you accidentally added a double or triple dose of water conditioner? Will it hurt corals? Will it kill my fish? No. Aquarium water conditioners contain ingredients that are very safe for the reef aquarium. Even an accidental 10-times dose will not cause disaster. Some water conditioners contain plant extracts and slime coat enhancers. The internet is full of wild stories of fish and invertebrate “suffocation” due to these slime coat products. I don’t believe any of this to be true. It’s hard to overdose or cause any problems at all with water conditioners.

 Fish and Invertebrate Foods

Aquarium foods contains nutrients like phosphorous and nitrogen. Whatever is not eaten by fish and invertebrates will be consumed by bacteria and other microscopic life. Either way some of these nutrients will be converted to ammonia, nitrite, nitrate and phosphate.  Depending on the overdose, your reef may show no ill effects or the water may go cloudy from a bacterial bloom. It is impossible to accurately predict what will happen. It depends on the composition of the food and how much is added. A slight over-feeding usually requires no action on your part. Watch the protein skimmer for gunk build-up and test the water every couple of days to make sure everything is normal. If you accidentally dump an entire bottle of liquid invert food into the tank, you’ll have to take respond with drastic measures. Dilution is the solution to pollution, so you know what that means…change water! How much water? I’d prepare for about 25%. Siphon out as much food as possible with a hose. If you have a protein skimmer, make sure it is working and be prepared to clean it several times a day. If possible, prepare a second round of saltwater so you can change water again the next day. Your reef will recover from this. You did not add a poison to the tank, you just threw off the biological balance.

 Trace Elements

Liquid trace elements, like strontium and iodine, are relatively safe. A 2-4 times overdose is nothing to worry about. Some aquarists routinely hit their reef with extra trace elements because they feel it keeps their coralline algae grow. Others, by the way, never add trace elements. If you happen to pour an entire bottle of trace elements into the tank, I would make a 20-25% water change just to dilute the elements a bit.

 pH Buffers

Reef buffers contain the same buffering ingredients that are in your saltwater mix. Reef buffers add a combination of carbonate and bicarbonate to the water. The buffer products are formulated to stabilize the pH around 8.2-8.6. Adding more buffer simply increases the buffering capacity of the aquarium, as measured with a carbonate hardness test kit. An accidental overdose is not poisonous. The undissolved powder can irritate inverts but they normally just retract for a while then return to normal. If, however, the overdose looks like a snowstorm on top of the corals…immediately blow water over the rock to remove the powder from the inverts.

 Filtration Media

What happens if your filter media gets loose in the sump or in the aquarium? Nothing. It just makes a mess. Activated carbon, phosphate removers and synthetic resins are not going to dissolve or harm anything in the aquarium. Have fun siphoning it out of the tank.

 Household Chemicals

This is a tricky issue. We’ve all been told how harmful window cleaner is to our marine aquariums. “They” make it sound like a couple of drops will cause chaos in the aquarium.  I worked with a student who wanted to test this theory. He added relatively large amounts of window cleaning products to bioassay aquariums to see what would happen. Over a five day period nothing happened to the fish or inverts. All this means is that a little spray drift, although not recommended, is not going to kill your reef. What happens if you add shower cleaner, paint thinner or mouth wash to the tank? Nothing good. Believe me, people have done it, on purpose! Let’s not get into crazy people having aquarium right now. All I can say is start making water changes if any type of household product is spilled into the aquarium.

 Human Food

More than few little kids had fed their fish a sandwich. It is gross and messy but fortunately it is not poisonous. Siphon out the particles as best you can. Watch the skimmer for foaming. Be ready to make water changes. Did you know some fish really like onions? They do! Oh, yea. I once took care of two aquariums in a friend’s pub. All week long the tanks were clear. Over the weekend, you guessed it, helpful patrons insisted in buying the tanks a beer or six.  On occasion I would find an olive floating in the tank. It never hurt anything. My biggest problem was the pub owner over-doing it with fish food!

 When in doubt, change water

As you can surmise, it is impossible to know what every foreign substance will do in a reef aquarium. There are just too many factors such as dose rate, size of the tank, and chemical make-up of the contaminant. Hopefully you will never have to deal with a seriously-harmful contamination.  A smart reef-keeper always has a couple of buckets and extra salt, just in case of emergency. You’ll never go wrong with a water change!