Simple Care Guide

Saltwater Aquarium Care

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Discover simple, step-by-step guides created by API® experts to help you keep your water healthy and your fish thriving. Search for specific topics or explore our categories below — from freshwater to planted tanks and ponds — to care routines, water tips, and product recommendations tailored to your setup.

Regular Care

It’s smart to be proactive! Many fish keepers and aquarium hobbyists seek to treat problems once they’ve already occurred, and in some cases, even once they’ve escalated to the point of unmanageability. This is why it’s prudent to maintain a healthy aquarium from the moment that it has been established. The result will be healthy and happy fish, and an aesthetically pleasing, tranquil aquarium.

Taking just a few minutes on a regular basis to maintain your aquarium conditions is key to a healthy underwater world.

Choose from the categories below to learn more about routine saltwater aquarium maintenance.

Cleaning Your Aquarium

When organic sludge builds up in the aquarium, it can smother the nitrifying bacteria that maintain the nitrogen cycle, creating an unhealthy environment for fish. Weekly addition of API® MARINE STRESS ZYME™ bacterial cleaner ensures a healthy population of sludge-destroying bacteria to break down any organic matter that might threaten your aquarium’s cycle. This all-natural formula contains millions of live bacteria that consume sludge and organic debris, reducing aquarium maintenance by keeping live rock, coral, sand, gravel, and aquarium glass clean. May be used weekly to reduce aquarium maintenance and maintain a strong biological filter.

MARYNE STRESS ZYME™

Controlling Algae

After starting a new saltwater aquarium or performing a filter or tank maintenance (like a water change) on an establish tank, the addition of beneficial bacteria are required to kick start the nitrogen cycle in your tank. This cycle can take two to six weeks to fully establish in a new aquarium and will be necessary for the health of your fish. Without these beneficial nitrifying bacteria, toxic ammonia quickly builds up in the aquarium and will stress the fish. The all-natural, API® MARINE QUICK START™ nitrifying bacteria formula immediately starts the nitrogen cycle, which converts toxic ammonia into nitrite, then into harmless nitrate to help prevent fish loss in your saltwater tank.

MARINE ALGAEFIX™

For Clean Clear Water

Organic waste is released into a saltwater aquarium by fish, invertebrates, algae, and uneaten fish food, all of which degrade water quality. API® BIO-CHEM ZORB™ filtration media contains a high grade resin/carbon blend for the superior removal of aquarium pollutants, including colors and odors, and it removes light-blocking impurities for improved plant growth in saltwater aquariums. This breakthrough water filtration technology is more effective than carbon alone, and is available in ready-to-use pouches or cartridges that fit most filters. Cartridges should be replaced monthly and larger pouches should be changed every two months or sooner if colors or odors are detected. Be sure to dos API MARINE QUICKSTART™ nitrifying bacteria whenever filter media is rinsed or exchanged so that the nitrogen cycle in the aquarium is maintained for the health of your fish.

BIO-CHEM ZORB™

MARINE QUICK START™

Measuring Water Parameters

Water testing is an important part of boosting and maintaining aquarium health to ensure optimal aquarium conditions. API® SALTWATER MASTER TEST KIT measures the four most important saltwater parameters – pH, ammonia, nitrite, and nitrate – to enable easy monitoring of your tank’s nitrogen cycle, and to aid in maintaining a thriving saltwater aquarium. Testing is fast, easy, and accurate, yielding precise results, and comes with four glass test tubes with snap-tight caps and a convenient holding tub for easy storage. The kit also includes a safe, step-by-step instructional booklet with a color chart that provides information on how to correct unsafe water conditions.

Another great testing kit for a saltwater aquarium with corals or reefs is the API REEF MASTER TEST KIT, which measures calcium, carbonate hardness, phosphate, and nitrate, all of which can have a significant impact on the health of your live corals. Testing is fast, easy, and accurate, yielding precise results, and comes with four glass test tubes with snap-tight caps and a convenient holding tub for easy storage. The kit includes a safe, step-by-step instructional booklet with a color chart that provides information on how to correct unsafe water conditions.

It is also possible to use API 5-IN-1 TEST STRIPS on established tanks to determine your water quality by measuring nitrite, nitrate, pH, and carbonate hardness parameters in your aquarium. For newer tanks, it is essential to test for toxic ammonia in addition and so it is recommended to use API AMMONIA TEST STRIPS to ensure that these levels are kept to a minimum. Test strips are fast, accurate, and easy to use, and include information on how to correct unsafe water conditions. Your nitrate levels can be used as a guide to determine your water exchange frequency and amounts, simply adjust your water change schedule so that your nitrate does not exceed 20ppm between water changes.

SALTWATER MASTER TEST KIT

REEF MASTER TEST KIT

5-IN-1 TEST STRIPS

AMMONIA TEST STRIPS

Caring For Corals

Essential coral care is necessary for a thriving saltwater aquarium. Since corals are living creatures, they need a variety of nutrients and their own optimal water conditions to ensure they stay healthy.

API® MARINE COMPLETE TRACE™ water treatment acts as an all-natural source of over 60 trace elements found in sea water, plus iodine. It replenishes trace element imbalances in marine and reef aquariums caused by protein skimming, as well as other natural aquarium processes. API MARINE COMPLETE TRACE water treatment maintains proper water conditions containing hard and soft corals, live rock, coralline algae, crustaceans, starfish, and saltwater fish. It should be used weekly to prevent any imbalances of the trace elements that are found in sea water.

MARINE COMPLETE TRACE™

Adding Calcium

Corals and saltwater fish are both negatively affected by a lack of calcium in your marine tank, as calcium is vital for the proper health, growth, and coloration of these in your saltwater aquarium. API MARINE CALCIUM is a natural way to increase calcium levels in your reef aquarium, and should be used whenever a calcium deficiency occurs in your water. Calcium can be monitored using the API CALCIUM TEST KIT to make sure that the calcium level is optimal for the fish or corals that are being kept in your tank.

MARINE CALCIUM

CALCIUM TEST KIT

Adding Magnesium