A Guide to Setting Up Saltwater Aquariums (Part I)

So, you are wondering if a saltwater aquarium is for you. Most people believe that keeping a marine aquarium is infinitely more difficult than a freshwater aquarium. not so The simple truth is that saltwater fish and invertebrates are not necessarily more difficult to keep, they just have different requirements than freshwater fish and are a bit less forgiving when it comes to bugs. The key to fully understanding this is to understand the basic concepts presented here. With the excellent variety of beautiful saltwater fish to choose from, it’s no wonder so many hobbyists dream of keeping a marine aquarium.

This guide is intended to answer many of the questions a novice marine aquarist may have, and provide some basic guidelines for selecting and caring for saltwater fish and invertebrates. In addition, we hope that every saltwater hobbyist reads several good current books on the subject.

Reef Tank and Fish Tank: What is the difference?

There are many different ways to set up an aquarium depending on what you would like to keep and what interests you most in the hobby. Consequently, hobbyists tend to put names to the different types of aquariums that can be set up because they have similar general requirements depending on the classification of the tank.

fish only tank

A Fish Only Tank is a tank that is dedicated to keeping fish, without any corals, anemones or clams. They may contain some mobile invertebrates primarily to help keep the tank clean. This setup is easier to set up and less expensive than a reef tank. This type of tank can also be categorized into two different areas, fish only or live rock fish only. This type of system typically contains a large variety of species that require an extremely specialized setup. The needs of the corals or anemones take priority while the fish in these tanks are considered secondary. Although we generally classify all tanks with corals as reef tanks, there are still different types of reef tanks such as soft tanks, LPS (small stony polyps), and SPS (small stony polyps). These three tanks also have different requirements.

What is the difference between salt water and fresh water?

So what is the difference between salt water and fresh water? As mentioned above, saltwater fish are more sensitive to changes in their environment. Freshwater fish are found in rivers, streams, ponds and lakes, saltwater fish are collected from oceans and seas. As such, their natural environment is quite stable and they do not easily adapt to major changes in water chemistry or temperature. Also, since nearly all saltwater fish and invertebrates are wild-caught (many freshwater fish are raised in tanks or ponds), there are increased risks associated with handling and shipping. Risks, shipping and collection costs, and supply and demand also make saltwater specimens more expensive than their freshwater counterparts.

important factors

Important factors in a saltwater tank are pH, nitrate, salinity, and temperature. During the cycling process, ammonia and nitrite can also be a problem. These elements are no different from those in a freshwater tank, but the degree to which they can be diverted is very different. PH of a marine tank The pH of a marine tank is one of the most important factors. Marine fish and invertebrates are especially sensitive to rapid changes in their pH, so keeping pH fluctuations within 0.2 each day is very important. All sea creatures like a pH close to 8.2, which ranges from 8.0 to 8.4. pH should never drop below 8.0 Nitrates

The next important factor is nitrates. Saltwater fish are more tolerant of higher nitrates than invertebrates (in general), but they still like nitrates below 20 ppm, and most invertebrates require less than 5 ppm. Reef keepers tend to cite anything above 0.5 ppm as unacceptable, but this is an unrealistic goal for fish-only or minimal invertebrate tanks. Salinity

The next factor of concern is salinity or specific gravity. In general (very general) terms, specific gravity is the amount of salt in the water. Many aquarists treat specific gravity and salinity as the same thing, but technically speaking, they are not. Specific gravity depends on temperature and salinity does not. Most hydrometers (hydrometers measure specific gravity) are calibrated to read the correct specific gravity at 59F. Since this is a bit low for most tanks, hobby grade hydrometers are usually temperature corrected to read the correct specific gravity at or around 77F (25C).

specific gravity

In any case, most creatures will acclimate to almost any specific gravity (within reason), as long as it doesn’t vary too much. The specific gravity of a saltwater tank should be around 1.022. It is worth noting that the salinity of natural seawater varies by location (ocean, lagoons, estuaries), ranging from 1,020 to 1,030. Therefore, different fish may be native to different salinities and may need some time to acclimatize to a different salinity.

Temperature

Finally, the temperature of a saltwater tank is basically the same as that of a freshwater tank. Anywhere between 75F and 80F (24C – 27C), with 77F (25C) being a good middle ground. Wild temperature variations increase fish stress and invariably lead to disease, so a good heater (or cooler) is a must. On the other hand, submersible heaters tend to be preferred over rear hanging ones.

Also, they seem to be a bit more reliable than the less expensive ‘clip-on’ type. Other factors worth keeping an eye on are alkalinity and calcium. The alkalinity of a saltwater tank is really critical for long-term success. Without a decent alkalinity reading, the pH of the tank will drop over time and endanger the lives of your pets. The alkalinity of a saltwater tank should be between 2.5 and 3.5 meq/l. Calcium is more of a problem for reef keepers than it is for a fish-only tank. However, once you get going and want to have invertebrates, monitoring calcium levels becomes a must. Without calcium and other trace elements, invertebrates cannot properly form their exoskeletons and will not survive. Calcium levels should be 400 to 450 ppm Ca++. Some of the easiest invertebrates to keep, like shrimp, also need regular supplementation of iodine and other trace elements. Most foods will provide the necessary amounts of these elements. However, if you are using a protein skimmer, these items will be removed from the water and will need to be replaced manually.