I’ve kept freshwater aquariums before, but saltwater aquariums? Aren’t they really difficult?”
Chris and I frequently hear comments like this from non-hobbyists as well as from freshwater aquarists who are contemplating making the saltwater switch. The prevailing impression among the uninitiated seems to be that keeping a saltwater aquarium with any degree of success demands an extraordinary level of skill and experience. But nothing could be further from the truth.
If you’ve developed the necessary skills to maintain a freshwater aquarium, there’s nothing to stop you from succeeding with a saltwater tank. Sure, you’ll need to familiarize yourself with a few new concepts and techniques—and maybe a new gadget or two—but virtually all the knowledge you’ve acquired as a freshwater fishkeeper will transfer.
So, what are some of the new techniques, materials, and equipment you’ll need to become familiar with before setting up a basic fish-only saltwater system?
The salt water itself
The most obvious is the salt water you’ll use to fill the tank initially and to replace any water removed during routine water changes (water lost to evaporation is replaced with fresh water). This is a simple matter of mixing synthetic sea salt into conditioned tap water (we recommend RO/DI water) and measuring samples with a refractometer or hydrometer until the desired salinity level is achieved.
The material known as “live rock” is another thing you’ll need to learn about that doesn’t exactly have a counterpart on the freshwater side of the hobby. Not truly alive but harboring all kinds encrusting organisms, live rock is used by most saltwater hobbyists to provide biological filtration, to create a natural reef-like structure for their livestock, and to increase the overall biodiversity of their systems.
Forget those decorative gravels so popular in freshwater fishkeeping. Calcareous materials (e.g., aragonite) of various particle sizes are the substrates of choice for saltwater systems.
The protein skimmer
While you’ll hear mention of all kinds of high-tech gizmos and gadgets used on the saltwater side of the hobby, one essential piece of equipment you may not be familiar with is the protein skimmer. This device mixes air bubbles and water in a reaction chamber to strip out dissolved organic compounds before they have a chance to decompose and pollute the water. In our opinion, this is one piece of equipment no saltwater hobbyist should be without. No other device is more helpful in maintaining the exceptional water quality that sensitive marine organisms demand.
What stays the same?
Notwithstanding these few differences, much of what you already know, do, or are using now can make the saltwater switch with you, including:
- The vital cycling process
- The principles of mechanical, biological, and chemical filtration
- Regular water testing for ammonia, nitrite, nitrate, pH, etc.
- Proper acclimation (for fish and corals) and quarantine techniques
- Regular partial water changes
- The rules of judicious stocking and feeding
- The principles of choosing compatible specimens
- Certain equipment, such as the tank and stand (unless it’s made of metal), submersible heaters and thermometers, pumps and powerheads, hang-on-back or canister power filters, etc.
Is anything on the saltwater side easier?
Believe it or not, at least one aspect of aquarium keeping is actually easier for saltwater hobbyists than it is for their freshwater counterparts—providing species-appropriate water chemistry. Whereas freshwater species can differ markedly in their requirements with respect to pH, water hardness, etc., the vast majority of marine specimens on the market are collected from coral reefs with virtually identical water parameters. All the constituents dissolved in natural sea water are present in correct proportions in any high-quality sea salt mix. All you have to do to provide the right conditions is mix the salt with conditioned tap water, aerate it, and heat it to the desired temperature.