Many people wonder if adding fish tank salt to a freshwater aquarium is a good idea or if it should be avoided. This is often considered if fish are ill or appear to be coming down with an illness, but some people consider adding salt on a regular basis. For the purpose of this discussion, it will consider adding salt to an aquarium that houses a few rasboras, dwarf gouramis, bristlenose plecos, mollies, guppies, and perhaps a few ghost shrimp in a 30 gallon aquarium.

These fish are all considered freshwater fish. As such, they do not absolutely require added salt in their aquariums. Most treatments for seemingly ill fish recommend adding a small amount of fish tank salt as part of the treatment recimen. Aquarium salt in a freshwater fish tank helps the inhabitants fight off bacterial infections. This works because the pathogens evolved in a relatively salt-free environment and do not tolerate even minimal levels of salt.

Many aquarium experts recommend having small amounts of fish tank salt in the freshwater aquarium since, for the reason mentioned above, it aids in the prevention of bacterial and parasitic infections in freshwater fish. Alternatively, some freshwater fish are known to have low tolerance for aquarium salt. Of the fish mentioned in this hypothetical scenario, the plecostamus does not tolerate much salt.

(continued below)

API-Aquarium Salt 65oz US $4.99 Auction Ends: Tuesday Sep-07-2010 14:30:49 PDT   | Watch this Item

AQUARIUM 280 GALLONS SALT WATER REEF TANK US $1,500.00 (0 Bid) Auction Ends: Tuesday Sep-07-2010 18:19:17 PDT   | Watch this Item

SALT WATER MASTER TEST KIT 401M Aquarium Pharmaceutical US $28.47 Auction Ends: Tuesday Sep-07-2010 18:58:31 PDT   | Watch this Item

If there are any aquarium plants in the fish tank, salt should be limited because they do not thrive in the presence of too much aquarium salt! In nature though, even freshwater lakes have a base level of the ions that salt is made up of. In this regard, it is important to understand that being “salt free” is not the same as being “fresh water”. Even freshwater environments have some salt in them.

In the setup mentioned at the beginning of this post, if a fish were to become ill, one should consider adding one teaspoon of salt per week for 3 weeks. This will gradually increase the amount of fish tank salt in the aquarium to 1 teaspoon per 10 gallons (assuming it is a 30 gallon tank). A gradual approach will let the pleco and aquarium plants slowly adapt to a rise in salt. The inhabitants should be watched regularly to determine if they are not tolerating any level of salt. If they appear to be deteriorating, then a water change is called for to replace some of the salt water with fresh water.

After reaching an overall dose of 1 tsp per 10 gallons, stop adding extra salt. Only replace fish tank salt that is removed by water changes. For example, if 10 gallons are removed, replace with 1 teaspoon of salt. Adding aquarium salt to a freshwater aquarium can be a good action to consider. For a good source of aquarium salt, click here.