Should you be adding salt to your Aquaponics system?

The short answer? You most definitely should be adding salt to your aquaponics system! Salinity is a critical health booster for the aquaculture system. However, how much should you be adding? What happens if you add too much salt to your aquaponic system? Let’s walk you through maintaining that perfect balance with your salinity.

The chemical composition of salt is made up of two types of ions, sodium ions and chloride ions.

Salt = NaCl

Chloride ions are negatively charged, while Nitrite is positively charged. In chemistry, opposites attract. Therefore, when you add salt to your aquaponics system the Nitrite and sodium bond to form Sodium nitrate. This assists in the detoxification of your system by removing excess Nitrite from the system. Consequently, when you have a nitrite spike in your system, throw in lots and lots of salt.

Additionally, the sodium ion found in salt supports the fish and their natural mechanism used to remove toxins out of their bloodstream. Salt can assist your fish in fighting off diseases and parasites as it improves its mucous skin coating.

But be careful. High salt levels will be detrimental to your plants. If your salt levels are over 2ppt, your plants will struggle. Some plants can handle higher salt levels but make sure you do your research first! Our golden range is to keep your salt levels between 1ppt and 2ppt in your aquaponics system.

You can add sea salt, aquarium salt or pool salt to your aquaponics system. 

ppt = part per thousand = kg/1000lt

Salt Weight (kg) = Total volume of system / 1000

When adding salt to your aquaponics system we recommend maintaining a salt level of 1.5ppt. Remember that your plants will begin to wilt if your salt rises to 2-2.5ppt. Exposing plants to high salt levels over long periods will cause nutrient deficiencies.

Let’s say you have a separate aquaculture setup like a quarantine tank, a hatchery or a rearing facility. Then we recommend maintaining a salt level of anywhere between 5ppt and 10ppt. High salinity is extremely important to manage fish health in standard aquaculture settings. Except for catfish as they require no salt.

So hopefully you’ll take salt a little more seriously because you should be adding salt to your aquaponics system. Make sure you do your calculations correctly and as always, observe! Check your plants for any sign of wilting. You don’t want to risk a low nutrient crop. If you have any other questions regarding salinity, please book a 15 min consultation with us, we can help you calculate your salinity levels.

Stay salty!