So, I realized I need to get some numbers on here to help those who don’t think in metric to figure out how much salt to use per gallon and so on. Salt can help protect fish a little from nitrite so having 1 ppt of salt in a system during initial cycle up is a good idea if cycling with fish. Also 1-2 ppt of salt can be beneficial to many fish to help improve their slime coat and osmotic pressure. Most plants can handle 2 ppt of salt and even 3 ppt will only affect the sensitive plants like strawberries.
So here are some numbers to help people calculate how much salt would be needed for their systems.
4lb of salt per 100 gallons will give 5ppt
1000 lb of water is aprox 125 gallons
100 gallons is aprox 800 lb
1 lb of salt per 100 gallons = 1.25 ppt
1 lb of salt per 125 gallons = 1 ppt
Anyway 600 gallons and trying to get a level of 3 ppt of salt to help fish without hurting plants.
3 ppt divide by 1.25 ppt = 2.4 lb per 100 gallons to get the 3 ppt
2.4 lb salt times 6 = 14.4 lb of salt into my system to approach 3 ppt.
Now I just have to figure out how to measure out 14 lb of salt. Any ideas? (when I first wrote this, I didn’t have a kitchen scale to weight the salt.)
The salt to get is the sun dried pure water softener salt or pool salt. Generally the cheapest stuff they have. The smaller the crystals the easier it will dissolve but you really want to make sure it is not pelleted and you don’t want anything that removes iron or anything special like that. Just plain solar dehydrated sea water is what you are after.
It is important to dissolve the salt before putting it into a fish tank. If you have a sump tank with no fish in it, you may simply dump the salt in the sump. However, if you have no sump or there are fish in the sump, you will need to dissolved the salt in buckets of system water before pouring them into the system. This can take a while. If you have some means where you could run the water through a bin or bucket and let it waterfall back into the system, then tat would be much easier since the salt will sit on the bottom of the bin and having a continuous flow of less salty water will help it dissolve faster while still protecting the fish from the raw salt crystals. See the salt crystals will sit on the bottom of a tank and if a fish rests against it, they can get burned like a chemical burn.
General note here, I do not recommend salting a system on a regular basis. I grow channel catfish and they don’t like much salt so I make a point of leaving my systems unsalted except for when a health issue arises or, in the case of the quarantine system, I will salt that to 3 ppt when I get new fish. Nitrite spikes warrant salting to 1 ppt ASAP to help mitigate the nitrite toxicity to the fish. If you are cycling up a new system with fish, it would be reasonable to have that system salted to between 1-3 ppt, however if you will be doing water changes, you won’t be able to keep track of the salt level so you may wish to hold off salting until after the ammonia spike starts to go down at which point you need the salt to protect the fish from nitrite and it’s time to stop changing water anyway.