Backyard Aquaponics
A place to discuss aquaponics

THis is in my 6000 gallon RAS.

I've been dosing with sodium bicarb for the last week to increase the alkalinity and provide a carbon source for my Nitroacter bacteria. Everything has been slowly progressing, with nitrites slowly starting to get under control.

Salt in RAS was around 2.6ppt over the last 4-5 days. PH is in high 7's, 7.6-7.8.
Today after dosing another 8 oz of bicarb, i checked my salinity and it's now well over 4??!!

I'm not sure how to account for this except the baking soda.
I will check again in the AM, and if still over 3ppt, I'll need to do a partial water change.
I've looked up research on using sodium bicarb for PH control as well as a carbon source, and haven't seen higher salt as a byproduct. There has been no salt since Monday, when I added 50 lbs to take it from around 1,8 to 2.5.
I've added a total of 2.5 lbs baking soda since Monday.

Most salinity meters measure conductivity to determine salinity. Sodium bicarbonate increases conductivity...so you are confusing your meter by adding other stuff that changes conductivity.

Thanks. Any way to counter the false reading?

Reading this AM is back to normal...weird.

The ions will get used up, carbonate is neutralising the hydrogen ions formed during nitrification. Maybe you tested before that process had progressed very far?

Yes, that's exactly what I did. Dosed, and then checked salinity 30 minutes later. Never too chemistry. I should probably do an online course so I actually understand the "why" and "how".