Nitrite in tap water, killing fish?

[Mark Sperry]

Hello everyone.  I have an issue that I think has been potentially killing fish after water changes.

 

I have a 75 gallon, well-established planted tank with rainbow fish, clown loaches, and assortment of tetras.  It Is generally fairly stable. However, over the years I have noticed that occasionally after water changes I would lose a fish or two. I thought it might be temperature fluctuation or just maybe stress related to being overdue for a water change.

 

Today, I used a python water change system today for the first time. I have checked my source tap water previously and never really noticed an elevated nitrite level ..But I have not checked in a while.
 

Today, I performed a 33% water change with the python and did everything appropriately regarding adding prime (10 cc for for my 75 gallon tank) and also i kept temperature stable.  I happened to check my source tapwater and noticed that it had nitrite and nitrate as per the photo. 50 ppm nitrate and 1 ppm nitrite.. 0 ammonia.  The tank itself is showing essentially zero nitrite and 40 ppm nitrate (otherwise stable pH etc).  
 

About 30 minutes after the water change, a silver tip tetra showed signs of stress. He has swimming in the corner of the top of the tank.  I added 5 cc of additional Prime but my bigger question is what to do from here about my tap water.   I don’t want to do RO etc.   any thoughts on options for that level of nitrite in tap water?  I think it is killing my fish with water changes.   Thanks so much.
 

 

Edited October 7, 2021 by Mark Sperry

[Scapexghost]

If your tanks nitrate levels are lower than your tap, then there is little reason to change water at all l, at least not frequently. Do smaller water changes less often. Maybe 5-10% every month or two just to prevent a pH crash.

[Colu]

I agree with @Scapexghost you could do smaller water changes and I would use a double dose of prime after every water change you could prepare your water in a  tote or large bin before a water change and put a small heater to get the temperature the same as your tank and run a small  filter with seachems purigen in it to absorb any nitirte and nirates a couple of days before you do your water change

Edited October 7, 2021 by Colu

[Mark Sperry]

Thanks!   I have limited space and a large tank so I doubt a tote will work but it’s a good idea. Not sure what I will do.  Called the water company today.