15 Gallon Tank Water changes with a water softener

Hello everyone, this is my first time on a forum. I've seem to have run into an issue with my tank. This tank is a fluval flex 15 gallon, good light good substrate, small co2 system and has been fully cycled for a few months now. As of maybe just over 1 month or so I installed a water softener system to our home due to the hard water staining everything. Since then I did my first water change with this new system 4 days ago, it was about a 35-40%water change. When refilling the tank my ember tetras began frantically swimming side to side, bumping the glass and gasping. (water temp was almost identical, no way there's any cross contamination, water came straight from the faucet). At that point I dimmed the lights just enough so I could monitor them, an hour later they turned extremely pale in color even a few of the pigmy corys went pale. All fish survived till morning and regained color. I assumed maybe it was too much of a water change at once. Today before going out I topped my tank off with half a gallon of water. When i arrived a few hours later the fish were pale once again! PH 6.8, AMONIA 0, NITRITE 0, NITRATE 20 as of 30 minutes ago. Could this be because of the home water softener? It uses carbon and salt to soften the water. This is the specific system "Aquasure Signature Series Complete Whole House Water Treatment System w/water softener, Water Conditioner & 75GPD RO System (64,000 Grains)" Any ideas what could be the cause? Do you think there could be a high level of sodium in my water? Should I do a 25% water change now and refill with RO water? Any ideas or suggestions is much appreciated. Thanks
-Chris

 

Hi, definitely sounds like an issue with your tap water, have you run any tests on it to see what its Gh & Kh & TDS readings are?

 

Its obvious that water as affected the fish, id hold off using that until its figured out, if you have a ro unit then I'd certainly look to reminerilse that the the right persmeters and start using that permanently, you will have more control with ro water

 

Hi, definitely sounds like an issue with your tap water, have you run any tests on it to see what its Gh & Kh & TDS readings are?

Not yet but that's what i have planned for today. I watched someone's youtube video that was in a similar predicament as me. Supposedly Sodium ions replace Calcium and Magnesium in your water. Some fish can tolerate it but others can't. Also some people have zero issue running the water softener with their aquarium.

Its obvious that water as affected the fish, id hold off using that until its figured out, if you have a ro unit then I'd certainly look to reminerilse that the the right persmeters and start using that permanently, you will have more control with ro water

I also have the option to run municipal water from the garden hose into my aquarium and bypass the softener system. the issue is the PH being 7.8. I think in combination with the driftwood Co2 and substrate ill be able to achieve a lower PH. So far everything I read from other people's experience is contradictory. Some have zero issues with the water system, others do. The only variable that changed is the water so Ill be staying away from the water system from now on. (update, this morning the fish regained all of their color)

 

If the RO system is after the water softener (like it should be) then you're effectively using RO water. Unless you have a remineralizing stage which is likely since RO water would corrode copper pipe.

 

The question you should be asking is what was the ph of your tank before you got the water softener? If you were using your hard water wouldn't it have been closer to 7.8 like the hose water? Water hardness and pH are both parameters that fish have a preference for and adapt to. If you are putting in water that has different parameters than their tank then you are stressing and potentially hurting them. If your tank pH is normally at 6.8 or has been for at least a couple weeks, and the fish in there seemed fine in it, then maybe it would be better to remineralize your soft water. If your tank is normally high pH and only dropped because of the water you added then you would want to continue adding high pH water like the hose water. Another thing to keep in mind is the temperature of the water you are adding.