Reject Water for Freshwater Aquariums?

[RW09903]

I just moved my reef tank from Bowie to Crofton last weekend. During the process, I made RO water from both locatins to help with the move. Out of curiosity, I evaluated the TDS in and out from both locations. Bowie - 138 ppm, 0 ppm out. Crofton - 40 ppm in, 0 ppm out. Would it be safe to say my reject water in Crofton is still better than straight from the tap water in Bowie?

[Jon Lazar]

Keep in mind your reject water will still have undesirables like ammonia.

[zygote2k]

reject water is good for laundry

[ScooterTDI]

I've used reject water with 200+ ppm TDS to raise a couple hundred German blue rams (which generally prefer soft water). I think you will be fine using it in a freshwater aquarium unless you are keeping maybe discus or caridina shrimp.

[madweazl]

reject water is good for laundry

This is what we use it for as well but our TDS on the input side is typically only 0-2 to begin with

[RW09903]

I've used reject water with 200+ ppm TDS to raise a couple hundred German blue rams (which generally prefer soft water). I think you will be fine using it in a freshwater aquarium unless you are keeping maybe discus or caridina shrimp.

Keeping discus and rams...

[RW09903]

Keep in mind your reject water will still have undesirables like ammonia.

Would Prime work as declorinator and ammonia reducer?

[ScooterTDI]

Keeping discus and rams...

If your reject water is 40 ppm, you'll probably be just fine with discus and rams. You shouldn't need Prime for a dechlorinator since the RO prefilters remove chlorine/chloramine. It's possible for ammonia to be produced as a breakdown product of chloramine, but I didn't use Prime when raising GBR fry and I was doing 50% water changes twice a day so they were exposed to lots of untreated RO waste.