Starting Cycle Ammonia Question

[cdfjr1975]

Should I be concerned that it appears I have ammonia even though I have not introduced any? I started filling a 20g long with salt water while waiting for my refractometer so I've had it running about two weeks. The left is the salt water registering about 3 ammonia where the right is my rodi.

Tank is an old freshwater tank was cleaned with hot water and dry about a month after only fish died. Rinsed and salt added. Only same equipment is the aquaclear 70 (no media) and heater.

Thank in advance!

 

[aquanerd57]

Any new tank will run a nitrogen cycle when it's new. Are you adding rock? Dry or live? Any way now is the time to do that and get a heater. Your will cycle. If it's live rock no lights at all for eight weeks. The ammonia will skyrocket killing all critters on the rocks but preserving the valuable nitrobacker bacteria.Do a fifty percent water change at 4 weeks. And again in another 4 weeks. Keep checking changing water if necessary till you have zero ammonia. The tank is now stable for inhabitants. If your adding substrate do it with rocks. You can do it separate with rocks in a container with a lid and a power head. You want everything to cycle now before adding anyone in the tank.