Salinity Issues

OriolesRock100

New Member
Hi, I'm having salinity issues and need help fixing it. I have a 120 gallon tank, and currently there is only 1 fish in it, and that is all (I'm sorry I can't remember what species he is we got him at least 6-7 years ago). He is gray and between 2-3 inches long. He is doing quite well, but I plan on adding some roommates for him and a snail cleaner crew since his most recent tankmates (a skunk clownfish and a starfish who both lived a long time) died about a year ago.

Before I go to get these fish, I wanted to do water tests to make sure everything in order. pH, nitrates, ammonia, etc etc all were fine. However, salinity wasnt wasn't. Not that I had been busy with college applications previously, so wasn't very good about checking salinity often. Anyways, I checked the SG about a week and a half ago and it was at 1.050. I double checked it, and yes, the refractormeter was and still is seemingly calibrated. Obviously this is very high so I've been adding only freshwater since. In about 11 days the SG has only dropped to 1.047 (at this point I've probably added ~4 gallons of fresh water. I'm not really sure what else to do, since this could take months to get in order at this rate. I don't want to cause any shock to the fish; he is acting completely normal - acting extremely energetic and acting happily when I go near the tank - so there isn't much of an emergency or any sort of urgency. I just want to know how I can safely lower the SG without harming the fish or taking months that I don't have to get this sorted out.

Thanks in advance for taking the time to help!
- OriolesRock100
 

lmforbis

Well-Known Member
You don’t want to drop the salinity too fast. If you can I’d drain maybe 20% of the total volume. Over the next week gradually fill it back up with RODI water checking the salinity every day. You will probably need to do this a couple times. When salinity is correct fill it up with salinity matched salt water.
 
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