Specific Gravity

I've always used the same swing bar hydrometer that i got in 2004, so this may be a bad question, but the other night i flooded my tank with RO water that dropped it from 1.025 or 6 to 1.018 and all my polpys and SPS loved it. I didnt have a check at an LFS with their spectrometer and the confirmed my readings. I'm slowly bringing it back up to at least 1.022 but do corals do better with lower SG?

 

I've always heard corals need at least 1.023 to really do well.....

 

I heard the same, and I'm very interested in how your corals liked it. I had the same problem once and everything closed up and was not happy.

 

Natural sea water is at 1.025 to 1.027. I would definitely look into getting a refractometer. Given the reaction of your coral I would say your hydrometer is way off.

 

nope. they do best at 1.023-6. maybe the were just responding to the added clean water... maybe time for a water change??

 

and get a refract or probe

 

yeah i have a refract on the way. Probably just wrong, buy I got alot of nice palys and they weren't all opening until my tank flooded lol

 

You swing arm is likely way off after 5 years of use...

 

hahaha

 

swing arms not only usually off the mark but they are inconsistent with the same batch of water which is even worse. good move getting a refract.