Originally Posted by sac10918
Hmm... You make a good point. I didn't really consider the SG since I am using boxed water and I figured it would be pretty constant. The shrimp actually died before I began doing these water changes though. Actually, I am not even certain he died, I just havent seen him for like 2 weeks and he is usually pretty active. Could you explain the difference between a refractometer and a hydrometer? Is the refractometer more accurate? I have a thermometer/hydrometer that I use to check the SG and it doesnt seem that accurate. Thanks for the help!
It is super imprtant to match your parameters when doing water changes. SG in certain pre-mixed salt water (like nutri-sea i think its called?) is high...around 1.026. This isnt bad, but if YOUR tank is 1.024 say, a large swing in a short time can affect things.
Are you sure he didn molt? Sometimes they hide for a while, because their new shell is "sensitive."
A refractometer gives an accurate result in salinity, and from unit to unit are pretty much dead on. You can pretty much count on what the reading is is absolutely correct-for our purposes
Hydrometers can vary wildly. I have seen the same water measured at 1.020 with one and 1.025 with another.
The good thing, is they are usually consitent. If you can get a refractometer to borrow (many lfs will loan you one if you are a good customer), you can compare to your readings, and just adjust your readings. For example...the refractometer gives you a reading of 1.025. Your hydrometer says 1.022. You will need to measure with your hydrometer in the future and add .003
