refractometer help!

flutterpower

New member
Hi have had a reef tank for 12 months and it's been great but a few days ago everything died within an hour. The guy at my local fish shop told me to buy a refractometer which i have but it is measuring in % How do I concert this to SG please?
 
I've never seen a refractometer give a percentage reading. It should have a scale on the left hand side that gives you a reading. Your salinity should be around 1.025.
 
And on the right it should have the PPT, aim for close to 35 if you have corals.
PPT is parts/thousand, 35 is 3.5%.
 
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You need to check that refrac against a known 35ppt standard in this case. Since it is measuring probably brix, the reading won't be quite right for salinity. Check with a good standard and set that to read at whatever line or number you choose. Then make your saltwater to match that.
 
Did you buy the correct refractometer?
There are many different types.
just which did you get?
 
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