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pH at 7.75, Low alkalinity, Low Calcium, High Salinity

Of course...1.025. 2 cups of red sea coral pro = 1.025[/QUOTE]

You are not understand what I'm saying. In this thread, I mentioned earlier that I do check when I'm mixing and its read at 1.025. And I check the tank few hours later after the water changed. Adding 2 cups of salt just happened to be at 1.025. I would be crazy to think that the bucket said 2 cups gets me 1.025 and I would just add the 2 cups and not check it with the refractometer

No I do not understand...what I can say is calibrate your refractometer the way Downbeach stated earlier and be more on top of evaporation/top off with ro/di. I really doubt 2 part would affect sp gravity to that degree without nuking all your inhabitants. The alk swings you are now creating will only further harm your corals. Good luck.
 
My tank was steady at 1.027 for a while, last time it read 1.027 was last saturday after my 10% water change. I checked on monday, it was reading 1.030. I'm doing a 20% water change today. See if that makes a different.

What did you do Monday when you noticed it was .030?
 
Of course...1.025. 2 cups of red sea coral pro = 1.025

You are not understand what I'm saying. In this thread, I mentioned earlier that I do check when I'm mixing and its read at 1.025. And I check the tank few hours later after the water changed. Adding 2 cups of salt just happened to be at 1.025. I would be crazy to think that the bucket said 2 cups gets me 1.025 and I would just add the 2 cups and not check it with the refractometer

No I do not understand...what I can say is calibrate your refractometer the way Downbeach stated earlier and be more on top of evaporation/top off with ro/di. I really doubt 2 part would affect sp gravity to that degree without nuking all your inhabitants. The alk swings you are now creating will only further harm your corals. Good luck.

+1, 2 part will not make a noticeable change to salinity, unless you add WAY to much, but at that point all of your corals would be dead.
 
What did you do Monday when you noticed it was .030?

I have a mark in the sump where water usually sit after a water change, so I just fill up to the mark again with ro/di and I stopped dosing the 1/2 dose of the 2 part that i usually do.

After I did a 20% water change today. I'm getting around 1.027 currently. I haven't check cal and alk yet. The calibration fluid for the refractometer is coming tomorrow in the mail. Let see what happen.
 
Here it is...I got my calibration solution today and it's reading sg 40. 5 above what it should be. I also checked my cal (450) and alk (8.1), so everything is alright now. But my ro/di is reading below 0 sg on my refractometer.
 
For our preferred range we want it as accurate as possible at 1.026 using the fluid. This will make testing rodi differ from zero, that is very normal. So after all you were close to 1.026 right?
 

redfishbluefish

Officer Emeritus
Officer Emeritus
Here it is...I got my calibration solution today and it's reading sg 40. 5 above what it should be. I also checked my cal (450) and alk (8.1), so everything is alright now. But my ro/di is reading below 0 sg on my refractometer.


I am compelled to clarify because I believe you are confusing specific gravity (SG) with parts per thousand (PPT) and am not sure if you actually have calibrated your refractometer. A number of the refractometers we use have both scales. We want to target SG of around 1.026, while equals approximately 35 ppt. I believe the number you refer to above is actually ppt and not sg. 40 ppt equals approximately 1.030 SG.

Back to your refractometer and calibration. You place the fluid in you refractometer and then, using a very small little screwdriver, turn the screw on top of the refractometer to make the meter read 1.026 sg (35ppt). It's now calibrated. When using single point calibration instruments, you are better off using calibration standards closest to what you wish to measure.

Hope this helps.
 
Also make sure you rinse the lenses between use with rodi, always use the same. light to view it, and that the room where it is stored does not change more than a few degrees. Room temperature changes of more than a few degrees will require most to be recalibrated.
 
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