Should RO water have SG of 0.0?

[joeyfromlawrenceville]

Hi Guys,
I am in the middle of a hyposalinity treatment for Ich, and just received my new Refratcometer today, it is WAY DIFFERENT from the cheap plastic float needle, my SG has been almost .004 more than I thought all along. I calibrated with RO water being I have nothing else to calibrate with, would RO water be 0.0? , or am I not calibrated like I think?

PS: I will order some salt water calibration fluid soon as I can, as I know it is best for SG in the 1.023 range.
thanks,

 

[Kurt_Nelson]

The specific gravity should be 1.000, which equates to a salinity of 0.0%. I'm guessing your refractometer has both scales, one on each side. That assumes that you're dealing with actually pure (0.0 TDS) water from your RO. If the RO doesn't have a DI stage, you might not be actually at 0 TDS.

 

[joeyfromlawrenceville]

Kurt,
Yes I was reading the salinity scale ( just getting used to this thing) and I adjusted it to zero. Today I bought some distilled water and verified the calibration. I am amazed how far off the instant ocean float needle is off. I would say a refractometer is a must have and not just a nice to have item for SW aquarium, IMHO. I just wonder how much easier life will be with a digital PH gauge, instead of guessing a color match, trying to find the right light,and a good white background.
Thanks.

 

[Kurt_Nelson]

I would say a refractometer is a must have and not just a nice to have item for SW aquarium, IMHO.

Agree 100%.

One other thing to do next time you're at a LFS or ordering online is to get some salinity meter (conductivity) calibration fluid. The stuff I have from Pinpoint is 53 mS, which equates to about a salinity of 35, or a SG of about 1.0265. You should also check your refractometer against this solution to insure you're reading correctly at the salinities we're dealing with, and not just at zero.

I just wonder how much easier life will be with a digital PH gauge, instead of guessing a color match, trying to find the right light,and a good white background.
Thanks.

Personally, I think a digital pH meter would make life worse. Assuming you're in the 8.0 to 8.4 range, consistency is all you really want. And as long as you do your pH test in the same light all the time (same room, same lights), you should be able to recognize subtle differences from test to test. Whether or not its 8.2 or 8.4 or 8.15234 really doesn't matter... it should just be the same color all the time. My personal feeling is that measuring pH out to the hundredths (when the accuracy of the things isn't that great to start with) is just an exercise in futility. But then, I've never owned one (surprise, huh?!) and can't speak from experience. Maybe if I had one, I'd think it was the best thing since sliced bread.

But I doubt it.

 

[joeyfromlawrenceville]

Kurt,
You made me laugh

I am recognizing the difficulty of keeping 4 tanks going. 3 display and one QT/Hospital.. I am a bit overwhelmed with the constant attention a hyposalinity QT needs to keep going. I am going to have to buffer PH in it due to the lack of salt , I wish I had a digital readout with PO4, Ammonia, PH, SG and Nitrate on every tank ! Sure would save me a lot of time, stupid me hasn't even bought the quick dip test strips ( like I use w/ my pool) , might make life easier for weekly tests.
As far as the other solution ( SG 1.026), found it on dr fosters site earlier today, will order once I get a list together. I am hopeing that the 1.000 calibration will be good for the hyposalitity testing at 1.009. Sure beats using the float needle, I think I would have killed my fish w/o the refractometer.

Thanks for the tip on PH, I was obsessed for a while to get it to stay at 8.3, weekly PWC w/o adding buffer mine stay 8.0/8.1 pretty constantly. What your saying is constant PH is best, as long as it is over 8.0.

PS: Now at day 4 and salt is down to 1.014 , tomorrow might be the day to drip down to 1.010 over an hour or so. Then Tuesday fine tune to 1.009 and hold for what will feel like an eternity Amonia has been a problem, doing 25 % PWC daily to keep it in a somewhat safe range.:?

Thanks for your help.

 

[Kurt_Nelson]

Ahhhh... forgot you were doing hypo. You're right - a pH meter would be nice for that. And yeah, with hypo a refractometer is an absolute must.