Hydrometer Or Refractometer?

[kj23502]

I've read that hydrometer's are harder to use on lower sg...is that true? I was thinking of buying a refractometer to use on my future tank and was looking at one like this:


Salinity Refractometer 0-10% ATC Aquarium Salt Water
One scale checks the NaCl levels with the range of 0-100 ppt (with 1 ppt scale divisions) and the other scale gauges Specific Gravity with a range of 1.000 to 1.070 (+/- 0.001 accuracy). Both enable the direct determination of salinity in water that contains dissolved salt and little or no other dissolved solids. It is suitable for a marine saltwater tank.


The little or no other dissolved solids is what I'm hung up on....I'm assuming in a brackish tank there will be more dissolved solids

And I'll start planning for my saltwater tank as soon as my brackish is done (hoping it'll be done this fall), so a refractometer could come in handy for my future saltwater tank too.

So my main question is...would a refractometer like this work? and what about the dissolved solids part? would it mess it up?

 

[emmsy]

a refractometer is always the tool of choice for me. Just like now, I have changed my 5x2x2 from marine to tropical, and used the refractometer to check if any salt was left in the tank

Emma

 

[andywg]

For brackish a hydrometer is fine. The brackish environment is naturally changing in salinity, so the fish can tolerate changes. furthermore, many people who own refractometers are kidding themselves with the accuracy, the ones we can afford have quite a drift from 0 to 35 ppt salinity, so unless you calibrate with a known salinity solution that is close to 35ppt (as opposed to 0ppt with salt water) then you will not be as accurate as you would think.

I believe there was a good thread on hydro v refracto on RC and the hydros are actually more accurate at our price point. However more important than what you have is knowing how to use, read and maintain it.

 

[kj23502]

Thanks for the replies!!

It may be useless, but I'm now reading on getting a 35 ppt solution to calibrate a refractometer...and even then...the solution is only as good as their way of measuring...i guess.

Andywg: Is RC reef central? I'll read up on that as well!!! (If it is, there's a guy on there breeding black and white clowns and documenting it as well as trying to raise them...that's part of what pushed me to get the black and white clowns (eventually...when my tank is ready) instead of nemo's. I'm not going to try to breed them or raise their fry, though. I just think they look more interesting.)

 

[kj23502]

Jsut thought I'd share that I found a site that sells 35 ppt solution for calibration purposes, just in case anyone was curious...like me. (in the U.S.)


http/www.vernier.com/accessories/access....late=basic.html

 

[dilbert]

Fish and other animals are used to changing salinities.

The main reason for staying with a particular one is the nitrifying bacteria. They might have problems to adapt to rapidly changing salinities.

The only reason to measure salinity at all is not to end up off the limits with the time.

 

[kj23502]

Fish and other animals are used to changing salinities.

The main reason for staying with a particular one is the nitrifying bacteria. They might have problems to adapt to rapidly changing salinities.

The only reason to measure salinity at all is not to end up off the limits with the time.

What do you mean off the limits with the time? I was thinking of starting a brackish journal here in a couple months when I get most of it gathered and start setting up.... Whacha all think? Would you like see that?

It's nothing rare....29 gallon south american puffer and goby tank. I plan to plant it also. A put a tid bit of driftwood in.

 

[dilbert]

I mean if you have a SG of 1.005, e.g., and you do always water changes with SG 1.010 (assuming it'll be 1.005), then at some time, you'll end up with SG 1.010.

The bacteria might adapt very well if you do regular water changes but maybe you got plants or animals that should rather stay with SG 1.005 than with 1.010.

 

[kj23502]

Ok thanks!! I'll be keeping it between 1.003 and 1.005. Around that general area is what nmonks suggested. I'll be able to have a few more freshwater plants at the lower sg.

 

[kj23502]

Since I will be putting together a saltwater in a year or 2, would it be better to buy a refractometer that I can calibrate, then? I eventually want to have corals in my SW so I'd need to be accurate. I really don't want to buy 2 separate things.

 

[nmonks]

To be honest I'd buy a $5 floating glass hydrometer for the brackish water aquarium. Learn about how to use this basic tool properly. Learn the relationship between salinity, temperature, and specific gravity (e.g., with Brack Calc). Once you understand why salinity and specific gravity are different things, you'll be in a prime position to take on reef keeping where your scope for experimentation is much less.

So don't get hung up on the accuracy of the instrument; rather, concentrate on improving the usefulness of the results you obtain.

Cheers, Neale

 

[kj23502]

To be honest I'd buy a $5 floating glass hydrometer for the brackish water aquarium. Learn about how to use this basic tool properly. Learn the relationship between salinity, temperature, and specific gravity (e.g., with Brack Calc). Once you understand why salinity and specific gravity are different things, you'll be in a prime position to take on reef keeping where your scope for experimentation is much less.

So don't get hung up on the accuracy of the instrument; rather, concentrate on improving the usefulness of the results you obtain.

Cheers, Neale

Will do the hydrometer!! Thanks everyone!