Beth.....

[frogger]

being it is that you are the hypo guru, I have a couple of q's for you. First, what is a good brand namd for a refractometer. Or better yet, what is one to stay away from?
Also, if I were to take my swing arm and compare the reading to a refractometer, couldn't I use it(the swing arm) after adjusting (if needed) for hypo??? Would save a lot of bucks.
Tanks
Anyone else' input would also be much appreciated.

 

[seaguru]

Read the post on page 2 of this section titled Refractometer a must?
<a href="https://www.saltwaterfish.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=10&t=002016" target="_blank">www.saltwaterfish.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=10&t=002016</a>
Regards, Joe.

 

[beth]

Thanks for the compliment, but I'm not really a "guru".
I'm in the process of assessing myself weather to get a refractormeter or salinity monitor, and it looks like its going to be a salinity monitor. I've been using a glass hydrometer.
The problem with the precision in hyposalinity is that you must get the specific gravity down low enough for hypo to be effective, thus the need for accuracy. However, a lot of hobbyists use hydrometers for hypo and end up tinkering around with adjusting it. When a crisis is at hand, however, this "tinkering" and lack of precision can be nerve racking.
The refractormeter tends to be cheaper than the salinity monitor with a starting price for a good one running around $70+. A salinity monitor will run around $115+. The salinity monitor is more convenient, but that doesn't mean that the refract is inconvenient.
If you want to save money and not get the refract, then be sure to get a top quality glass hydrometer [not the swing arms]. The swing arms readings can vary from one test reading to the other, so doing what you suggest, still won't necessarily give you an accurate reading.

 

[frogger]

thank you both! What exactly is a salinity monitor?

 

[beth]

Just another instrument that measures salinity level using a probe. It is battery or AC powered. You basically can place the probe in the water to obtain an immediate reading, rather than the refractometer, where you have to get drop of water from the tank, place it on the glass of the refract and then take the reading yourself.
Pinpoint probably makes the most popular salinity monitors, including many other type of water reading type monitors.

 

[jdl/dayton]

I would hope when using any probe a test is run on a standard solution from time to time. Solution can be as simple as putting a teaspoon of salt mix in a known volume of water. Take a reading the first time it is used then repeat the process exactly every so often to make sure the probe is functioning properly.
To trust a probe for very long without checking to make sure it is functioning properly is dangerous.

 

[beth]

dayton, probes are calibrated periiodically just as refracts.

 

[jdl/dayton]

Just making sure people realize how important it is to verify the numbers one is reading.
I am leary of instruments which promise such precision that are only $115. Basically when it comes to analytical instruments price definately equals quality.

 

[beth]

Yes, we could use the monitors that are used by reserachers, at $1000.+, but that is ludicrious for your average hobbyist.
What would you suggest as an alternative, dayon? Hobby refracts usually cost less than the monitor.