Salinity Refractometer

[fatfishman]

I have seen a salinity refractometer for sale form an online shop for £35 and was wondering if anyone has any experience with these types salinity testers.

Do you have one like this?

Are they any good?

Do you think this is worth it?

Heres the link http/www.coralgarden.net/product_info.ph...products_id=365 please take a look

Thankyou very much everyone

 

[n3ont3tra]

It's probably fine. It looks like the one I have... make sure to calibrate it correctly.

 

[fatfishman]

It's probably fine. It looks like the one I have... make sure to calibrate it correctly.

Ok thanks n3ont3tra, you calibrate them using distilled water dont you?

 

[dilbert]

Probably not. I got a salinity-30 standard liquid that came with my electronic conductivity meter. Sometimes I'll also have to buy a new fresh standard liquid.

 

[n3ont3tra]

Quote from SkiFletch:

Ok I'll paraphrase Randy's directions for you guys tongue2.gif

1) Procure 2L soda bottle or anything else that holds 2L of water
2) Measure into the bottle 1/4 cup of plain old iodized table salt
3) Add 1 more teaspoon of salt to the bottle
4) Add 2 liters of RO water to the bottle
5) Shake vigorously until dissolved
6) Let stand to equillibrate to room temp

The resulting solution has a salinity of 35ppt or a specific gravity of 1.026 at 25 degrees C. So, if you make that solution and your Hydrometer tells you say 1.022, it is reading .004 below the standard and should be normalized. So then you take that same hydrometer and measure your tank and get 1.024 for a reading, that in actuality is 1.028 and too high... Make sense?

 

[chrissaysyes]

You could also do what I do and get your LFS to test your swing arm against their refractometer...if they carry one that is.

 

[n3ont3tra]

And if theirs is properly calibrated.

 

[chrissaysyes]

blasphemy!

 

[SkiFletch]

fatfishman, that looks like a typical low-end refractometer, just like I use. And obviously since I posted that, it's the cal standard I use . Calibrating against 0 is not a great idea when using cheap refractometers as if their prism isn't perfect (and few cheap ones are), the cal can be off by the time you get up to 35ppt or 1.026sg

 

[alexlark]

@ fatfishman - Looks OK. I bought mine off ebay. It came from Hong Kong and was only £20! And that was including P&P!!!

@ SkiFletch - Do you keep your tank at 35ppt? (Just wondering as I've only had my tank set up for 4 weeks).

Alex

 

[fatfishman]

Thanks every one, i think ill go with this one then and make sure to calibrate it accurately, unless anyone has a better, cheap alternative.

 

[SkiFletch]

Yes Alex, I try to keep mine at 35ppt, sometimes 36ppt though