How should i lower my SG? just got refractometer.

Radioheadx14 · 10/19/2007, 03:24 PM

I just got my refractometer (should got it a while ago) and i want to make sure its calibrated right. I used a coralife hydrometer which seemed accurate... or at least consistent. they hydrometer says my SG is 1.022 and my refractometer says its 1.026. Eek. i want to calibrate it to make sure its correct so i can slowly lower my SG.

Well after i calibrated it with bottled water, it is still 1.026 which seems a little higher than i want.

If i have a 75g and a 20g sump, how should i lower my SG to 1.024? should i do it over the course of a week, 2 weeks etc?

I have 2 ocellaris clowns, 3 skunk cleaner shrimp and several snails and hermits.

Andrew · 10/19/2007, 03:46 PM

Calibrate it with fresh water. There should be a small screw at the top or bottom and that's how you adjust most refractometers. Freshwater of course will read at 0 but if it doesn't just adjust it. What brand is it?

sjm817 · 10/19/2007, 04:34 PM

Do not calibrate your refractometer with FW. You need to calibrate it with a 35 PPT solution.

GSMguy · 10/19/2007, 04:59 PM

your salinity is fine if anything only lower it to 1.025

Radioheadx14 · 10/19/2007, 05:11 PM

well which is it? i read on the manual that you should use distilled water.

xtm · 10/19/2007, 05:21 PM

I calibrate my 'fracto with RO/DI water. put a drop on the slide and set the screw to zero. Been doing this for so many years without any issues.

sjm817 · 10/19/2007, 05:24 PM

If you want the refracto accurate (you do), FW is a poor choice for calibration. Mine was off by .003 when calibrated with RO/DI.
Refractometers and Salinity Measurement

carlos_fb · 10/19/2007, 05:54 PM

Get the PINPOINT SALINITY CALIBRATION FLUID

http://www.thefilterguys.biz/refractometers.htm

DrBDC · 10/19/2007, 06:05 PM

Ditto the above regarding the pinpoint salinity solution. My refractometer is off by .004. So when I think I'm at 1.026 I'm only at 1.022. NSW is 1.026 so that is the best place to keep it anyway. FWIW I really like the conductivity meter by pinpoint. It gets really exact at 53.0 and holds calibration for months.

Tennsquire · 10/20/2007, 11:51 AM

There's also a thread in the Chemistry forum about making your own salinity reference solution with a 2-liter bottle and table salt. I used that successfully before I found the commercially-prepared pinpoint solution with which to calibrate my refractometer. I prefer that my refractomers is accurate at 1.026, and not at 0, because I'm shooting for 1.026.

mg426 · 10/20/2007, 01:02 PM

Agreed get the Pinpoint salinity standard. WWW.premiumaquatics.com

10/19/2007, 03:24 PM	#1
Radioheadx14 Registered Member Join Date: Aug 2007 Location: Columbus, OH Posts: 1,601	How should i lower my SG? just got refractometer. I just got my refractometer (should got it a while ago) and i want to make sure its calibrated right. I used a coralife hydrometer which seemed accurate... or at least consistent. they hydrometer says my SG is 1.022 and my refractometer says its 1.026. Eek. i want to calibrate it to make sure its correct so i can slowly lower my SG. Well after i calibrated it with bottled water, it is still 1.026 which seems a little higher than i want. If i have a 75g and a 20g sump, how should i lower my SG to 1.024? should i do it over the course of a week, 2 weeks etc? I have 2 ocellaris clowns, 3 skunk cleaner shrimp and several snails and hermits. Last edited by Radioheadx14; 10/19/2007 at 04:07 PM.

10/19/2007, 04:34 PM	#3
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	Do not calibrate your refractometer with FW. You need to calibrate it with a 35 PPT solution. __________________ - Scott

10/19/2007, 04:59 PM	#4
GSMguy Registered Member Join Date: Oct 2006 Location: Northern New Mexico Posts: 17,420	your salinity is fine if anything only lower it to 1.025 __________________ Nick. Conehead. Shallow Reef club. Current Tank Info: 48"x27"x14" Envision Acrylic rimless, 6x39w ATi Sunpower, Custom ATB Deluxe Skimmer, 4x tunze nano stream,ATB flowstar 1500, ACJR, Tunze osmolator.

10/19/2007, 05:21 PM	#6
xtm Registered Member Join Date: Jan 2005 Location: Panorama City, CA Posts: 4,703	I calibrate my 'fracto with RO/DI water. put a drop on the slide and set the screw to zero. Been doing this for so many years without any issues. __________________ Function before fashion Current Tank Info: 120g SPS Tank (48x24x24)

10/19/2007, 05:24 PM	#7
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	If you want the refracto accurate (you do), FW is a poor choice for calibration. Mine was off by .003 when calibrated with RO/DI. Refractometers and Salinity Measurement __________________ - Scott

10/19/2007, 03:46 PM	#2
Andrew Registered Member Join Date: Nov 2004 Location: Columbus, OH Posts: 13,640	Calibrate it with fresh water. There should be a small screw at the top or bottom and that's how you adjust most refractometers. Freshwater of course will read at 0 but if it doesn't just adjust it. What brand is it?

10/19/2007, 05:11 PM	#5
Radioheadx14 Registered Member Join Date: Aug 2007 Location: Columbus, OH Posts: 1,601	well which is it? i read on the manual that you should use distilled water.

10/19/2007, 05:54 PM	#8
carlos_fb Registered Member Join Date: Jul 2006 Location: Michigan Posts: 879	Get the PINPOINT SALINITY CALIBRATION FLUID http://www.thefilterguys.biz/refractometers.htm

10/19/2007, 06:05 PM	#9
DrBDC Registered Member Join Date: Aug 2004 Location: Ballwin, Missouri Posts: 10,358	Ditto the above regarding the pinpoint salinity solution. My refractometer is off by .004. So when I think I'm at 1.026 I'm only at 1.022. NSW is 1.026 so that is the best place to keep it anyway. FWIW I really like the conductivity meter by pinpoint. It gets really exact at 53.0 and holds calibration for months. __________________ Some drink at the fountain of knowledge, some just gargle, but most are rabid. Current Tank Info: 180g sps+75 softy/lps on one system tunze's, seio's, mjmods, aquacontroller w/add ons, 2X400 XM10000 and 3X160 vho actinic, 110g sump, 110 frag tank, Geo Beckett and other stuff

10/20/2007, 11:51 AM	#10
Tennsquire Registered Member Join Date: Feb 2002 Location: Nashville, TN Posts: 1,399	There's also a thread in the Chemistry forum about making your own salinity reference solution with a 2-liter bottle and table salt. I used that successfully before I found the commercially-prepared pinpoint solution with which to calibrate my refractometer. I prefer that my refractomers is accurate at 1.026, and not at 0, because I'm shooting for 1.026. __________________ Nothin' left to do but smile, smile, smile.... Current Tank Info: 75 reef (2x 250 ReefOptix IIIs, AB 10k bulbs w/ 330 watt VHO, EuroReef RC135 skimmer, multicontrolled Tunze 6095's X2); 40 sps prop tank (Outer Orbit Pro 150, Euroreef CS6-1+ skimmer); 20 softie prop tank

10/20/2007, 01:02 PM	#11
mg426 Registered Member Join Date: Jan 2006 Location: maryland Posts: 6,923	Agreed get the Pinpoint salinity standard. WWW.premiumaquatics.com __________________ I found a way to make a small fortune running a reef tank. Start with a large fortune. Unofficial President of the SEACLONE haters club Current Tank Info: 125 mixed reef 110 lbs LR, 1x250watt XM 20K MH 2x175watt XM 20K MH on Magetics 2X96 watt actinic PC, 220 watt VHO actinic, 30 gallon refugium, closed loop system powered by Sequence Dart MSX 200 skimmer 38 gallon sump, Oceansmotions squirt