Phosphates in my water change water question

benf · 06/13/2008, 08:11 PM

As some of u may know i have asked before why i am having phosphate issues...my Tank according to Hanna is .003.

Tonight i decided to test my water change water twice and according to my Hanna i got .006 and .005.

Let me explain my process and maybe u can tell me the issue. I have a 5 stage RO/DI unit and i test it before putting water in my 50gal holding tank and it test 0 tds. I have a mag pump running 24/7 in that tank circulating the water thru a marine garden hose back into the tank so i have constant water movement. When i want to do a water change i use a 37gal Rubbermaid. I add ~35gals mixed with my salt(TMPro and just bought D-D H2Ocean Magnesium Pro PLUS) and let it mix in that tub overnight.

Could the rubbermaid be a culprit? I rinse it out after every use, but dont scrub it. Could my RO/DI water holding tank be an issue since the water is in there for 2 weeks at a time? I change out the RO/DI filters regularly.

I havent but will now go ck for PO4 in the RO/DI tank.

Any ideas? Shouldnt my makeup water test at 0 for PO4? I do remember being told its normal for the holding water to test above 0 and that be normal as long as it was 0 going into the tank.

Thanks,
Ben

benf · 06/13/2008, 08:20 PM

I tested the water in the 50gal holding tank and Hanna shows .002

reef_doug · 06/13/2008, 10:51 PM

I've heard the D-D and Red Sea may have a touch of PO4 because both of them are derived from evaporated NSW. I have no direct experience with either of these though.

I'll be curious to other replies also.

Boomer · 06/13/2008, 11:14 PM

How can your Hanna be .006, or .005 or.003 ? It only goes to .02 for accuracy.

From 0.00 to 2.50 mg/L (HI 93713)

benf · 06/14/2008, 03:16 AM

Quote:

Originally posted by Boomer
How can your Hanna be .006, or .005 or.003 ? It only goes to .02 for accuracy.

From 0.00 to 2.50 mg/L (HI 93713)

Good catch....thats what i meant .06 and .05....wish it were .006

benf · 06/14/2008, 03:50 AM

I just tested the water as it leaves the RO/DI unit and i get.02 there as well. I guess i need to do a test against someone elses Hana to see if i am off by .02. IF i am correct then why am i getting .02 when the tds meter(freshly calibrated) says 0 ?

Randy Holmes-Farley · 06/14/2008, 06:35 AM

I expect that 0.02 ppm in the RO/DI is error.

Boomer · 06/14/2008, 10:32 AM

............and I agree with Randy as usually. And we have what we call "noise", where a known ppm sample may still give a reading that is off from the sample even if calibrated. Also, .02 could be .02 or .01 or less. .02 is the lower limit of the meter and anything lower is beyond the limits and capability of the meter. And it could also be a meter error as Randy pointed out, as in nose. Take note that the meter has a resolution of .01 but its accuracy is Â± 0.04 Â±4% of reading, with a typical EMC Deviation Â± 0.01 mg/L and all at 20 C / 68 F.

06/13/2008, 08:11 PM	#1
benf Premium Member Join Date: Aug 2004 Location: wesley chapel, florida Posts: 4,031	Phosphates in my water change water question As some of u may know i have asked before why i am having phosphate issues...my Tank according to Hanna is .003. Tonight i decided to test my water change water twice and according to my Hanna i got .006 and .005. Let me explain my process and maybe u can tell me the issue. I have a 5 stage RO/DI unit and i test it before putting water in my 50gal holding tank and it test 0 tds. I have a mag pump running 24/7 in that tank circulating the water thru a marine garden hose back into the tank so i have constant water movement. When i want to do a water change i use a 37gal Rubbermaid. I add ~35gals mixed with my salt(TMPro and just bought D-D H2Ocean Magnesium Pro PLUS) and let it mix in that tub overnight. Could the rubbermaid be a culprit? I rinse it out after every use, but dont scrub it. Could my RO/DI water holding tank be an issue since the water is in there for 2 weeks at a time? I change out the RO/DI filters regularly. I havent but will now go ck for PO4 in the RO/DI tank. Any ideas? Shouldnt my makeup water test at 0 for PO4? I do remember being told its normal for the holding water to test above 0 and that be normal as long as it was 0 going into the tank. Thanks, Ben __________________ Ben Current Tank Info: None :(

06/13/2008, 08:20 PM	#2
benf Premium Member Join Date: Aug 2004 Location: wesley chapel, florida Posts: 4,031	I tested the water in the 50gal holding tank and Hanna shows .002 __________________ Ben Current Tank Info: None :(

06/13/2008, 10:51 PM	#3
reef_doug Premium Member Join Date: Jul 2006 Location: Hesperia/Apple Valley Posts: 3,814	I've heard the D-D and Red Sea may have a touch of PO4 because both of them are derived from evaporated NSW. I have no direct experience with either of these though. I'll be curious to other replies also. __________________ "If you have more than one tank in your livingroom, you might be a reefneck" Current Tank Info: 180r SoCal Creations, 75g SCC1M Sump, WM EcoBAK, NextReef SMR1, TropicMarin Salt, ACIII, 3x250w HQI Phoenix 14k, 2x140w Super Actinics, ATi BM250, Eheim 1262, Tunze 2x6100+7095, Tunze Osmolator, 6 stage RODI w/ Spectrapure MaxCap

06/13/2008, 11:14 PM	#4
Boomer Bomb Technician (EOD) Join Date: Aug 2002 Location: Duluth, Minnesota Posts: 11,842	How can your Hanna be .006, or .005 or.003 ? It only goes to .02 for accuracy. From 0.00 to 2.50 mg/L (HI 93713) __________________ If you See Me Running You Better Catch-Up Seawater Chemistry, Geology, ID Marine Life, Collecting Science Books, Explosives Technology, Audiophile An explosion can be defined as a loud noise, accompanied by the sudden going away of things, from a place where they use to be.

06/14/2008, 03:50 AM	#6
benf Premium Member Join Date: Aug 2004 Location: wesley chapel, florida Posts: 4,031	I just tested the water as it leaves the RO/DI unit and i get.02 there as well. I guess i need to do a test against someone elses Hana to see if i am off by .02. IF i am correct then why am i getting .02 when the tds meter(freshly calibrated) says 0 ? __________________ Ben Current Tank Info: None :(

06/14/2008, 06:35 AM	#7
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	I expect that 0.02 ppm in the RO/DI is error. __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

06/14/2008, 10:32 AM	#8
Boomer Bomb Technician (EOD) Join Date: Aug 2002 Location: Duluth, Minnesota Posts: 11,842	............and I agree with Randy as usually. And we have what we call "noise", where a known ppm sample may still give a reading that is off from the sample even if calibrated. Also, .02 could be .02 or .01 or less. .02 is the lower limit of the meter and anything lower is beyond the limits and capability of the meter. And it could also be a meter error as Randy pointed out, as in nose. Take note that the meter has a resolution of .01 but its accuracy is Â± 0.04 Â±4% of reading, with a typical EMC Deviation Â± 0.01 mg/L and all at 20 C / 68 F. __________________ If you See Me Running You Better Catch-Up Seawater Chemistry, Geology, ID Marine Life, Collecting Science Books, Explosives Technology, Audiophile An explosion can be defined as a loud noise, accompanied by the sudden going away of things, from a place where they use to be.