API Phosphate

nanojg · 01/12/2018, 10:13 AM

I wonder if this should be trusted at all? I know its definitely not reliable to test low levels of phosphates, but I wonder what a level of .25 means with this kit (does it mean somewhere between 0 and .5?). The two lowest levels on this kit are .25 and zero.

I set my tank up about a month ago, after my cycle I had about 40 ppm of nitrate. Since then I do daily water changes of 1 gallon (30 gallon tank, so maybe call it 20 gallon water volume give or take).

My nitrates have been zero since a week after the cycle.

All I have in the tank is one YWG, couple rics and a clean up crew.

I have hermit crabs and they have killed at least three snails, I need to get them out, but even with the snails the nitrate still reads zero every time I test it (since the initial reading of 40 post cycle).

I had a small diatom bloom at the time my cycle was complete, but that went away in less than a week. Since then no visible algae (about 1.5 weeks).

I tested freshly mixed salt water and the phosphates read .25. Its possible I have phosphates in my RO water (no DI), but I evaporate about 2.5 gallons a week and if I really am adding .25 phosphates with the top off water I would think my phosphate level would be much higher than .25 by now.

I could easily see the source of phosphate to be the dry rock I used, but the freshly mixed salt water also shows the .25.

I am running GFO, so I guess it could be taking out the excess, but it just doesn't seem right.

I guess I should just get a hanna ultra low checker. Any other thoughts.

reefgeezer · 01/12/2018, 10:42 AM

If your phosphates are truly .25 ppm, the GFO will be exhausted quickly. Get a Hanna ULR Checker and go from there.

nereefpat · 01/12/2018, 10:47 AM

Quote:

Originally Posted by nanojg

Since then no visible algae (about 1.5 weeks).

Then I wouldn't worry about it.

Just my opinion.

nanojg · 01/12/2018, 11:05 AM

nereefpat, that's what I was thinking...the API test kit is incorrect and my phosphates are very low.

ReeferNoob4ever · 01/13/2018, 10:58 PM

I use API for phosphates and it's garbage. I have to guess unless it's .25ppm anything less and I'm making assumptions. I will be getting a Hanna checker and suggest you do the same. If nothing else, for your sanity's sake!

outssider · 01/14/2018, 05:14 PM

If you get the hanna, get the phosphorus checker 736 not the phosphate checker 713. the 736 is much more accurate at very low levels.

bertoni · 01/14/2018, 05:35 PM

The API kit might be off, but it's not going to tell you much about the phosphate level towards the low end where we run our tanks. The Hanna Phosphorus ULR Checker gets generally good reviews. The Hach and Salifert kits have worked for me, as well.

ReeferNoob4ever · 01/14/2018, 10:59 PM

I would prefer to keep my phosphates at about .1ppm so I don't think I need the ultra low, so keep that in mind OP, you do have two options with the hanna checker.

homer1475 · 01/15/2018, 05:12 AM

Unless you want to keep ULN system, just get the regular phosphate test.

Just watched a BRS video on the difference between the 2 and for me the regular phosphate kit will be just fine. Again unless you want to keep ULN there wasn't much difference between the 2 until you get the extreme low end of the kits measurements(ULN), which most of us are not trying to accomplish.

At .04PPM phosphate there was only a 2% difference between the 2. Most of us just want to keep phosphate low, not nonexistent.

Timfish · 01/15/2018, 06:24 AM

I've compared the API to Elos and Nyos at it seemed pretty close but at the low end Elos and Nyos (and hanna) are going to be easier. I've compared Hanna to Elos and it's faster but I found Elos easier to use. FYI .25 PO4 is with in the range of normal for reefs. Be careful of dropping PO4 too low as it can cause phosphate deficiency and really mess up the coral/zooxanthellae simbiosis. Here's the links to the research, note it was done on corals grown for at least 2 1/2 years in a ULNS system with carbon dosing

https://pdfs.semanticscholar.org/d70...07f906d0d4.pdf
https://www.sciencedirect.com/scienc...77343513001917

bertoni · 01/15/2018, 05:13 PM

At the low end, the Phosphorus ULR Checker is accurate to about ±.015 ppm. The Phosphate Checker is about ±0.04 ppm.

TwentyfiveCents · 01/15/2018, 09:55 PM

Get a hanna UL checker

nanojg · 01/21/2018, 11:15 AM

.09 on the ulr checker

Hair algea is starting to grow.

Wonder if i should increase gfo?

Its a new tank so algae stages should be expected, but should i focus on lowering the phosphates?

0 nitrates everytime i test, but obviously the algea is sucking up some

bertoni · 01/21/2018, 06:24 PM

The tank is only about a month old, so I wouldn't worry much. The phosphate level might decrease with a bit more growth, but a bit more GFO might help. With the level that high, the media might be exhausted in a few hours. When the phosphate result out of the reactor matches the tank, the media is shot.

nanojg · 01/26/2018, 08:07 AM

I have been doing daily 2 gallon water changes for the last five days. Tested today first test was 1nu (inverted samples or something???), second test was a blinking 0 (instructions say this could indicate an error).

Maybe my phosphates are near zero. My algea is dying out (my filter floss turns dark brown in a day).

Have you seen the 1nu or blinking 0 test result?

Also, I finally added a DI about a week ago. I'm sure I had phosphates in my RO water.

bertoni · 01/26/2018, 05:51 PM

I haven't used the ULR Checker, but according to the manual, the issue is with the zero reference cuvette being more blue than the sample. I might clean the cuvettes carefully, but I suspect the results are getting close to the detection limit.

01/12/2018, 10:13 AM	#1
nanojg Registered Member Join Date: Jan 2009 Location: Lubbock, Texas Posts: 2,174	API Phosphate I wonder if this should be trusted at all? I know its definitely not reliable to test low levels of phosphates, but I wonder what a level of .25 means with this kit (does it mean somewhere between 0 and .5?). The two lowest levels on this kit are .25 and zero. I set my tank up about a month ago, after my cycle I had about 40 ppm of nitrate. Since then I do daily water changes of 1 gallon (30 gallon tank, so maybe call it 20 gallon water volume give or take). My nitrates have been zero since a week after the cycle. All I have in the tank is one YWG, couple rics and a clean up crew. I have hermit crabs and they have killed at least three snails, I need to get them out, but even with the snails the nitrate still reads zero every time I test it (since the initial reading of 40 post cycle). I had a small diatom bloom at the time my cycle was complete, but that went away in less than a week. Since then no visible algae (about 1.5 weeks). I tested freshly mixed salt water and the phosphates read .25. Its possible I have phosphates in my RO water (no DI), but I evaporate about 2.5 gallons a week and if I really am adding .25 phosphates with the top off water I would think my phosphate level would be much higher than .25 by now. I could easily see the source of phosphate to be the dry rock I used, but the freshly mixed salt water also shows the .25. I am running GFO, so I guess it could be taking out the excess, but it just doesn't seem right. I guess I should just get a hanna ultra low checker. Any other thoughts.

01/12/2018, 10:42 AM	#2
reefgeezer Registered Member Join Date: Dec 2009 Location: Wichita KS Posts: 2,621	If your phosphates are truly .25 ppm, the GFO will be exhausted quickly. Get a Hanna ULR Checker and go from there. __________________ John, Current Tank Info: In-process, 90 Gallon SPS Reef

01/13/2018, 10:58 PM	#5
ReeferNoob4ever Registered Member Join Date: Mar 2017 Location: NM Posts: 523	I use API for phosphates and it's garbage. I have to guess unless it's .25ppm anything less and I'm making assumptions. I will be getting a Hanna checker and suggest you do the same. If nothing else, for your sanity's sake! __________________ Get a life! Current Tank Info: 20gL mixed reef, 10g mixed reef w/nem & clown, 5g NPS & harlequin

01/14/2018, 05:35 PM	#7
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	The API kit might be off, but it's not going to tell you much about the phosphate level towards the low end where we run our tanks. The Hanna Phosphorus ULR Checker gets generally good reviews. The Hach and Salifert kits have worked for me, as well. __________________ Jonathan Bertoni

01/14/2018, 10:59 PM	#8
ReeferNoob4ever Registered Member Join Date: Mar 2017 Location: NM Posts: 523	I would prefer to keep my phosphates at about .1ppm so I don't think I need the ultra low, so keep that in mind OP, you do have two options with the hanna checker. __________________ Get a life! Current Tank Info: 20gL mixed reef, 10g mixed reef w/nem & clown, 5g NPS & harlequin

01/12/2018, 11:05 AM	#4
nanojg Registered Member Join Date: Jan 2009 Location: Lubbock, Texas Posts: 2,174	nereefpat, that's what I was thinking...the API test kit is incorrect and my phosphates are very low.

01/14/2018, 05:14 PM	#6
outssider Registered Member Join Date: Nov 2009 Location: Reseda, Ca. Posts: 1,717	If you get the hanna, get the phosphorus checker 736 not the phosphate checker 713. the 736 is much more accurate at very low levels.

01/15/2018, 05:12 AM	#9
homer1475 Registered Member Join Date: Mar 2015 Location: Upstate NY Posts: 5,313	Unless you want to keep ULN system, just get the regular phosphate test. Just watched a BRS video on the difference between the 2 and for me the regular phosphate kit will be just fine. Again unless you want to keep ULN there wasn't much difference between the 2 until you get the extreme low end of the kits measurements(ULN), which most of us are not trying to accomplish. At .04PPM phosphate there was only a 2% difference between the 2. Most of us just want to keep phosphate low, not nonexistent. __________________ 80G SCA Build: http://reefcentral.com/forums/showthread.php?t=2560256 Originally posted by der_wille_zur_macht: "He's just taking his lunch to work"

01/15/2018, 06:24 AM	#10
Timfish Registered Member Join Date: Jul 2010 Location: Austin, TX Posts: 1,985	I've compared the API to Elos and Nyos at it seemed pretty close but at the low end Elos and Nyos (and hanna) are going to be easier. I've compared Hanna to Elos and it's faster but I found Elos easier to use. FYI .25 PO4 is with in the range of normal for reefs. Be careful of dropping PO4 too low as it can cause phosphate deficiency and really mess up the coral/zooxanthellae simbiosis. Here's the links to the research, note it was done on corals grown for at least 2 1/2 years in a ULNS system with carbon dosing https://pdfs.semanticscholar.org/d70...07f906d0d4.pdf https://www.sciencedirect.com/scienc...77343513001917 __________________ "Our crystal clear aquaria come nowhere close to the nutrient loads that swirl around natural reefs" Charles Delbeek

01/15/2018, 05:13 PM	#11
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	At the low end, the Phosphorus ULR Checker is accurate to about ±.015 ppm. The Phosphate Checker is about ±0.04 ppm. __________________ Jonathan Bertoni

01/15/2018, 09:55 PM	#12
TwentyfiveCents Registered Member Join Date: May 2017 Location: mobile Posts: 33	Get a hanna UL checker

01/21/2018, 11:15 AM	#13
nanojg Registered Member Join Date: Jan 2009 Location: Lubbock, Texas Posts: 2,174	.09 on the ulr checker Hair algea is starting to grow. Wonder if i should increase gfo? Its a new tank so algae stages should be expected, but should i focus on lowering the phosphates? 0 nitrates everytime i test, but obviously the algea is sucking up some

01/21/2018, 06:24 PM	#14
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	The tank is only about a month old, so I wouldn't worry much. The phosphate level might decrease with a bit more growth, but a bit more GFO might help. With the level that high, the media might be exhausted in a few hours. When the phosphate result out of the reactor matches the tank, the media is shot. __________________ Jonathan Bertoni

01/26/2018, 08:07 AM	#15
nanojg Registered Member Join Date: Jan 2009 Location: Lubbock, Texas Posts: 2,174	I have been doing daily 2 gallon water changes for the last five days. Tested today first test was 1nu (inverted samples or something???), second test was a blinking 0 (instructions say this could indicate an error). Maybe my phosphates are near zero. My algea is dying out (my filter floss turns dark brown in a day). Have you seen the 1nu or blinking 0 test result? Also, I finally added a DI about a week ago. I'm sure I had phosphates in my RO water.

01/26/2018, 05:51 PM	#16
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	I haven't used the ULR Checker, but according to the manual, the issue is with the zero reference cuvette being more blue than the sample. I might clean the cuvettes carefully, but I suspect the results are getting close to the detection limit. __________________ Jonathan Bertoni