Is your Red Sea Phosphate test kit reading 0.08?

[Crashnt24]

Yeah, I thought mine was too.

My kit has been reading 0.08 for over a year. I chalked it up to me being awesome and having a really stable tank. Boy was I wrong.

I finally pulled the trigger on a Hanna Phosphate colorimeter. It arrived last night, so naturally I used it. I like to play with my new toys immediately. Well it read 0.2!

If you are using Red Sea phosphate kits, beware of this problem. Especially since I have seen multiple threads where someone says their PO4 is 0.08 using the Red Sea kit.

 

[MnFish1]

Yeah, I thought mine was too.

My kit has been reading 0.08 for over a year. I chalked it up to me being awesome and having a really stable tank. Boy was I wrong.

I finally pulled the trigger on a Hanna Phosphate colorimeter. It arrived last night, so naturally I used it. I like to play with my new toys immediately. Well it read 0.2!

If you are using Red Sea phosphate kits, beware of this problem. Especially since I have seen multiple threads where someone says their PO4 is 0.08 using the Red Sea kit.

Curious - what is the problem? Now you have 2 tests that disagree. So - it seems to me that you need a third test to confirm which is incorrect? PS - is there any evidence that the PO4 is super high in your tank? PS - I have found the Hanna tests to be fairly unreliable (i.e. multiple tests of the same sample gave different results). Thats just my experience though. I also found the Redsea tests difficult to read. Why do you think they would consistently read '0.08'? is it difficulty reading the color, expired test kit, etc?

 

[Crashnt24]

Curious - what is the problem? Now you have 2 tests that disagree. So - it seems to me that you need a third test to confirm which is incorrect? PS - is there any evidence that the PO4 is super high in your tank? PS - I have found the Hanna tests to be fairly unreliable (i.e. multiple tests of the same sample gave different results). Thats just my experience though. I also found the Redsea tests difficult to read. Why do you think they would consistently read '0.08'? is it difficulty reading the color, expired test kit, etc?

I don't know what causes the stuck 0.08 in the red sea. All I know is that it makes sense to me that something is off in the reagents. I doubt I'll get a 3rd test either. What's important to me is to be able to see changes in water chemistry. If I use GFO or lanthium I want to see changes. If I increase feedings of pellets I want to see changes.

With the red sea I was never seeing changes, now with a working test(hanna) I can see the rate of changes when I run GFO. After I tested last night I turned on my reactor with GFO, I'm down to .16 on the hanna while my red sea still says 0.08. Lol

Oh and I have been battling GHA for a year, that's the only negative thing I'm seeing from the high PO4. Which makes sense on why I wasn't beating it. .2 is way too high.

 

[Mike konesky]

Red sea was consistently giving me zero. Bought the newer hanna (ulr ppm) and it reads .03-.04. 2 icp tests says undetectable. Back to dosing phos.

 

[MnFish1]

I don't know what causes the stuck 0.08 in the red sea. All I know is that it makes sense to me that something is off in the reagents. I doubt I'll get a 3rd test either. What's important to me is to be able to see changes in water chemistry. If I use GFO or lanthium I want to see changes. If I increase feedings of pellets I want to see changes.

With the red sea I was never seeing changes, now with a working test(hanna) I can see the rate of changes when I run GFO. After I tested last night I turned on my reactor with GFO, I'm down to .16 on the hanna while my red sea still says 0.08. Lol

Oh and I have been battling GHA for a year, that's the only negative thing I'm seeing from the high PO4. Which makes sense on why I wasn't beating it. .2 is way too high.

FWIW - I wasnt trying to criticise you - but I think its important to realize that there is no way to know which test is correct. Its pretty normal for PO4 to be constant. Truth be told - in a mature tank - you really shouldn't see much change - with feeding, etc - unless you're really 'overfeeding' - because organisms in the tank rapidly take it up. I do not believe you should be seeing a change of .21 - .16 with a GFO reactor that quickly? BTW - did you buy the 'high range' or the 'low range' checker?

 

[Uncle99]

.2ppm phosphate is not a “bad” level for a tank, moderately stocked with corals and more than a year old.
All the hobby grade tests for phosphate have margin of error, the question IMM is the level increasing, decreasing or stable.
Maybe your configuration runs well at .2ppm and is easy to keep there. Any maybe Hanna is out so it’s actually .15ppm, we don’t always know exactly, but close counts here.

I certainly distrust anytime I get the exact same answer.

I trust Hanna to at least, report more consistently on colour variations than my eyes.

 

[maxtek]

Thanks for posting this. I read this and it immediately registered that my weekly phosphate tests (Red Sea) have been at 0.08 for a while. Hanna ULR says 0.4 with back to back tests! ICP on 12/1 said 0.1, and I have a second ICP currently inflight. Not sure what to believe at the moment.

 

[CNDReef]

Now I have to double check my results with the Hanna ulr. My RS test has been 0.08 for the past 6 tests

 

[MnFish1]

Thanks for posting this. I read this and it immediately registered that my weekly phosphate tests (Red Sea) have been at 0.08 for a while. Hanna ULR says 0.4 with back to back tests! ICP on 12/1 said 0.1, and I have a second ICP currently inflight. Not sure what to believe at the moment.

Curious - to both you and the OP - what Units are you using for 'PO4'? For example - the Phosphat Pro (Redsea) - gives PPM PHOSPHATE as a result. The Hanna ULR units are ppb 'PHOSPHOROUS'. You can't compare the results equally - depending on the test you're using. If you're using the high range hanna checker - You will get PHOSPHATE results in PPM - BUT the margin of error is +- 1 ppm (+- 5 percent)

 

[MnFish1]

PS - it is not surprising to me that many people are seeing 0.08 on their Redsea kit. After all there are only 7 possible results (..04, .08, .12, etc). So a reading that 'looks' like 0.08 could actually be .05 - .1. Depending on how well one's eyes render color. I personally (with my eyes) see very little difference between 0.08 and 0.16. The reason everyone sees 0..08 would seem to be because thats a level around which most people have their tanks - and lets face it - you cant get a result of .07 or .10

 

[maxtek]

I used HI774 Phosphate ULR to obtain that 0.4 shocker

 

[DrMMI]

Yeah, I thought mine was too.

My kit has been reading 0.08 for over a year. I chalked it up to me being awesome and having a really stable tank. Boy was I wrong.

I finally pulled the trigger on a Hanna Phosphate colorimeter. It arrived last night, so naturally I used it. I like to play with my new toys immediately. Well it read 0.2!

If you are using Red Sea phosphate kits, beware of this problem. Especially since I have seen multiple threads where someone says their PO4 is 0.08 using the Red Sea kit.

I had the same problem. My kit kept reading 0.08ppm and finally I tested with a salifert and a Hanna and both were around 0.5. I realized that even though the color for 0.08 was the closest, it didn't 100% match. I guess that should have been a sign that I should have used the high range mode of the test kit.

 

[William Morris]

Keep in mind you should read the colors with a full spectrum LED light.
Makes all the difference.

 

[tundraguy1106]

Thanks for posting this. I read this and it immediately registered that my weekly phosphate tests (Red Sea) have been at 0.08 for a while. Hanna ULR says 0.4 with back to back tests! ICP on 12/1 said 0.1, and I have a second ICP currently inflight. Not sure what to believe at the moment.

Just had the same thing happen to me. .08 reading on my Hanna. ICP showed .01 and somehow I’m dealing with Dinos?!?! So for me, I dosed phosphate up to .1 on my Hanna purchased a salifert test kit (between .05-.1), and increased my peak lighting since I was having SPS die off.

 

[IslandLifeReef]

Thanks for posting this. I read this and it immediately registered that my weekly phosphate tests (Red Sea) have been at 0.08 for a while. Hanna ULR says 0.4 with back to back tests! ICP on 12/1 said 0.1, and I have a second ICP currently inflight. Not sure what to believe at the moment.

Well, the Red Sea test kit was 20% off from the ICP test. The Hanna test was 300% off of the ICP test. To me, it looks like you Red Sea kit works better for you.

I am a fan of the Hanna checker, but if you don’t follow the testing procedure exactly, it can give you wildly wrong results.

 

[Reef.]

Doesn’t the ICP tests count a different form of PO4, so the reading will be different to a home test kit?

 

[MnFish1]

Doesn’t the ICP tests count a different form of PO4, so the reading will be different to a home test kit?

ICP measures 'phosphorous'. not 'phosphate'

 

[tundraguy1106]

ICP measures 'phosphorous'. not 'phosphate'

My results show both readings.

 

[nick_md]

Huh interesting. My phosphate has been steady at about 0.08 on the Red Sea test kit as well. Despite other signs of rising nutrients in the tank. Following to see what others say.

 

[MnFish1]

Huh interesting. My phosphate has been steady at about 0.08 on the Red Sea test kit as well. Despite other signs of rising nutrients in the tank. Following to see what others say.

If you think about it a little, you can see on your tests. the ability of your Redsea kit to differentiate between .06 and .10 - i.e. none. Then consider your eyes vs everyone else so now we're .04 - .12. The redsea kits are not designed like the hanna kits (which IMHO are totally inaccurate) - to pick between those levels. In other words - in a tank that is not falling apart - most redsea tests will measure PO4 at 0.08. IMHO