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View Full Version : Phosphate levels never change


nudifun
01/30/2014, 10:08 AM
Just set up a new reef, it is 70 gallons total volume and it includes a sump/refugium. I cycled it and it has been the perfect little tank. no water quality issues to speak of and the water cycled perfectly normally, if not a bit fast. I check my levels twice a week and I am very OCD when it comes to keeping my test kits in perfect order and clean. I know how much just a small change in the quality of your method can effect the outcome of the test. This is why I remain anal and very very clean when testing my water. I also use to different testing kits (both are up to date and are not expired).

I use Red Sea as my main testing kit and I use API just to verify that the tests are close to the same thing. All my other test kits (for both brands) work very well. Obviously the Red Sea kit is a bit more accurate and easy to read but on the whole they both do what they are supposed to. My issue lies with the Phosphate component of the Red Sea kit and the API kit. Most of my complaint is with the Red Sea kit though as that's the one I count on for accurate readings and it was expensive, lol.

Besides the fact that the oil-like substance in regent B is impossible to get out with squeezing so hard the drip-tip pops off. The real problem lies with the readings themselves. Now I do appreciate Red Sea's attention to detail. Their Phosphate kit includes utilities that make the results easier to read than the other kits. Which means they are aware of how difficult the results can be to read. I'm not sure if anyone else has a problem reading their phosphate results, but I do. Its very hard for me to figure out what the reading is. The colors are just to close to each other to tell. The fact that it looks different in different light also causes problems.

I will find myself running to the window to get natural light, then to under the ceiling light to check it out under warm Incandescent light. then on the to fuge light which is still warm but a bit cooler, at 6500k power compact. Then finally on to the tank light itself which is 4-bulb t5 ho with 50/50 actinic and 12k. This little parade [profanity] and leaves me confused and not really sure what my Phosphates are.

Sorry for the length of this question/description, I just feel its better to get all the info out there so I do not get solutions that I have already thought of, down or the likes. So as a reminder the test kits are up to date and i have tried more than one and I have checked the readings under multiple different light sources. I have even checked with others to see what reading the see when they look at it.

I consistently get a reading of .08ppm, right on. Two of the other colors look similar and under certain lighting it could maybe be one of the other two colors. This has been the case since setting up the tank. The phosphates have always read .08 ppm, no matter what. I have add two large bags of Chemi-pure Elite. I stuck them between the bubble trap partitions to make sure the get the most flow. I also have a refugium stuffed with three different kinds of macro-algae, including, Calurpa, Dragon's Breath, and Chaeto.

I added these items to try and drop the phosphate levels. I added the macros first. about a week after the tank was completely cycled. I waited a few more weeks and did not see a change in phosphate levels, they remained at .08ppm. So I added the two large bags of Chemi-Pure Elite. waited a few weeks and tested again. The macro-algae has been in there for about two months and grown a whole lot. That's when I took out about half its mass and then waited another few weeks and tested again.

This is where I am at now. the phosphates remain at a disappointing .08ppm and I do not know what to do. I have tried Purigen as well and I will be trying GFO in a reactor next, but I need to save up and make room for that. besides that I am at a loss. I could try another phosphate kit or go up to the LFS and have them test the phosphate to see what it says but it will probably come out the same old .08ppm.

Does anyone have this issue or can give me some advice that i have not already tried?

Levels:
Ammonia- 0
Nitrite- 0
Nitrate - 2
Phosphate - .08
Ca - 420
Mag - 1340
PH - 8.1
Alk - 9
Salinity - 1.023
Temp - 80

bertoni
01/30/2014, 02:13 PM
Have you tried testing some RO/DI water? It should measure zero.

How much algae is being harvested out of the tank, and how often? Algae only reduce the phosphate level in a tank when their volume increases, and that'll reach a limit in a finite growing area. After that, the interior portions will die off and release nutrients at the same rate that the outer layers grow.

brian2kgt
01/30/2014, 02:29 PM
Maybe there is something wrong with your regent B or the drip-tip? In my kit it is kinda thick but it comes out very easily.

downbeach
01/30/2014, 03:03 PM
A lot of threads on the subject here:

http://reefcentral.com/forums/showthread.php?t=2278664

dkeller_nc
01/30/2014, 03:22 PM
One of the potential issues that you have is not the Red Sea test per se, but the chemistry of phosphate testing in water in general. Most manufacturer's tests are adapted from wet chemistry tests in "Standard Methods for the Examination of Water and Wastewater" that has been in continuous (though revised) publication since 1905.

The method for the measurement of orthophosphate in water relies on a color complex of phosphate with molybdenum (typically supplied as ammonium molybdate). The color is blue, and at relatively high phosphate concentrations that would be found in, for example, wastewater, the color is intense enough to be reasonably quantifiable.

But at the levels we're interested in measuring (sub 1 ppm), the color just isn't strong enough to be visually quantifiable - it requires a photometer or spectrophotometer, and even then, distinguishing the signal from the noise can be difficult.

That's partially why the Hanna phosphate checkers are popular. In theory, they provide a cost-effective method of quantitating the blue color at very low phosphate concentrations. In practice, however, turbidity in the sample, problems with solubility of the reagents, and a myriad of other issues make using the Hanna Checker problematic.

waxhawreefer
01/30/2014, 05:38 PM
a gfo reactor will definitely lower ur levels, try the ones from bulk reef supply, they have some great videos on it, but really everyone seems to have that problem, Ive been trying the new red sea stuff-no3-po4 havent been using it long enough to say if it works!

nudifun
01/31/2014, 11:26 AM
Have you tried testing some RO/DI water? It should measure zero.

How much algae is being harvested out of the tank, and how often? Algae only reduce the phosphate level in a tank when their volume increases, and that'll reach a limit in a finite growing area. After that, the interior portions will die off and release nutrients at the same rate that the outer layers grow.

I harvested about half the other day, it didn't change anything though. I just got my own RODI today!!! finally.....so I will be installing it tonight and it came with a built in TDS meter so We will see soon. I had been getting my RODI from my LFS. That could be the culprit for sure. Ijust find it odd that by changing the water chemistry, drastically sometimes the phosphate levels to not wander at all.

nudifun
01/31/2014, 11:34 AM
One of the potential issues that you have is not the Red Sea test per se, but the chemistry of phosphate testing in water in general. Most manufacturer's tests are adapted from wet chemistry tests in "Standard Methods for the Examination of Water and Wastewater" that has been in continuous (though revised) publication since 1905.

The method for the measurement of orthophosphate in water relies on a color complex of phosphate with molybdenum (typically supplied as ammonium molybdate). The color is blue, and at relatively high phosphate concentrations that would be found in, for example, wastewater, the color is intense enough to be reasonably quantifiable.

But at the levels we're interested in measuring (sub 1 ppm), the color just isn't strong enough to be visually quantifiable - it requires a photometer or spectrophotometer, and even then, distinguishing the signal from the noise can be difficult.

That's partially why the Hanna phosphate checkers are popular. In theory, they provide a cost-effective method of quantitating the blue color at very low phosphate concentrations. In practice, however, turbidity in the sample, problems with solubility of the reagents, and a myriad of other issues make using the Hanna Checker problematic.


Hanna phosphate checker, huh? I will have to check that out thank yoU! I agree about the tests on the market today, though. Its ridiculous=, 99% of the testing aquarists will be doing will be right around or under the ppm mark. yet nothing is done to improve the method for doing so. This goes for PH as well. Which i am also having trouble with from time to time.

When I was only using API kits I could never get the High Ph test to actually show a color on the damn card! it would come out as a maroonish red which is not even remotely close to being on the card. I don't know what maroon indicates.
So when I moved to the Red Sea kits, I was finally able to get a discernible reading. At first it was reading fine, during cycling. IT would raise and lower and I could make out the color normally, However these days I am getting the color reading that correlates the closest with 7.8. Every time. I add a buffer, test the next day and the PH is still 7.8 even though the alk as increased.

Any ideas or advice for PH?

downbeach
01/31/2014, 12:20 PM
Hanna for PO4. For pH, if you're looking for some semblance of accuracy, you should have some kind of metering device, i.e. Pinpoint, RK, Apex. etc. with a properly calibrated lab grade probe.

dkeller_nc
01/31/2014, 03:15 PM
Don't add buffer. In the seawater carbonate buffering system, dissolved carbon dioxide is the biggest influence on pH. There have been plenty of reports on RC about newer houses (i.e., better sealed) developing an enriched CO2 atmosphere, which in turn influences pH in the tank. Many have reported pH increases by piping the air supply for the skimmer from outdoors (or possibly another room in the house).

bertoni
01/31/2014, 04:55 PM
pH at 7.8 is fine, and that's a fairly normal level for a house with the windows shut. I agree that carbon dioxide is the issue there.

brad_G
01/31/2014, 05:24 PM
The problem is the red sea test kit. Mine would always read .08. Got me wondering so I tested fresh mixed io. .08 tested the water coming out of my gfo..... .08. Then I tested my ro...... .08. Finally I tested bottled distilled water yup .08.