With regard to Po4 how low is too low?

[Randy Holmes-Farley]

Thanks Randy so u r suggesting I need to further lower my po4? I thought as far as u r between 0 to 0.03 u should be good right?]

I said it wasn't too low not that it was too high. It is fine.

 

[tripdad]

I'm loathed to stop the NoPox because where I have it at the moment at 1.8ml keeps the No3 in check at 5 and I don't want to cure one problem only to cause another.

Sometimes you can be phosphate limited, in other words you need some PO4 to help lower the No3, they work in tandem. In an ideal situation they will find a balance, say a very mature reef. It's hard to trust mother nature sometimes but it's been working for millions of years. Not saying get crazy with either one, just try adding a little PO4 and see what happens.

 

[Reef Able]

I said it wasn't too low not that it was too high. It is fine.

haha thanks for clearifying...

 

[sghera64]

As I said I mistakingly thought you were using the Phosphate Hanna not the Phosphorus checker. BRS tested the two against the Hok(sp?) and known strengths of Po4. At 0 the Phosphate was giving 0 and was still giving zero right up to when it gave 0.04 at 0.08 concentration. Its stated accuracy is +-0.04ppm plus minus 4% of the reading so in other words as it shows in their test it was still reading 0 even at a test level of 0.04. The resolution is 0.01 so I'm wrong in that it would probably possibly read 0 up to 0.06 as opposed to 0.07 if you take into account the +-0.04 and the further 4% of the reading error that can be present.
The Phosphorous checker which has an accuracy of +-5ppb and 5% of the reading, this equates to 0.015ppm and 5% ie much more accurate than the Phosphate checker at 0.04. The Phosphorous checker has a resolution of 1ppb which equates to 0.003ppm as opposed to the Phosphate checkers 0.01ppm.
Thes may be very low errors but such low readings they can be significant.
As your using the Phosphorus check so it doesn't matter, your getting more accurate readings anyway

My bad. I did not read your words correctly (or slow down enough to grasp your meaning). Your second post did it for me. All is well.

 

[Joe Batt]

Sometimes you can be phosphate limited, in other words you need some PO4 to help lower the No3

Thanks for the input and I agree with your point. However, I don't want my No3 any lower than 5 as my tank suffers at anything lower. I would like the Po4 to be more stable, as my No3 is. I think its a factor of being away so often and the corals not getting properly fed when I am.

 

[tripdad]

That's my point. If you stop the NoPox, the nitrate should rise then when you add the PO4 the natural process will bring down both to acceptable levels , leaving some PO4 around.

 

[rkpetersen]

When my phosphorus fell to 0.0 (as measured by Hanna Phosphorus colorimeter and confirmed by Triton ICP-OES), some of my corals definitely suffered. Some LPS would close up and some would start to expel algae excessively (although none actually bleached). I haven't had any SPS problems that I could definitely link to 0 phosphate though. Removing GFO and feeding fish a bit more brought things to right within a few days.

 

[madcanary]

I struggled for ever with 0 ppb and 0 nitrates. I finally got a reading when I switched from strictly pellets to frozen. I feed a pinch of either pe mysis flake, pe mysis pellet or spectrum pellet. Frozen pe mysis pm the nori every 2 days. I have 8 fish in a 180 system. My SPS are starting to look amazing. I also run full triton system. I’m running around 8-10 ppb consistently now.

 

[Hans-Werner]

Which phosphate concentration is too low depends from the growth history of the individual coral. Especially in Acropora corals grown under elevated phosphate concentrations seem not to tolerate low phosphate concentrations the other corals grown under these same low phosphate concentrations tolerate.

Low phosphate concentrations slow down growth, again especially in Acropora spp.. In my eyes low phosphate concentrations is everything below 0.03 ppm phosphate. "Easiest" phosphate concentrations are around 0.05 ppm phosphate in my opinion. Up to 0.1 ppm phosphate is fine. I would prefer to elevate the phosphate concentration via feeding of fish. Inorganic phosphate solutions may create swings in phosphate concentrations leading to adsorption of phosphate to rocks and substrate and in this way causing cyanobacterial growth medium-term.

 

[Stigigemla]

I agree about the Phosphate levels. A few years ago - before the led lights it was a hunt of low phospate level but today with stronger leds it is still very good colors with 0,1 in phosphate.

About algae and cyano there is a few things to think about. Any surface will be colonized of the species that fits the best there. A zero phosphate or nitrate level in the water column does not say that you have no phosphate or nitrate circulating in your system. It only says that corals, algae or cyano is able to consume all of it.

If you have zero or very, very low phosphate it will often come cyano. The usual algae grow very slow or not but cyano has the ability of sinking the pH under their mat and so phosphate can be released from sand or rock. Sometimes it lowers the pH so much that hydrogen sulfide is coming and the sand or stone under the cyano is getting black.

 

[Hanna Instruments]

Thank you for using our products! If anyone has any questions please feel free to reach out anytime!

Phosphorus to phosphate conversion table
http://hannainst.com/resources/aquarium/guides/phosphorus-to-phosphate-conversion-table--hanna-instruments.pdf

Phosphates in your Reef Tank
http://hannainst.com/resources/aqua...ates-in-your-reef-tank--hanna-instruments.pdf

8 Checker Best Practices Blog
http://blog.hannainst.com/checker-best-practices

 

[Joe Batt]

Thank you for using our products! If anyone has any questions please feel free to reach out anytime!

Phosphorus to phosphate conversion table
http://hannainst.com/resources/aqua...phate-conversion-table--hanna-instruments.pdf
Phosphates in your Reef Tank
http://hannainst.com/resources/aqua...ates-in-your-reef-tank--hanna-instruments.pdf

8 Checker Best Practices Blog
http://blog.hannainst.com/checker-best-practices

All excellent testers....except the Ca which I tend to have problems with and have resorted back to Salifert tests for the Ca

 

[Hanna Instruments]

All excellent testers....except the Ca which I tend to have problems with and have resorted back to Salifert tests for the Ca

The Calcium Checker requires freshwater lacking calcium for proper analysis. The use of distilled water (purified with steam distillation) from your local pharmacy or ultra-pure deionized water is required. It’s important to note that water from many hobby-grade reverse osmosis deionization resins may not be suitable for this test. Depending on the filter effectiveness, frequency of resin replacement, or water storage method used, calcium may still be present in home RODI water which could result in false high results when used during C1 stage in the Calcium Checker.

Also never wash Checker cuvettes with tap water; this is especially important for the HI758 Calcium Checker. The HI758 uses a 100 to 1 dilution to analyze calcium, and since the sample size is only 100uL (0.1ml), residual amounts of calcium from tap water can affect your results.

Also make sure you are using the upgraded kit which includes the HI731339P Graduated Pipette (100 µL)

 

[silvernblackr35]

I had the same issues about a year ago, I always had problems keeping most lps and especially acans. I ran a very dense ball of chaeto in a 29gal refugium and a gfo reactor and registered 0phos and 0 nitrate. Sps growth was slow and colors weren't so great, it wasn't until I removed the chaeto and gfo reactor that I saw my tank really come to life. Now I just run gfo passively in a media bag with carbon. I have also switched to more of a display type of refugium with different graciliara and other slower growing algaes compared to chaeto or calurpa, so I still get the nutrient removal just not as aggressive. Nitrates hover around 10ppm and I stopped measuring phosphate altogether. I think there's no argument that chaeto definitely works, sometimes too well like in my case.

 

[sghera64]

The Calcium Checker requires freshwater lacking calcium for proper analysis. The use of distilled water (purified with steam distillation) from your local pharmacy or ultra-pure deionized water is required. It’s important to note that water from many hobby-grade reverse osmosis deionization resins may not be suitable for this test. Depending on the filter effectiveness, frequency of resin replacement, or water storage method used, calcium may still be present in home RODI water which could result in false high results when used during C1 stage in the Calcium Checker.

Also never wash Checker cuvettes with tap water; this is especially important for the HI758 Calcium Checker. The HI758 uses a 100 to 1 dilution to analyze calcium, and since the sample size is only 100uL (0.1ml), residual amounts of calcium from tap water can affect your results.

Also make sure you are using the upgraded kit which includes the HI731339P Graduated Pipette (100 µL)

I wash/soak my cuvettes with HCL and DI water every once in a while.

 

[Randy Holmes-Farley]

The Calcium Checker requires freshwater lacking calcium for proper analysis. The use of distilled water (purified with steam distillation) from your local pharmacy or ultra-pure deionized water is required. It’s important to note that water from many hobby-grade reverse osmosis deionization resins may not be suitable for this test. Depending on the filter effectiveness, frequency of resin replacement, or water storage method used, calcium may still be present in home RODI water which could result in false high results when used during C1 stage in the Calcium Checker.

Also never wash Checker cuvettes with tap water; this is especially important for the HI758 Calcium Checker. The HI758 uses a 100 to 1 dilution to analyze calcium, and since the sample size is only 100uL (0.1ml), residual amounts of calcium from tap water can affect your results.

Also make sure you are using the upgraded kit which includes the HI731339P Graduated Pipette (100 µL)

I would suggest that a second generation product that wasn't as hypersensitive to calcium in the blank would be a good step forward. As it stands now, this method seems to have a 100-fold multiplier on calcium in the blank, and hence the reason for special water.

A second improvement would involve larger sample sizes, making the syringe accuracy not quite as critical.

If the method used 5 mL of sample, and not 0.1 mL, both problems would seem to be greatly reduced.

 

[sghera64]

I had the same issues about a year ago, I always had problems keeping most lps and especially acans. I ran a very dense ball of chaeto in a 29gal refugium and a gfo reactor and registered 0phos and 0 nitrate. Sps growth was slow and colors weren't so great, it wasn't until I removed the chaeto and gfo reactor that I saw my tank really come to life. Now I just run gfo passively in a media bag with carbon. I have also switched to more of a display type of refugium with different graciliara and other slower growing algaes compared to chaeto or calurpa, so I still get the nutrient removal just not as aggressive. Nitrates hover around 10ppm and I stopped measuring phosphate altogether. I think there's no argument that chaeto definitely works, sometimes too well like in my case.

Question for everyone. For those of you (us) using macro algae to remove NO3 and PO4 from the water column, doesn't the possibility exist that the algae is removing those to basic constituents and then returning "some" of the nitrogen and phosphorous back to into the water in the form of more complex organic molecules containing nitrogen and phosphorous which:

1.) our tests cannot read and,

2.) our corals CAN/DO use as N- and P- sources of food (either directly or indirectly via enzymatic and symbiotic microbial processes)?

 

[Hanna Instruments]

I would suggest that a second generation product that wasn't as hypersensitive to calcium in the blank would be a good step forward. As it stands now, this method seems to have a 100-fold multiplier on calcium in the blank, and hence the reason for special water.

A second improvement would involve larger sample sizes, making the syringe accuracy not quite as critical.

If the method used 5 mL of sample, and not 0.1 mL, both problems would seem to be greatly reduced.

Great suggestions, I will pass this along to R&D. In its current state the HI758 Calcium Checker uses an adaptation of the Zincon method. The Checkers all utilize a 10ml cuvettte and same path length/form factor. For the most part, the inclusion of the new pipette has dramatically reduced end user complaints with this Checker. We regularly validate method accuracy and test procedures in house. The main issues found were inconsistent sample delivery (which was fixed by including a new graduated pipette) and type of water used during C1 (blank) phase. Nevertheless we appreciate your suggestions and feel free to DM us is you ever have any other ideas to help improve our products!

 

[Randy Holmes-Farley]

Question for everyone. For those of you (us) using macro algae to remove NO3 and PO4 from the water column, doesn't the possibility exist that the algae is removing those to basic constituents and then returning "some" of the nitrogen and phosphorous back to into the water in the form of more complex organic molecules containing nitrogen and phosphorous which:

1.) our tests cannot read and,

2.) our corals CAN/DO use as N- and P- sources of food (either directly or indirectly via enzymatic and symbiotic microbial processes)?

FWIW, the same can be true of other organisms (bacteria, corals etc.) and not just macroalgae. They can all release soem organic matter.

You can test for organic phosphate if you want. An ICP (e.g., triton test) counts both inorganic P and organic sources of P. Hach also makes a kit, but it is tedious to use.

Corals and other organisms can potentially make use of some types of organic N and P, and not others. There's no easy way distinguish the usable ones from the not-usable ones.

 

[tgionet]

I would suggest that a second generation product that wasn't as hypersensitive to calcium in the blank would be a good step forward. As it stands now, this method seems to have a 100-fold multiplier on calcium in the blank, and hence the reason for special water.

A second improvement would involve larger sample sizes, making the syringe accuracy not quite as critical.

If the method used 5 mL of sample, and not 0.1 mL, both problems would seem to be greatly reduced.

I've been saying this since I bought my Ca checker.