High Phosphates +200 on Hanna

Geebs19 · Apr 18, 2022

Hey All,

A little stumped here. Not new to reefing but this tank has been running for about 3 months now. No issues with the cycle, added fish from my old tank and bought a new one that wiped out the tank while I was out of town. Ive been running high nitrates around mid 30s, Phosphates havent been an issue until the last couple weeks. My Hanna test is at 200+ ppb, I tested RODI and it was at 5ppb. I am not sure where this all came from but I want to be able to reduce it and trying to steer clear of addatives, I do have NOPOX if needed. 2 weeks ago when I first tested the 200+ I had just got doen really blowing a bunch of crap off my rocks and I am wondering if I stirred all these phostphates out of the rocks, they were dry rock to begin with.

Current params on fallow tank

Temp: 81.1
Salinity 1.026
Ammonia 0
Nitrate 7.4 via hanna
Phostphates 200+
Calc 390
Mag 1260
Alk 6.7

TIA!

blaxsun · Apr 18, 2022

200ppb (billion) is only 0.2ppm (million), so your phosphates are only slightly elevated. Your nitrates are basically fine.

Montiman · Apr 18, 2022

Geebs19 said:
Hey All,

A little stumped here. Not new to reefing but this tank has been running for about 3 months now. No issues with the cycle, added fish from my old tank and bought a new one that wiped out the tank while I was out of town. Ive been running high nitrates around mid 30s, Phosphates havent been an issue until the last couple weeks. My Hanna test is at 200+ ppb, I tested RODI and it was at 5ppb. I am not sure where this all came from but I want to be able to reduce it and trying to steer clear of addatives, I do have NOPOX if needed. 2 weeks ago when I first tested the 200+ I had just got doen really blowing a bunch of crap off my rocks and I am wondering if I stirred all these phostphates out of the rocks, they were dry rock to begin with.

Current params on fallow tank

Temp: 81.1
Salinity 1.026
Ammonia 0
Nitrate 7.4 via hanna
Phostphates 200+
Calc 390
Mag 1260
Alk 6.7

TIA!

This actually not super high. 200 PPB is only .2ppm I would not stress about it. It sounds like you are using the ultra low range checker which is made for ultra low nutrient tanks. This is a great tool but most people would use the low range checker that reports in PPM.

Traditionally .03 PPM is ideal but IMO anything less and .5 is fine. No need to worry about .2 PPM

fryman · Apr 18, 2022

blaxsun said:
200ppb (billion) is only 0.2ppm (million), so your phosphates are only slightly elevated. Your nitrates are basically fine.

This is not correct. I think there is confusion in this thread about units. I'm only aware of one hanna which reports ppb, the HI736.

If you are using the HI736 ultra low range phosphorus checker, you need to convert ppb phosphorus to ppm phophate. There is a difference between phosphorus and phosphate. Phosphate is the parameter people typically report in the hobby and the numbers recommended above are in ppm phosphate.

There's a table to convert readings from the HI736:

https://www.hannainst.com/hubfs/006-finished-content/Aquarium/phosphorus-to-phosphate-conversion-table--hanna-instruments.pdf

Or you can multiply the reading by 3.066 then divide by 1,000

200 ppb phosphorus is over 0.6 ppm phosphate

Geebs19 · Apr 18, 2022

fryman said:
This is not correct. I think there is confusion in this thread about units. I'm only aware of one hanna which reports ppb, the HI736.

If you are using the HI736 ultra low range phosphorus checker, you need to convert ppb phosphorus to ppm phophate. There is a difference between phosphorus and phosphate. Phosphate is the parameter people typically report in the hobby and the numbers recommended above are in ppm phosphate.

There's a table to convert readings from the HI736:

https://www.hannainst.com/hubfs/006-finished-content/Aquarium/phosphorus-to-phosphate-conversion-table--hanna-instruments.pdf

Or you can multiply the reading by 3.066 then divide by 1,000

200 ppb phosphorus is over 0.6 ppm phosphate

Ya that’s the table I have been using. So I’m over .6 and I’ve done 40 Gallon water change in between the last 2 measurement and it’s still at 200. Not sure why it’s so high.

Randy Holmes-Farley · Apr 18, 2022

Geebs19 said:
Ya that’s the table I have been using. So I’m over .6 and I’ve done 40 Gallon water change in between the last 2 measurement and it’s still at 200. Not sure why it’s so high.

The primary sources of phosphate are food (by far the most common) and rock that has a lot of bound phosphate.

NOPOX and other carbon dosing methods will not be especially effective at reducing phosphate.

GFO, macroalgae, lanthanum are generally best, IMO.

Justdrew · Apr 18, 2022

fryman said:
This is not correct. I think there is confusion in this thread about units. I'm only aware of one hanna which reports ppb, the HI736.

If you are using the HI736 ultra low range phosphorus checker, you need to convert ppb phosphorus to ppm phophate. There is a difference between phosphorus and phosphate. Phosphate is the parameter people typically report in the hobby and the numbers recommended above are in ppm phosphate.

There's a table to convert readings from the HI736:

https://www.hannainst.com/hubfs/006-finished-content/Aquarium/phosphorus-to-phosphate-conversion-table--hanna-instruments.pdf

Or you can multiply the reading by 3.066 then divide by 1,000

200 ppb phosphorus is over 0.6 ppm phosphate

+1 --- .6 or higher.

areefer01 · Apr 18, 2022

So let us all just ignore the phosphate number for a minute.

How does your display look?

Geebs19 · Apr 18, 2022

areefer01 said:
So let us all just ignore the phosphate number for a minute.

How does your display look?

Excellent. No nuisance Algea out of control, just normal new tank here and there. Corals are doing good, mostly euphyllia.

EeyoreIsMySpiritAnimal · Apr 18, 2022

Geebs19 said:
Excellent. No nuisance Algea out of control, just normal new tank here and there. Corals are doing good, mostly euphyllia.

Don't fix what ain't broken

Scott Max · Jul 1, 2024

My experience with the Hanna HI736 checker is that I had to shake the vial pretty good to completely dissolve the reagent powder. In the instructions, it doesn't say to "shake vigorously", it says to "completely dissolve". Otherwise the suspended reagent particles will give a false high value, like really high, i.e 0.4 - 0.6ppm. Those erroneous results sent me in panic mode upon first using the checker. After following the instructions EXACTLY (stupid me) my repeated values were 0.07. Hope this helps new users of the Hanna kit.