I keep dosing phosphates but they keep disappearing!

[Chrisv.]

You might be surprised.

JDA did an experiment showing that 5 pounds of fresh rock in 5 gallons of water could absorb more than 50 ppm of phosphate before the levels got to 0.2 ppm.

Phosphate Absorption Rates in Aragonite

I was chatting with @mcarroll the other day about phosphate binding to aragonite. I have seen many instances where phosphate bound live rock and sand requires massive amounts of media and water changes to remove all of the phosphate. Two instances: 1). Local purchased 120lbs of Pukani live...

www.reef2reef.com

"Total: 57.4 ppm in water column to .1748 ppm after aragonite was introduced."

Wow. I AM surprised. What do you think about the clam theory?

 

[Randy Holmes-Farley Verified Community Expert]

Wow. I AM surprised. What do you think about the clam theory?

All calcifying organisms and abiotic precipitation take up phosphate into the calcium carbonate. Does the aragonite in a clam shell take up more than a similar amount in a coral? I do not have reason to think so, but I do not know for sure.

 

[Miami Reef]

All calcifying organisms and abiotic precipitation take up phosphate into the calcium carbonate. Does the aragonite in a clam shell take up more than a similar amount in a coral? I do not have reason to think so, but I do not know for sure.

I’m not seeing much new shell growth on the maxima clam though.

And I would suspect nitrates and phosphates to be taken in equal ratios.

 

[Miami Reef]

Today’s testing:

Nitrates 5.5ppm
Phosphates: 0.08ppm-0.12ppm (this was after dosing 15mL)

It seems like nitrates are just staying the same while phosphates are dropping quickly.

I am dosing 5mL of soda ash and calcium chloride daily to maintain 8dkh, and I’m getting good coralline growth, so there has to be consumption, but maybe the rocks are just absorbing a lot of the phosphates?

 

[Randy Holmes-Farley Verified Community Expert]

I’m not seeing much new shell growth on the maxima clam though.

And I would suspect nitrates and phosphates to be taken in equal ratios.

Except in the shell.