I keep dosing phosphates but they keep disappearing!

[Miami Reef]

20 gallon QT with A large maxima clam and about 15 small acro frags. 2 pieces of small/medium rocks, no sand.

I have 80 astrea snails inside (they are getting QT) I’m dosing 10mL of neophos from brightwell about every day but it shoots back down to 0.01-0.02ppm every day as well.

In addition to dosing phosphates, I am feeding the snails these algae wafers.

My phosphates have this large rise and drop daily while nitrates are being kept stable around 5-6ppm

What am I doing wrong here? It seems like phosphates drop 0.07ppm daily.

I do 10% water changes weekly and dose Sodium Carbonate and Calcium Chloride every hour during the daytime cycle.

I don’t have much algae growth but I am dealing with mild Dino’s which has decreased by a lot (maybe 5-10% remaining).

I want to grow algae in the tank instead of dinos and I want my corals to have N and P.

 

[dvgyfresh]

Are the rocks new ?

 

[Miami Reef]

Are the rocks new ?

Nope. But they were in the tank while it was in its low nutrient stage. I’ve been dosing phosphates pretty heavily for a week already.

The only thing I’m thinking is that my organisms are consuming my phosphates too rapidly, but how does that explain that nitrates never drop to 0?

 

[dvgyfresh]

Nope. But they were in the tank while it was in its low nutrient stage. I’ve been dosing phosphates pretty heavily for a week already.

The only thing I’m thinking is that my organisms are consuming my phosphates too rapidly, but how does that explain that nitrates never drop to 0?

That’s the biggest thing I can think of besides the clam , the rocks may not yet be saturated fully and sucking up all phosphate

 

[rmorris_14]

Nope. But they were in the tank while it was in its low nutrient stage. I’ve been dosing phosphates pretty heavily for a week already.

The only thing I’m thinking is that my organisms are consuming my phosphates too rapidly, but how does that explain that nitrates never drop to 0?

Stick with me here.....Don't you have to have phosphates in order to reduce nitrates? So if your phosphates are bottoming out, it might not reduce your nitrates any further? Ive heard of people having to increase their phosphates in order to reduce their nitrates. Sounds like a questions for someone more qualified though... At least this will bump your post. ;)

 

[Reefbuds]

This happened to me for a while when I was getting my phosphates off 0. Idk where it all went but I was burning thru a ton of phosphates as well. Proboly the corals and bacteria using it up until it reaches a critical mass. It should level out eventually and you won't have to dose it anymore. Keep dosing. Keep testing until your regular feeding provides enough phosphates for the tank on its own. Just my opinion tho dude, lots of factors could be contributing tho so it's very biased off your particular tank situation

 

[Reefbuds]

Reef roids are a fantastic source of phosphates as well

 

[thatmanMIKEson]

Try

 

[Reefbuds]

Try

I've always read that benereef does not increase nutes. Mostly the reason I use it.. altho I'm not sure about the 0 nutes part. What's your experience?

 

[thatmanMIKEson]

I've always read that benereef does not increase nutes. Mostly the reason I use it.. altho I'm not sure about the 0 nutes part. What's your experience?

I believe it helps to raise both n03 and p04, unlike reef roids that seems to only raise p04. I have absolutely no evidence to support that, but I like both and use both, I lean a little more to the benepets side though.

 

[MaxTremors]

It’s likely your rock absorbing it. I had to dose around 3 bottles of neophos before my rocks reached saturation. Dosed daily for a couple months, but they reached saturation one day and then any further dosing caused a huge spike. Just test frequently, you’ll reach saturation point eventually.

 

[Dan_P]

20 gallon QT with A large maxima clam and about 15 small acro frags. 2 pieces of small/medium rocks, no sand.

I have 80 astrea snails inside (they are getting QT) I’m dosing 10mL of neophos from brightwell about every day but it shoots back down to 0.01-0.02ppm every day as well.

In addition to dosing phosphates, I am feeding the snails these algae wafers.

My phosphates have this large rise and drop daily while nitrates are being kept stable around 5-6ppm

What am I doing wrong here? It seems like phosphates drop 0.07ppm daily.

I do 10% water changes weekly and dose Sodium Carbonate and Calcium Chloride every hour during the daytime cycle.

I don’t have much algae growth but I am dealing with mild Dino’s which has decreased by a lot (maybe 5-10% remaining).

I want to grow algae in the tank instead of dinos and I want my corals to have N and P.

Could you have enough algae growth to consume the PO4? Could you increase the PO4 dose?

 

[Sean Clark]

I'll vote for the rock soaking it up. Keep at it and you will get the PO4 to stableize.

 

[Miami Reef]

Could you have enough algae growth to consume the PO4? Could you increase the PO4 dose?

I actually don’t have any algae. The only “algae” I have is very very mild Dinos that only seem to collect on the filter floss. The rest of the tank is cristal clean.

I actually did increase the dose this morning. I will test again now and see what levels I get. I’ll report back.

 

[Chrisv.]

My vote is that the large maxima clam is the culprit:

Aquacultured giant clams, Tridacna gigas
and Hippopus hippopus, used as the main biofilter in a saltwater aquarium recirculation system
https://www.spc.int/DigitalLibrary/Doc/FAME/InfoBull/TROC/8/TROC8_24_Braley.pdf

 

[Miami Reef]

Here’s my tank. Seems like phosphates are registering after my phosphate spike today. I did dose more heavily than ever today because I can’t have my phosphates dip to 0.01-0.02 every day. I need the minimum to be at least 0.05ppm

 

[Chrisv.]

Here’s my tank. Seems like phosphates are registering after my phosphate spike today. I did dose more heavily than ever today because I can’t have my phosphates dip to 0.01-0.02 every day. I need the minimum to be at least 0.05ppm

I would be EXTREMELY surprised if that small amount of rock was sucking up all your phosphate. I think it's the zooxanthellae in your clam.

 

[Miami Reef]

I would be EXTREMELY surprised if that small amount of rock was sucking up all your phosphate. I think it's the zooxanthellae in your clam.

That’s what I was thinking!

I actually spiked my phosphates super high (I think I probably dosed 15mL-20mL of Neophos in the morning and the result is probably around…I’ll update. My test kit needs 5 more minutes (using Red Sea pro)

 

[Miami Reef]

Alright, I had dinner. The phosphates are 0.08-0.12ppm

I was definitely expecting it to be higher.

So, my goal is to dose 15mL a day and bump is by 5mL if it isn’t meeting my demands.

The QT should be completed in 6 weeks from today. :)

 

[Randy Holmes-Farley Verified Community Expert]

I would be EXTREMELY surprised if that small amount of rock was sucking up all your phosphate. I think it's the zooxanthellae in your clam.

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.

https://www.reef2reef.com/threads/phosphate-absorption-rates-in-aragonite.352405/
"Total: 57.4 ppm in water column to .1748 ppm after aragonite was introduced."