Phosphate consumption - 0.12ppm in 10 minutes!?

[Japtastic]

My tank is around 8 months old and does have high Nitrates at around 80ppm.

I have some Chaeto and have been carbon dosing for the last 4 weeks.

My Chaeto did start dying off around 2 months ago and I realised that I had 0 phosphates and probably the reason it started dying so I started dosing 0.04ppm per day. This would almost nearly get consumed within 24 hours. I added more fish since then and this seemed to help keep Phosphates at 0.01-0.02 so I stopped dosing.

I checked Phosphates yesterday in case they had dropped and were limiting Chaeto and Carbon dosing results. Low and behold they were 0 again.

I dosed 0.12 yesterday and confirmed it by the Red Sea Phosphate pro test. 0 again this evening. I dosed another 0.12ppm just now, confirmed it by test kit and then tested 10 minutes later and got 0 again. Confirmed this with a Hanna checker and got 0.01ppm.

What is going on here? Is my system/Chaeto/Nitrate eating bacteria so deprived that they are consuming 0.12ppm in 10 minutes and/or is something else absorbing it that quick?

Appreciate your thoughts!

 

[rkpetersen]

With nitrates that high, chaeto and carbon-fed bacteria are going to grab every molecule of phosphate as fast as they can. Unless you're accidentally running GFO or some other phosphate remover, and presuming you repeated the questionable tests at least once to rule out user error, it's likely true incorporation into biomass. You could try increasing phosphate dose amount and/or frequency until the increase registers and sticks.

 

[Cory]

So to confirm your adding .12 ppm po4 to the tank and you read .12 ppm p04 with your test kit, then later its 0?

Another possible exsplanation is its getting bound by rocks and sand.

 

[rkpetersen]

So to confirm your adding .12 ppm po4 to the tank and you read .12 ppm p04 with your test kit, then later its 0?

Another possible exsplanation is its getting bound by rocks and sand.

This occurred to me also, but the system has been running for 8 months so most of the rocks and sand should be encrusted with bacterial films and other life at this point.

 

[hart24601]

I would also suspect it's getting bound by the rock and sand.

 

[Cory]

I agree biomass can take it up fast, especially with algae and carbon dosing.

 

[Japtastic]

So to confirm your adding .12 ppm po4 to the tank and you read .12 ppm p04 with your test kit, then later its 0?

Another possible exsplanation is its getting bound by rocks and sand.

Yes, 0.12ppm to 0 in 10 minutes. 350 gallons with 1 inch sand bed and about 100kgs of rock.

So should I just keep dosing until I get to point where the tank is not consuming it within a reasonable time frame?

 

[Cory]

Yes, 0.12ppm to 0 in 10 minutes. 350 gallons with 1 inch sand bed and about 100kgs of rock.

So should I just keep dosing until I get to point where the tank is not consuming it within a reasonable time frame?

Id try dosing the same value twice per day. If you have an auto doser id dose it lots of times per day just in smaller quantities.

 

[hart24601]

You are adding phosphate which is the biggest thing imo. Don't get too caught up in chasing those low numbers, go slow. The rock and sand will bind and drop the number to 0 but when it reaches your target phosphate will go up fast! I would just stay as is for a while and look for changes and keep testing.

 

[Japtastic]

Oh yes nice and slow wins the race, hence no corals until everything is where I want it. Chasing low numbers doesn’t overly concern me, just wanted to make sure what I was expirencing wasn’t out of the ordinary. Will keep dosing and testing.

Off topic: @hart24601 I sold my GTR 18 months ago and still miss it

 

[hart24601]

Oh yes nice and slow wins the race, hence no corals until everything is where I want it. Chasing low numbers doesn’t overly concern me, just wanted to make sure what I was expirencing wasn’t out of the ordinary. Will keep dosing and testing.

Off topic: @hart24601 I sold my GTR 18 months ago and still miss it

I sold mine a few months ago too... there really is nothing like them!

 

[Chris Villalobos]

Oh yes nice and slow wins the race, hence no corals until everything is where I want it. Chasing low numbers doesn’t overly concern me, just wanted to make sure what I was expirencing wasn’t out of the ordinary. Will keep dosing and testing.

Off topic: @hart24601 I sold my GTR 18 months ago and still miss it

You ever stabilize your phosphate consumption. I'm currently having the same type of event in my 33gallon. I was slowly adding 20 lbs of Reef Flakes into my tank over a two month period. I'm almost finished adding and then all the sudden my tank is now consuming over 0.15ppm PO4 each day. Yesterday I had to add 0.2ppm just to see if today I'll test higher than 0ppm. I would have thought the aragonite would have consumed the PO4 more steadily throughout the slow additions. Now I'm thinking this is some sort of bacteria colonization event.