How long for Nitrate and phosphate to change?

Scubajoe1 · 04/14/2018, 06:09 PM

So I have a 180 gallon with 22 fish. My phosphates and nitrates read 0 on the hanna ultra low phosphorus test and red sea kit respectively. I bumped up from 2 frozen cubes a day and 12"x6" of seaweed to the same seaweed but 4 cubes a day. 2 days now and still not shift in phosphates or nitrates. I am guessing the excess food if any will take 5 to 7 days to break down? How much do people usually feed 22 average fish on average? I know there are a ton of variables like the quality of filtration etc...

Thanks

Joe

bertoni · 04/14/2018, 10:59 PM

That's going to be hard to estimate. I might give it another week before increasing the feeding, but I suspect that you would have seen an effect by now, unless the extra food is going into growing more small animals or maybe some sort of alga.

mcgyvr · 04/15/2018, 07:56 AM

IMO it can take weeks to see a measurable effect from increasing feeding if at all..

Too many variables to how much to feed too..
big difference between 22 x 1" fish vs 22 x 10" fish,etc...

I'd have to ask why you are increasing feeding anyways? I'm going to assume that you noticed thinning of your fish? If not is there another reason other than just spending more money on food? Maybe you have corals and are having problems with them?

hkgar · 04/15/2018, 03:02 PM

What are the fish you have?

I have a 180 with 14 fish and the 3 tangs alone will eat 1 large Romaine lettuce leaf and 1/2 sheet (4" x 8") of Nori. I feed two 3 grams frozen (home made) at 6PM and the auto feeder drops a pinch of pellets 3 times a day. My nitrates and phosphate (2 and .03) would rise significantly is I wasn't dosing carbon and using a algae scrubber.

Dan_P · 04/15/2018, 06:06 PM

Fish excrete ammonia. You can assume they don’t hold onto it for long. Ammonia is used to make biomass and serves as an energy source. Bacteria and phytoplankton are going to assimilate it quickly. The biochemistry is fast.

You will see nitrates when you exceed the systems capacity, which can increase of course, to assimilate ammonia and destroy nitrate. Since the denitrification process is a slow growth system, I guess it would be only a matter of be days for the system to start having a nitrate rise under an increasing feeding regime. Unfortunately, it might be weeks before reaching the detection level of our test kits.

Increase your feeding by a cube every 3-7 days and monitor your nitrates just before each increase, or some such scheme.

Scubajoe1 · 04/15/2018, 06:58 PM

Quote:

Originally Posted by hkgar

What are the fish you have?

I have a 180 with 14 fish and the 3 tangs alone will eat 1 large Romaine lettuce leaf and 1/2 sheet (4" x 8") of Nori. I feed two 3 grams frozen (home made) at 6PM and the auto feeder drops a pinch of pellets 3 times a day. My nitrates and phosphate (2 and .03) would rise significantly is I wasn't dosing carbon and using a algae scrubber.

21 fish total. 1-6" hippo. Two fairly large foxfaces, 3 anthias, scopus tang, sailfin tang, spotted mandarin, long nose hawk, 3 clowns, rainford goby, filefish, swallowtail angel, midas blenny. two solar wrasses, leopard wrasse, koi wrasse.

I also dose carbon source only 8 mL of Nopox a day

Scubajoe1 · 04/15/2018, 07:00 PM

Quote:

Originally Posted by mcgyvr

IMO it can take weeks to see a measurable effect from increasing feeding if at all..

Too many variables to how much to feed too..
big difference between 22 x 1" fish vs 22 x 10" fish,etc...

I'd have to ask why you are increasing feeding anyways? I'm going to assume that you noticed thinning of your fish? If not is there another reason other than just spending more money on food? Maybe you have corals and are having problems with them?

Increasing feeding because more fish crap means more nutrients for my SPS coral. Also want to get my nitrates and phosphates on a measurable sale. Right now they are 0.

Dan_P · 04/18/2018, 05:47 PM

I have a 40 gallon fish only tank. I recently tried feeding the fish whole clams and wasn’t very careful about amounts. NO3 went from undetectable to 0.6 ppm within 6 days. So, things can change quickly.

Uncle99 · 04/18/2018, 07:54 PM

Maybe half the NoPox dose to 4 or 5mls and measure each week?
That should elevate them...

bertoni · 04/18/2018, 09:40 PM

I'd back off on the NOPOX. It's consuming nitrate and phosphate from the water column, if it's working at all.

04/14/2018, 06:09 PM	#1
Scubajoe1 Registered Member Join Date: Jan 2015 Location: Raleigh, NC Posts: 409	How long for Nitrate and phosphate to change? So I have a 180 gallon with 22 fish. My phosphates and nitrates read 0 on the hanna ultra low phosphorus test and red sea kit respectively. I bumped up from 2 frozen cubes a day and 12"x6" of seaweed to the same seaweed but 4 cubes a day. 2 days now and still not shift in phosphates or nitrates. I am guessing the excess food if any will take 5 to 7 days to break down? How much do people usually feed 22 average fish on average? I know there are a ton of variables like the quality of filtration etc... Thanks Joe __________________ Scubajoe 180 Gallon reef tank with coast to coast Herbie overflow. 60 Gallon sump with 9" filter sock. 36" lifereef skimmer, activated carbon filter. Emperor Aquatics 40W UV Sterilizer Current Tank Info: 180 gallon reed tank, coast to coast overflow, herbie overflow. Life reef sump and 36" life reef skimmer, GHL Doser 2, Neptune Apex reef controller, Auto topoff, Spectrapure RO system with a Tunze RO controller. activated carbon and no more GFO.

04/14/2018, 10:59 PM	#2
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	That's going to be hard to estimate. I might give it another week before increasing the feeding, but I suspect that you would have seen an effect by now, unless the extra food is going into growing more small animals or maybe some sort of alga. __________________ Jonathan Bertoni

04/15/2018, 07:56 AM	#3
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	IMO it can take weeks to see a measurable effect from increasing feeding if at all.. Too many variables to how much to feed too.. big difference between 22 x 1" fish vs 22 x 10" fish,etc... I'd have to ask why you are increasing feeding anyways? I'm going to assume that you noticed thinning of your fish? If not is there another reason other than just spending more money on food? Maybe you have corals and are having problems with them? __________________ Who me?

04/15/2018, 03:02 PM	#4
hkgar Registered Member Join Date: Oct 2002 Location: Dewitt MI Posts: 5,051	What are the fish you have? I have a 180 with 14 fish and the 3 tangs alone will eat 1 large Romaine lettuce leaf and 1/2 sheet (4" x 8") of Nori. I feed two 3 grams frozen (home made) at 6PM and the auto feeder drops a pinch of pellets 3 times a day. My nitrates and phosphate (2 and .03) would rise significantly is I wasn't dosing carbon and using a algae scrubber. __________________ Gary 180 gallon, 40 gallon sump, 3 250 W MH + 4 80W ATI T5's, MTC MVX 36 Skimmer, Apex controller Aquamaxx T-3 CaRx Current Tank Info: A 2 Barred Rabbitfish, Red Head Salon, Yellow/Purple, McMaster Fairy, Possum, 2 Leopard Wrasses, Kole, & Atlantic Blue Tangs, 2 Percula Clown, 3 PJ and 1 Banggai Cardinalfish , Swallowtail, Bellus and Coral Beauty Angels

04/18/2018, 09:40 PM	#10
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	I'd back off on the NOPOX. It's consuming nitrate and phosphate from the water column, if it's working at all. __________________ Jonathan Bertoni

04/15/2018, 06:06 PM	#5
Dan_P Registered Member Join Date: Aug 2014 Posts: 1,432	Fish excrete ammonia. You can assume they don’t hold onto it for long. Ammonia is used to make biomass and serves as an energy source. Bacteria and phytoplankton are going to assimilate it quickly. The biochemistry is fast. You will see nitrates when you exceed the systems capacity, which can increase of course, to assimilate ammonia and destroy nitrate. Since the denitrification process is a slow growth system, I guess it would be only a matter of be days for the system to start having a nitrate rise under an increasing feeding regime. Unfortunately, it might be weeks before reaching the detection level of our test kits. Increase your feeding by a cube every 3-7 days and monitor your nitrates just before each increase, or some such scheme.

04/18/2018, 05:47 PM	#8
Dan_P Registered Member Join Date: Aug 2014 Posts: 1,432	I have a 40 gallon fish only tank. I recently tried feeding the fish whole clams and wasn’t very careful about amounts. NO3 went from undetectable to 0.6 ppm within 6 days. So, things can change quickly.

04/18/2018, 07:54 PM	#9
Uncle99 Crab Free Zone Join Date: Sep 2017 Location: Ontario, Canada Posts: 2,906	Maybe half the NoPox dose to 4 or 5mls and measure each week? That should elevate them...