Nitrate/Phosphate Issue

WGT1014 · 07/15/2018, 01:58 PM

I have a 75 gallon tank that's been up for 5 years. Due to "life", for about 1.5 years I did nothing but feed and top off. Then maybe 4 months ago I got back into the tank again. I had a big algae/diatom issue. I bought all new test kits. I use Red Sea Pro for nitrate and phosphate. Now, here's my issue. Admittedly, I'm not that good with color charts but the phosphate has always shown to be .12 and initially nitrate was over 64. How much over? Don't know as the chart I have with the kit only goes to 64. Anyway, for the past 4 months, I've been doing 20 gallon water changes every week. I run carbon in a reactor as well as Rowaphos. Phosphate is STILL at .12 and maybe 1 month ago nitrate was at 16 but won't go any lower even tho I'm still doing the 20 gallon water change. Maybe I got a bad phosphate kit, which would explain why it never changes but what about the nitrate? I saw a definite change then it stalled.
I feed 1 cube of frozen Omega One, 1/2 in the morning and 1/2 at night plus I put in about 1/4 sheet of Nutramar Nori every couple of days.
My big question, after all that, is why hasn't the nitrate dropped below 16? Any suggestions will be appreciated...

mcgyvr · 07/15/2018, 02:52 PM

Sounds normal...
Besides water changes you havent listed any changes that would reducd them..

Got sps corals? If not your levels are just fine assuming you arent having nuisance algae issues

WGT1014 · 07/15/2018, 03:09 PM

I don't have any sps corals...I don't get how it's normal. Maybe nitrate at 16 is ok but why hasn't it been lowered because of water changes? Which was my big question. I test right before and right after I do a water change. 16 is as low as it gets. I cant believe the test kit faulty ONLY at that level. That makes no sense to me

outssider · 07/15/2018, 04:01 PM

Quote:

Originally Posted by WGT1014

I don't have any sps corals...I don't get how it's normal. Maybe nitrate at 16 is ok but why hasn't it been lowered because of water changes? Which was my big question. I test right before and right after I do a water change. 16 is as low as it gets. I cant believe the test kit faulty ONLY at that level. That makes no sense to me

research "carbon dosing".....

WGT1014 · 07/15/2018, 04:31 PM

i have but I still don't have an answer to my question...WHY did nitrates stall at 16? It's not a big deal...forget I asked

Alfrareef · 07/15/2018, 05:58 PM

Let me try explain it in a simple way.
For nitrate reduction you’ll need more bacteria. With carbon dosing you’ll give more food to the bacteria colonies thus increasing the bacteria number and they shall consume the nitrates.

I use Red Sea NOPOX for Nitrate reduction/maintenance.

Uncle99 · 07/15/2018, 06:08 PM

Quote:

Originally Posted by WGT1014

i have but I still don't have an answer to my question...WHY did nitrates stall at 16? It's not a big deal...forget I asked

Carbon dosing ( not running carbon) with either NOPox, vodka, or vinegar ( or a mix) can be done on a daily basis to slowly increase denitrifying bacteria counts and thus reduce Nitrates. 16 is not high at all, but minor consistent dosing can bring it down to say 5ppm, which is far as I go because I don't want to starve my corals.

Phosphate tests are tough to call unless you use the Hanna phosforous model. You kinda got to estimate the weakness of the colour in mist cheap kits, I use ROWA and it works great but Max's out at .05, best I can do, again you want some trace phosphates if you keep corals

nereefpat · 07/16/2018, 07:56 AM

Quote:

Originally Posted by WGT1014

WHY did nitrates stall at 16?

The twenty gallon water changes (about 27% in your case) worked well to drop you nitrates when the nitrate concentration was 60+ppm. 64 - (0.27*64) = 46.7 ppm.

As you've dropped the concentration down to 16, the 20 gallon water changes will now only drop the concentration by 4ppm.

My guess is that your tank "produces" a couple ppm a week, and your water changes knock them back a couple ppm, and you can't measure the small difference.

mcgyvr · 07/16/2018, 08:06 AM

Its likely just math...

A 20% water change will lower nitrates 20%..
When nitrates are high 20% equals more of a drop.. As nitrate levels get lower 20% isn't much anymore..

100ppm and remove 20% = reduces nitrates 20ppm
16ppm and remove 205 reduces nitrates 3.2ppm

In the time between water changes your nitrate level is increasing a few ppm as input is greater than output..

nereefpat · 07/16/2018, 08:09 AM

Great minds, mcgyvr

mcgyvr · 07/16/2018, 09:18 AM

Quote:

Originally Posted by nereefpat

Great minds, mcgyvr

Dang skippy...

I walked away from my computer mid reply hence the 10 minute difference..
Had to go find the drill for someone

nereefpat · 07/16/2018, 10:22 AM

Quote:

Originally Posted by mcgyvr

Dang skippy...

I walked away from my computer mid reply hence the 10 minute difference..
Had to go find the drill for someone

I figured. I do that all the time...office hours and whatnot.

Alfrareef · 07/16/2018, 01:20 PM

@WHT1014 your doubts went away?

WGT1014 · 07/16/2018, 06:22 PM

No my doubts did not go away...my question was STILL not answered...let me try this...Saturday at 10 am I did a nitrate test. It showed 16... IMMEDIATELY after I did a 20 gallon water change which, BTW is NOT 20% of 75 gallons....at 10:30am, same day, IMMEDIATELY after that WC I checked nitrate again and it was STILL 16...Like I said earlier, not a big deal, forget I asked...

Uncle99 · 07/16/2018, 06:37 PM

Just trying to help!

mozelsa · 07/16/2018, 06:42 PM

Sent from my iPhone using Tapatalk

WGT1014 · 07/16/2018, 06:45 PM

Uncle99, I get that you are trying to help but here's the thing...I'm not asking how to lower my nitrates, as I've said several times, I'm just trying to figure out why water changes are not affecting my nitrate levels at 16...even the "math" that got mentioned didn't help...I get the math and I'm very good at math but STILL I don't have a viable answer to my question which is ok...if no one knows, as I've said already, not a big deal, forget I asked...I'll figure it out sooner or later...

lapin · 07/16/2018, 07:19 PM

Red Sea’s Nitrate Pro Reef Test Kit is an advanced colorimetric test with comparator, measuring the level of nitrate in your reef aquarium to an exceptionally high accuracy of 0.12ppm NO3. . Im stumped, as long as the test is being done correctly. At 16 with even a 10% water change should show a reduction. My only thought would be to test the water you are using to do the water change.
Hope this is of some help.

WGT1014 · 07/16/2018, 07:31 PM

Quote:

Originally Posted by lapin

Red Sea’s Nitrate Pro Reef Test Kit is an advanced colorimetric test with comparator, measuring the level of nitrate in your reef aquarium to an exceptionally high accuracy of 0.12ppm NO3. . Im stumped, as long as the test is being done correctly. At 16 with even a 10% water change should show a reduction. My only thought would be to test the water you are using to do the water change.
Hope this is of some help.

Hmmm, ya know maybe this is helpful. I never actually thought about testing my WC water...Thank you...I will try this...

Uncle99 · 07/16/2018, 08:29 PM

Quote:

Originally Posted by WGT1014

Uncle99, I get that you are trying to help but here's the thing...I'm not asking how to lower my nitrates, as I've said several times, I'm just trying to figure out why water changes are not affecting my nitrate levels at 16...even the "math" that got mentioned didn't help...I get the math and I'm very good at math but STILL I don't have a viable answer to my question which is ok...if no one knows, as I've said already, not a big deal, forget I asked...I'll figure it out sooner or later...

I hear you, some things in this hobby can be very frustrating.
Iam sorry, I misread your post,

I don't measure to that degree of accuracy, if it 5ppm (that's ok) if it's 10 (I am somewhat concerned) when it goes to 15 (I up the carbon dose 1ml) and in one week, back to 5ppm, or maybe that's 4 or 3ppm, I find all hobby grade tests inaccurate, but on my case, only need to be on the ballpark....

WGT1014 · 07/16/2018, 09:09 PM

Quote:

Originally Posted by nereefpat

The twenty gallon water changes (about 27% in your case) worked well to drop you nitrates when the nitrate concentration was 60+ppm. 64 - (0.27*64) = 46.7 ppm.

As you've dropped the concentration down to 16, the 20 gallon water changes will now only drop the concentration by 4ppm.

My guess is that your tank "produces" a couple ppm a week, and your water changes knock them back a couple ppm, and you can't measure the small difference.

ok, then by your "math", my nitrates should go from 16 to 12 with a 20 gallon water change. then why is it that after a month of being at 16 and still doing 20 gallon water changes weekly, I'm still at 16? What my tank "produces" does not matter here because as I said a few posts back, I check nitrate before and after the water changes...it's not user error as it's always the same color...If I'm reading it wrong, so be it BUT with each water change the color should get lighter and it's not...

WGT1014 · 07/16/2018, 09:12 PM

Quote:

Originally Posted by Alfrareef

Let me try explain it in a simple way.
For nitrate reduction you’ll need more bacteria. With carbon dosing you’ll give more food to the bacteria colonies thus increasing the bacteria number and they shall consume the nitrates.

I use Red Sea NOPOX for Nitrate reduction/maintenance.

Your "simple way" was pointless...I already knew that. Thanks for NOT answering the question I asked...

WGT1014 · 07/16/2018, 09:13 PM

Quote:

Originally Posted by nereefpat

Great minds, mcgyvr

Yep and you were both wrong...grats!

WGT1014 · 07/16/2018, 09:16 PM

Quote:

Originally Posted by mozelsa

Sent from my iPhone using Tapatalk

Too bad I can't see this comment...was probably AMAZING and answered all my questions!

WGT1014 · 07/16/2018, 09:22 PM

Quote:

Originally Posted by Uncle99

I hear you, some things in this hobby can be very frustrating.
Iam sorry, I misread your post,

I don't measure to that degree of accuracy, if it 5ppm (that's ok) if it's 10 (I am somewhat concerned) when it goes to 15 (I up the carbon dose 1ml) and in one week, back to 5ppm, or maybe that's 4 or 3ppm, I find all hobby grade tests inaccurate, but on my case, only need to be on the ballpark....

It's not a big deal Uncle99...the most frustrating part, to me, is when you ask a question and people just give answers that really have nothing to do with the actual question...but, it's like that on every forum I suppose...meh...

07/15/2018, 01:58 PM	#1
WGT1014 Registered Member Join Date: Apr 2013 Location: Brewerton, NY Posts: 31	Nitrate/Phosphate Issue I have a 75 gallon tank that's been up for 5 years. Due to "life", for about 1.5 years I did nothing but feed and top off. Then maybe 4 months ago I got back into the tank again. I had a big algae/diatom issue. I bought all new test kits. I use Red Sea Pro for nitrate and phosphate. Now, here's my issue. Admittedly, I'm not that good with color charts but the phosphate has always shown to be .12 and initially nitrate was over 64. How much over? Don't know as the chart I have with the kit only goes to 64. Anyway, for the past 4 months, I've been doing 20 gallon water changes every week. I run carbon in a reactor as well as Rowaphos. Phosphate is STILL at .12 and maybe 1 month ago nitrate was at 16 but won't go any lower even tho I'm still doing the 20 gallon water change. Maybe I got a bad phosphate kit, which would explain why it never changes but what about the nitrate? I saw a definite change then it stalled. I feed 1 cube of frozen Omega One, 1/2 in the morning and 1/2 at night plus I put in about 1/4 sheet of Nutramar Nori every couple of days. My big question, after all that, is why hasn't the nitrate dropped below 16? Any suggestions will be appreciated...

07/15/2018, 02:52 PM	#2
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Sounds normal... Besides water changes you havent listed any changes that would reducd them.. Got sps corals? If not your levels are just fine assuming you arent having nuisance algae issues __________________ Who me?

07/16/2018, 08:06 AM	#9
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Its likely just math... A 20% water change will lower nitrates 20%.. When nitrates are high 20% equals more of a drop.. As nitrate levels get lower 20% isn't much anymore.. 100ppm and remove 20% = reduces nitrates 20ppm 16ppm and remove 205 reduces nitrates 3.2ppm In the time between water changes your nitrate level is increasing a few ppm as input is greater than output.. __________________ Who me? Last edited by mcgyvr; 07/16/2018 at 08:12 AM.

07/16/2018, 08:09 AM	#10
nereefpat Registered Member Join Date: Apr 2016 Location: Central Nebraska Posts: 3,190	Great minds, mcgyvr __________________ Pat Current Tank Info: 125 in-wall , 40b sump. 6 bulb T5. ASM G2 skimmer. LPS and leathers

07/16/2018, 07:19 PM	#18
lapin Registered Member Join Date: Aug 2017 Location: Austin Posts: 801	Red Sea’s Nitrate Pro Reef Test Kit is an advanced colorimetric test with comparator, measuring the level of nitrate in your reef aquarium to an exceptionally high accuracy of 0.12ppm NO3. . Im stumped, as long as the test is being done correctly. At 16 with even a 10% water change should show a reduction. My only thought would be to test the water you are using to do the water change. Hope this is of some help. __________________ Tank sizes, 2-10's a 55 and one that's about 500gal Current Tank Info: Interior decorating happening

07/15/2018, 03:09 PM	#3
WGT1014 Registered Member Join Date: Apr 2013 Location: Brewerton, NY Posts: 31	I don't have any sps corals...I don't get how it's normal. Maybe nitrate at 16 is ok but why hasn't it been lowered because of water changes? Which was my big question. I test right before and right after I do a water change. 16 is as low as it gets. I cant believe the test kit faulty ONLY at that level. That makes no sense to me

07/15/2018, 04:31 PM	#5
WGT1014 Registered Member Join Date: Apr 2013 Location: Brewerton, NY Posts: 31	i have but I still don't have an answer to my question...WHY did nitrates stall at 16? It's not a big deal...forget I asked

07/15/2018, 05:58 PM	#6
Alfrareef Registered Member Join Date: Mar 2016 Location: Portugal Posts: 405	Let me try explain it in a simple way. For nitrate reduction you’ll need more bacteria. With carbon dosing you’ll give more food to the bacteria colonies thus increasing the bacteria number and they shall consume the nitrates. I use Red Sea NOPOX for Nitrate reduction/maintenance.

07/16/2018, 01:20 PM	#13
Alfrareef Registered Member Join Date: Mar 2016 Location: Portugal Posts: 405	@WHT1014 your doubts went away?

07/16/2018, 06:22 PM	#14
WGT1014 Registered Member Join Date: Apr 2013 Location: Brewerton, NY Posts: 31	No my doubts did not go away...my question was STILL not answered...let me try this...Saturday at 10 am I did a nitrate test. It showed 16... IMMEDIATELY after I did a 20 gallon water change which, BTW is NOT 20% of 75 gallons....at 10:30am, same day, IMMEDIATELY after that WC I checked nitrate again and it was STILL 16...Like I said earlier, not a big deal, forget I asked...

07/16/2018, 06:37 PM	#15
Uncle99 Crab Free Zone Join Date: Sep 2017 Location: Ontario, Canada Posts: 2,906	Just trying to help!

07/16/2018, 06:42 PM	#16
mozelsa Registered Member Join Date: Jun 2018 Posts: 1	Sent from my iPhone using Tapatalk

07/16/2018, 06:45 PM	#17
WGT1014 Registered Member Join Date: Apr 2013 Location: Brewerton, NY Posts: 31	Uncle99, I get that you are trying to help but here's the thing...I'm not asking how to lower my nitrates, as I've said several times, I'm just trying to figure out why water changes are not affecting my nitrate levels at 16...even the "math" that got mentioned didn't help...I get the math and I'm very good at math but STILL I don't have a viable answer to my question which is ok...if no one knows, as I've said already, not a big deal, forget I asked...I'll figure it out sooner or later...