High nitrate low phosphate

[jakem42]

My tanks been running about 9 months now and I have an issue with high nitrates and low phosphates. Nitrates are around 65 and my phosphate is .1 I’ve tried chaeto, dosing carbon and have my skimmer running 24/7 but my nitrate has not gone down at all. What should I do? Raise my phosphates to the red field ratio and then try to lower both? I do have some corals in the tank 2 Duncan’s and a few hammers. Will raising the phosphate kill them? Thanks for the help.

 

[gbroadbridge]

My tanks been running about 9 months now and I have an issue with high nitrates and low phosphates. Nitrates are around 65 and my phosphate is .1 I’ve tried chaeto, dosing carbon and have my skimmer running 24/7 but my nitrate has not gone down at all. What should I do? Raise my phosphates to the red field ratio and then try to lower both? I do have some corals in the tank 2 Duncan’s and a few hammers. Will raising the phosphate kill them? Thanks for the help.

Water changes are by far the simplest method of lowering nitrates.

If you have a tank > 120 gal you could consider starting carbon dosing with vinegar.

 

[jakem42]

Water changes are by far the simplest method of lowering nitrates.

If you have a tank > 120 gal you could consider starting carbon dosing with vinegar.

My tank is 240 gallons and I’m on a well so it’s hard for me to do big water changes

 

[PocketGoose]

Have you determined the source? What is the feeding/livestock situation?

Where is your water coming from?

 

[jakem42]

Have you determined the source? What is the feeding/livestock situation?

Where is your water coming from?

I haven’t yet. I feed twice a day once in the morning and once at night. Livestock is 2 clowns, 3 tangs, 5 chromis, 2 anthias, a yellow wrasse, possum wrasse and a diamond goby

 

[jakem42]

Have you determined the source? What is the feeding/livestock situation?

Where is your water coming from?

Water is from a well with a 4 stage rodi unit

 

[gbroadbridge]

My tank is 240 gallons and I’m on a well so it’s hard for me to do big water changes

In that case you could start on vinegar dosing.

This thread discusses it.

Vinegar Dosing questions.

Hi everyone, Right now I have high nitrates (around 50ppm) and low phosphates (around 0.1ppm). The phosphates might be a false reading since my tank is now filled with green hair algae (which Ive been trying to remove). I remove them manually when doing water changes weekly, and they still grow...

www.reef2reef.com

 

[Randy Holmes-Farley]

I agree that carbon dosing, or getting more chaeto to grow is a fine plan.

Did the chaeto grow but not lowing nitrate enough, or did it not grow?

 

[Dburr1014]

Wait... Po4 is 0.1, why do you think this is low?
NO3 at 65 can be done with water changes.
I wouldn't mess with po4. IMO, it's a perfect number.
240 gallon is a big tank but how big of a change can you do?

 

[jakem42]

I agree that carbon dosing, or getting more chaeto to grow is a fine plan.

Did the chaeto grow but not lowing nitrate enough, or did it not grow?

The chaeto didn’t do anything it would die after about 2 weeks

 

[jakem42]

Wait... Po4 is 0.1, why do you think this is low?
NO3 at 65 can be done with water changes.
I wouldn't mess with po4. IMO, it's a perfect number.
240 gallon is a big tank but how big of a change can you do?

I’m not trying to lower po4 but I think my nitrates are a problem. I can do around a 35 gal water change.

 

[Randy Holmes-Farley]

The chaeto didn’t do anything it would die after about 2 weeks

Then either it wasn't in good shape when added, isn't getting the right lighting/flow, or you are missing important trace elements such as iron and manganese.

 

[jakem42]

Then either it wasn't in good shape when added, isn't getting the right lighting/flow, or you are missing important trace elements such as iron and manganese.

This is the light I’m running at the moment. Others said they had good luck with it but maybe it’s not enough?

 

[Dburr1014]

I’m not trying to lower po4 but I think my nitrates are a problem. I can do around a 35 gal water change.

That's about 15% of your water volume.
Maybe get a brute can and you can double it.
If you do get cheato to grow, it may pull down po4 so you may need to dose that eventually.

 

[jakem42]

That's about 15% of your water volume.
Maybe get a brute can and you can double it.
If you do get cheato to grow, it may pull down po4 so you may need to dose that eventually.

I have a brute at the moment but I can’t make much more than 35 gallons at a time without over taxing my well

 

[jda]

Chaeto is going to struggle with no3 of 65. It grows better with lower residual nitrates - a cruel joke of nature. Once you get your no3 lower, try it again. You are going to need to change water or add iron once it starts growing.

If you have sand and it is undisturbed, about 6-12 month mark is where is can start to develop anaerobic bacteria that convert no3 into nitrogen gas. 2-3 inches is the minimum. Rock can do this too, but if it was dead/dry rock, it can take years for it to function removing nitrates.

Carbon dosing can help. It will take some time and commitment. Ramp up slow.

Second skimmers can help too. I run multiple on all of my tanks.

 

[jakem42]

Chaeto is going to struggle with no3 of 65. It grows better with lower residual nitrates - a cruel joke of nature. Once you get your no3 lower, try it again. You are going to need to change water or add iron once it starts growing.

If you have sand and it is undisturbed, about 6-12 month mark is where is can start to develop anaerobic bacteria that convert no3 into nitrogen gas. 2-3 inches is the minimum. Rock can do this too, but if it was dead/dry rock, it can take years for it to function removing nitrates.

Carbon dosing can help. It will take some time and commitment. Ramp up slow.

Second skimmers can help too. I run multiple on all of my tanks.

Didn’t know chaeto didn’t do well with higher nitrates that’s good to know. I have a 2 inch sand bed but I would only say it’s completely undisturbed as I have a goby that likes to sift through the sand. I Did start with dry rock so that may be an issue I have too? I’ve tried carbon dosing with no effect how long should I expect to wait until I see a change?

 

[Randy Holmes-Farley]

Chaeto is going to struggle with no3 of 65. It grows better with lower residual nitrates - a cruel joke of nature

What is the evidence or rationale for that?

 

[Dan_P]

My tanks been running about 9 months now and I have an issue with high nitrates and low phosphates. Nitrates are around 65 and my phosphate is .1 I’ve tried chaeto, dosing carbon and have my skimmer running 24/7 but my nitrate has not gone down at all. What should I do? Raise my phosphates to the red field ratio and then try to lower both? I do have some corals in the tank 2 Duncan’s and a few hammers. Will raising the phosphate kill them? Thanks for the help.

How long did you try dosing? what your maximum dose? How fast was the Cheato growing?

 

[jda]

If you ever dosed any algaecide like Vibrant, AlgaeFix, etc. then people are struggling to keep chaeto even long while after not dosing anymore.

I have seen too many tanks, including some of my own, with macro struggling in the 25-50 ppm of no3 range and then full out struggle over 50ppm. The proverbial "I have 100 nitrate and no algae" type of deal. po4 plays into this too.

Carbon dosing is a long term, daily thing. Go slow, keep at up and slowly raise the dosage. Your skimmer cup should be the first thing to watch. The skim mate should change, smell totally foul and rancid with hugely increased production. When all of this starts to happen, freeze the dosage. Don't keep raising it. It will do the work over time. There are many articles on this that you can read. I used just plain old sugar in a FOWLR with good success and after I got the nitrate down to about 20-25 some GHA started to come back... then I got it down to like 1-5 ppm and the coralline started to take over again. Vinegar, vodka, sugar and ethanol all have supporters and also detractors, but in the end, they all work. Growing bacteria with organic carbon does not appear to use orthophosphate, which is the only kind that we can test for. It has to use other kinds or else organic tissue cannot form, so pay close attention to your corals, if you have any, since they likely use these other kinds too. Just remember that high tide lifts all ships, so other types of things will grow more too.