Nitrate Stubbornly High in FOWLR - Help!

[SimonHP]

Hi R2R Community.

I am running a FOWLR system with the following components;

• ClariSea Auto Filter
• Skimmer - has very little work to do
• Carbon & GFO Canisters
• Liverock

I dose alk, Ca & Mg and have the following parameters;

• Alk. 8.4, Ca 430, Mg 135

My problem is stubbornly high Nitrate > 50ppm whilst my PO4 remains below 0.02

I have recently added a biopellet reactor for the NO3 but it has had little effect.

Any advice would be appreciated

 

[lmm1967]

I don't worry about any of that stuff or those parameters in a system with no coral other than PO4 for algae control.

I don't believe vertebrates care about any of that.

 

[daybreaksky]

hi! how much live rock, what test do you use and what are your Nitrites at?

 

[SimonHP]

hi! how much live rock, what test do you use and what are your Nitrites at?

So, the system is about 100g, I have probably 10kg liverock. I use Salifert to test. My frag tank right next to it tests trace NO3 so I'm confident the kit is working.
I wondered whether the very low Phos was inhibiting the denitrifying process given the relationship between the two??
I realise that high NO3 is not so critical in a FOWLR system but I'd prefer to be measuring 10 or less rather than the +50 that I'm getting.

 

[Backreefing]

A deep sand or gravel bed helps . Also a fudge will be helpful. Also bio pellets help to . There is carbon doseing. You could add a second protein skimmer helps . But all of these things take time . Don’t think as soon as you set up bio pellets or a fudge that a week later everything’s good . Honestly the second skimmer is probably the most quick for results but it will get you only so far .
If it were me I would add a deep gravel bed. People hate it but it does look good and is a natural solution for nitrates . Water changes get you a couple days at best ( you probably found out yourself ) .

 

[Backreefing]

I didn’t want to endlessly type. I would go
1 with more skimming
2 deep sand or gravel bed 2-4”
3 carbon doseing. I prefer Vinegar over vodka. Yes vinegar lowers PH but vodka is well known to cause red cyano outbreaks.
4 slack up on the gfo . There’s nothing wrong with .050-.1 . There is a relationship between phosphate and nitrates. If you drive one down the other may rise . Good luck

 

[SimonHP]

Thank you Backreefing. It’s the last point, 4 slack up on the gfo, that I’m most interested in. I have shut down the gfo reactor to try and bring up the phosphates. Do you know of any interesting resources that discuss the impact of nitrate/
phosphate ratio on nutrient management?
I have been running a carbon reactor for several weeks without effect so I think from what I am experiencing that the presence of phosphate maybe required to assist in the consumption of nitrate.

 

[Backreefing]

Generally phosphate should be a little low .05-.1 . Nitrates @10-20 is fine for any animal. But there is a ratio between them ( red field ratio) look it up . The research is already been done .
but watch out for phosphate even a little high vs nitrates. If it goes out of balance that way is a great way to induce red cyano.

 

[Dan_P]

Hi R2R Community.

I am running a FOWLR system with the following components;

• ClariSea Auto Filter
• Skimmer - has very little work to do
• Carbon & GFO Canisters
• Liverock

I dose alk, Ca & Mg and have the following parameters;

• Alk. 8.4, Ca 430, Mg 135

My problem is stubbornly high Nitrate > 50ppm whilst my PO4 remains below 0.02

I have recently added a biopellet reactor for the NO3 but it has had little effect.

Any advice would be appreciated

i would dilute the aquarium water to get the nitrate reading near 10 ppm, where the the reference colors are easier to distinguish. Your system might be at 30ppm or 100 ppm.

Once you discover whether you have high nitrates or incredibly high nitrates, you will be better situated to pick a course of action.

By the way, carbon dosing can take weeks before showing any effect. Your nitrate test will likely not show any change with the color pinned at maximum for the test.

 

[homer1475]

Pretty sure we have debunked the redfield ratio long time ago. Just look at where peoples nutrients are. Not even close to what the redfield ration says it should be.

And the dude has carbon in a reactor(as in GAC), not carbon dosing.

I would start with several water changes to get levels down to a manageable level. The look into carbon dosing, algae reactors, algae turf scrubbers, or even media pure(or similar) media in the sump in a low flow area to grow the bacteria to deal with nitrates.

EDIT:
Missed this was FOWLR. At 50ppm, I wouldn't even worry about it.

 

[Jtimbs]

Chaeto

 

[Radicalrob1982]

Hi R2R Community.

I am running a FOWLR system with the following components;

• ClariSea Auto Filter
• Skimmer - has very little work to do
• Carbon & GFO Canisters
• Liverock

I dose alk, Ca & Mg and have the following parameters;

• Alk. 8.4, Ca 430, Mg 135

My problem is stubbornly high Nitrate > 50ppm whilst my PO4 remains below 0.02

I have recently added a biopellet reactor for the NO3 but it has had little effect.

Any advice would be appreciated

Hi. I would definitely re test with another kit if possible to confirm the readings are true. It seems to me that if your nitrates are that high then your phosphates should probably be higher. Are you using r.o. water?

I run a 20 long nano tank. I have 2 clowns, a coral beauty and a orange spotted goby. I also use about 18 pounds of live rock. I haven't done a water change in 3 weeks and my nitrates are at about 5 ppm and phosphates are barely detectable. I only run chemi pure elite in a small aquaclear hob filter. I do get some algae but not that bad.

I would also check your source water. I had a similar problem in a freshwater tank. My nitrates were insane. I finally checked my tap water and it was green on the test kit for ammonia, which converts to nitrates. Took me forever to find out the source. But once I did I used algone pads and nitrazorb and it helped considerably.

Being a reefer has taught me so much about water quality. I swear If I build another planted tank I'll be using r.o. water and balancing it with r.o. right or another. Tap water is terrible lol

 

[SimonHP]

Hi. I would definitely re test with another kit if possible to confirm the readings are true. It seems to me that if your nitrates are that high then your phosphates should probably be higher. Are you using r.o. water?

I run a 20 long nano tank. I have 2 clowns, a coral beauty and a orange spotted goby. I also use about 18 pounds of live rock. I haven't done a water change in 3 weeks and my nitrates are at about 5 ppm and phosphates are barely detectable. I only run chemi pure elite in a small aquaclear hob filter. I do get some algae but not that bad.

I would also check your source water. I had a similar problem in a freshwater tank. My nitrates were insane. I finally checked my tap water and it was green on the test kit for ammonia, which converts to nitrates. Took me forever to find out the source. But once I did I used algone pads and nitrazorb and it helped considerably.

Being a reefer has taught me so much about water quality. I swear If I build another planted tank I'll be using r.o. water and balancing it with r.o. right or another. Tap water is terrible lol

Thanks for your input RadicalRob. I had the same thought that there should be Nitrate and Phos together. I had used GFO to manage the Phosphates, it probably did that too well leaving just the Nitrate. What I wanted to understand from someone is whether the two need to be present for the Nitrate to be managed by Carbon dosing (Pellets, Vodka, Vinegar). I've now switched off the GFO to raise the Phosphates to see if I can now reduce the Nitrates using Carbon on the assumption that they get consumed together effectively (like tomato sauce on fries lol).
I'm pretty sure the R/O water is good, I use it in a mixed reef aquarium with no ill effect. Also my test kits measure expected results in the mixed reef tank.

 

[Radicalrob1982]

Thanks for your input RadicalRob. I had the same thought that there should be Nitrate and Phos together. I had used GFO to manage the Phosphates, it probably did that too well leaving just the Nitrate. What I wanted to understand from someone is whether the two need to be present for the Nitrate to be managed by Carbon dosing (Pellets, Vodka, Vinegar). I've now switched off the GFO to raise the Phosphates to see if I can now reduce the Nitrates using Carbon on the assumption that they get consumed together effectively (like tomato sauce on fries lol).
I'm pretty sure the R/O water is good, I use it in a mixed reef aquarium with no ill effect. Also my test kits measure expected results in the mixed reef tank.

 

[tehmadreefer]

Thank you Backreefing. It’s the last point, 4 slack up on the gfo, that I’m most interested in. I have shut down the gfo reactor to try and bring up the phosphates. Do you know of any interesting resources that discuss the impact of nitrate/
phosphate ratio on nutrient management?
I have been running a carbon reactor for several weeks without effect so I think from what I am experiencing that the presence of phosphate maybe required to assist in the consumption of nitrate.

Why worry about reef parameters when it’s a fowlr? Lol

 

[Radicalrob1982]

Pretty sure we have debunked the redfield ratio long time ago. Just look at where peoples nutrients are. Not even close to what the redfield ration says it should be.

And the dude has carbon in a reactor(as in GAC), not carbon dosing.

I would start with several water changes to get levels down to a manageable level. The look into carbon dosing, algae reactors, algae turf scrubbers, or even media pure(or similar) media in the sump in a low flow area to grow the bacteria to deal with nitrates.

EDIT:
Missed this was FOWLR. At 50ppm, I wouldn't even worry about it.

For sure. There has to be some huge ammonia source somewhere or not removing them through means of water changes or de nitrating methods. Gac will almost have little to no affect on reducing nitrate. Either the tank is overstocked or the source water is bad. I've never had nitrates that high unless I neglected my tank or had bad water coming in. My tank now is what you'd consider to be overstocked with 4 fish in a 20 long. But with water changes, good source water and reasonable feeding im able to keep optimal parameters and algae at bay. I haven't done a water change in almost 4 weeks and my nitrates are about 4 to 6 ppm.