Nitrate still High

[dan_chng]

Hi everyone,

I am back again with still the same problem of high nitrates in the region 0f 50-80 ppm. I have tried all the suggestion of my last posting and still no help. Lately 2 of my fishes just died a clown tang & a fire clown (looks healthy, eating then one day, start to lay on it side and the next day, kaput) Water test all seems normal NH3, zero, NO2, zero except for NO3.

Anyway back to my problem, I am now considering of adding a Bio-denitrator to help solve my NO3 problem. Anyone out there have experience using them? I am looking at Sera Denitrator. How best to set it up as the manual shows that using it with a canister filter, but my setup is a sump with overflow. I am also using a Protien skimmer and UV sterilizer. Thanks

 

[ChrisRD]

I have tried all the suggestion of my last posting and still no help.

It will be much easier for us to provide you with useful feedback if you can be more specific about what the current state of your system is. For example, how much live rock do you have in the system?
Are you using a deep sand bed (DSB) in the main tank or a refugium?
Have you tried growing macro algaes for nitrate/phosphate export (generally this is done in the refugium/sump)?
Is your skimmer working well (ie. are you seeing daily skimmate production)?
Are you still using plastic biomedia or did you remove it?

 

[dan_chng]

It will be much easier for us to provide you with useful feedback if you can be more specific about what the current state of your system is. For example, how much live rock do you have in the system? (Dan_chng - I have about 60 Kg of live rocks)
Are you using a deep sand bed (DSB) in the main tank or a refugium? (Dan_chng - I am not using a refugium but a DSB about 5 inches)
Have you tried growing macro algaes for nitrate/phosphate export (generally this is done in the refugium/sump)? (Dan_chng my sump has no Macro Algaes)
Is your skimmer working well (ie. are you seeing daily skimmate production)? (Dan_chng - Yes my skimmer is producing though not a lot, how much impact does a skimmer play in reducing NO3?)
Are you still using plastic biomedia or did you remove it? (I have removed my biomedia)

Dan_chng
Here are the specs of my tank
-80 Gal Main tank with overflow
-20 Gal Sump
-Protien Skimmer
-UV Sterilizer
-1 x Blue Lamp
-1 x White lamp

Live stock
-6 different types of soft & hard corals. They are all doing fine
- Left with 3 fishes, 2 x 1 inch damsel, 1 x 3 inch Coral Beauty
- 1 x Cleaner Shrimp
- 1 x Anemone
- 2 x Feather Duster Worm
- 1 x Tube Anemone
- Substrate, Coral Sand 5 in
- Live rock 60 kg

I am at wits end on high NO3 and as such want to try a denitrator. I need advice on how best to use a sera bio-denitrator.

 

[Len]

As for coil denitrators, my opinion is they have no place in reef tanks. They sometimes work a little, but a deep sand bed does the same thing, and more naturally I might add. How deep is your sandbed?

If you aren't experiencing excessive algae blooms, don't worry about the nitrates. It's not immeidately toxic to most organisms.

 

[ChrisRD]

What are you using for source water? Have you checked your source water for nitrates?

BTW, I agree with Len...

 

[dan_chng]

Len & ChrisRD thanks for the input.

1. My sand bed is about 5 inches
2. My water source is very close to RO (7 stage filtration) and I have tested it for NO3 close to zero
3. There is hardly any algae bloom, very minimum.

Why is it when I read mosy books and forums, it is recommended that NO3 should be lower than 10ppm and if it gets too high even corals will not thrive and tangs will stop feeding. Is this right?

 

[ChrisRD]

How are you testing nitrates? Have you been using the same kit all along or have you tried others? Does your LFS do water testing? If so, that would be a good double-check on your numbers...

Also, the lack of production from the skimmer probably isn't helping. The more your skimmer pulls out, the less ammonia/nitrite there is availabe for the aerobic bacteria to convert to nitrates, so yes , indirectly, strong skimming can help with nitrate control.

You could try putting a light over the chamber in your sump you had been using for the biomedia (which I'm assuming is now empty) and start growing some macro algaes in there. They can help soak-up excess nitrates and phosphates. Set the timer on the fuge light so that it functions at opposite times of the main tank lighting. Do a search on "reverse daylight" for more details on that.

It's possible that your sandbed isn't doing much in the way of denitrification just yet and may need more time to mature. Once mature, the live rock and sandbed should provide a lot of denitrification. In some new tanks this effect seems to kick-in late, and then happen suddenly (ie. your nitrate levels climb for a while and then just drop-off). Personally I've never experienced that, but I've heard of that happening to others.

In the meantime, you might do a few large (like 50%) water changes back-to-back to get things headed in the right direction...

HTH