What nitrate level is actually harmful?

[jasonrusso]

Since the beginning of the year, I have been paying close attention to my nitrates. Mainly because my fowler tank was 100+. Maybe close to 200. I would have some sudden deaths (usually lionfish which are sensitive to high nitrate). I've since lowered that tank to 5ppm with a sulfur denitrator.

My reef tank has a nitrate reading of around 20-25ppm on Salifert (what's the error %). Now, let me stress that I don't have any problems. No algae, my snails and crabs are fine. My pistol shrimp is fine, corals all look great (some sps could be better, but BTAs, zoas, softies are huge).
I did try to diy a sulfur denitrator for the small reef tank, but it didn't really work.

Now, is 25ppm really an issue? I read that 40ppm is when chronic nitrate poisoning could become an issue. Lions don't like over 40. I'm planning on putting some purigen in my reactor with the phosguard. The tank is a 34 gallon C-130, so space is limited.

 

[GoVols]

This helped me, when it came out

Tank Parameters Of Some Masters

Tank Parameters Of Some Masters To this day one of the most frequently asked questions I get, and actually that many “old time hobbyists” get is “How do I get rid of the algae in my tank. My first question then is “what are the parameters of your tank’s water? Invariably the answer is my tank’s...

www.reef2reef.com

All over the place from low to 54ppm, but high might effect certain fish???

 

[jasonrusso]

This helped me, when it came out

Tank Parameters Of Some Masters

Tank Parameters Of Some Masters To this day one of the most frequently asked questions I get, and actually that many “old time hobbyists” get is “How do I get rid of the algae in my tank. My first question then is “what are the parameters of your tank’s water? Invariably the answer is my tank’s...

www.reef2reef.com

All over the place from low to 54ppm, but high might effect certain fish???

I'll have to read the whole thing, but it is the fish's health that is most important to me. Like I said, I know lions don't like high nitrate. I assume most fish get a chronic poisoning eventually, but I saw my new lion (a new fish after my old lion suddenly died) start to turn red and wheezing due to lack of oxygen. I started dosing prime to detoxify the nitrate and within 48 hours he was back to normal again. That's when I really started to dig in.

 

[GoVols]

I'll have to read the whole thing, but it is the fish's health that is most important to me.

I hear ya, and tagging along....

don't think my Achilles could take high nitrates either.

 

[SeaDweller]

I hear ya, and tagging along....

don't think my Achilles could take high nitrates either.

OP. I’m glad you finally got the reactor working. Took some time though huh? Mine is keeping my tank with 35 fish and heavy feedings at 1.0 ppm. I do have some algae but it doesn’t bother me as all else is healthy.

To answer your question I had my NO3 at 250-300 ppm, remember? And all was fine. Govols- my Achilles did fine in that system, and my biggest indicator that something was wrong was my desjardini lost its color, which has now come back obviously.

 

[Rich Klein]

What is your PO4?

 

[jasonrusso]

OP. I’m glad you finally got the reactor working. Took some time though huh? Mine is keeping my tank with 35 fish and heavy feedings at 1.0 ppm. I do have some algae but it doesn’t bother me as all else is healthy.

To answer your question I had my NO3 at 250-300 ppm, remember? And all was fine. Govols- my Achilles did fine in that system, and my biggest indicator that something was wrong was my desjardini lost its color, which has now come back obviously.

It took about 4 months, but I was trying to lower 210 gallons. It takes a long time to get all that water through, lol. Since I got the numbers down (sometime in June), I've noticed the fish are much more active. I also have a bit of a cyano issue because of the vast nutrient imbalance. I don't really care, I don't have any corals in there.

 

[SeaDweller]

It took about 4 months, but I was trying to lower 210 gallons. It takes a long time to get all that water through, lol. Since I got the numbers down (sometime in June), I've noticed the fish are much more active. I also have a bit of a cyano issue because of the vast nutrient imbalance. I don't really care, I don't have any corals in there.

Glad to hear buddy, I think your levels now of 5 are perfect. Regarding the cyano, try chemiclean or dosing a bacterial supplement. I’d recommend you do some water changes as well, just to spruce things up.

 

[Randy Holmes-Farley Verified Community Expert]

Here's a copy and past of my comments on fish toxicity to nitrate from one of my nitrate articles

Nitrate in the Reef Aquarium - REEFEDITION

Nitrate is an ion that has long dogged aquarists. It is typically formed in aquaria through the digestion of foods, and in many aquaria it builds up and can be difficult to keep at natural levels. In the past, many aquarists performed water changes with nitrate reduction as one of the primary...

www.reefedition.com

Fish, it seems, are not very sensitive to nitrate. Most researchers find little toxicity. One group that studied a variety of species of fish larvae report:

“Judging from its effect on 1st-feeding, unionized NH3 is a potential hazard in the rearing tank; NO2– and NO3– are nontoxic at levels likely encountered in practical marine fish culture.”

Still, many hobbyists report that their fish appear less healthy when they have allowed nitrate levels to get excessively high (over 50 ppm). Whether that is actually due to nitrate or something else about the water that is coincident with the nitrate rise is unknown.

 

[jasonrusso]

Glad to hear buddy, I think your levels now of 5 are perfect. Regarding the cyano, try chemiclean or dosing a bacterial supplement. I’d recommend you do some water changes as well, just to spruce things up.

I'm not sure if I want to dose chemiclean. Now that everything is going so well I don't want to mess with bacteria. I'm mixing phosguard in with my carbon. The cyano isn't hurting anything anyway.

 

[Crossfire]

The WWC teams keep their nitrates at around 20ppm. They said so in a BRS video, so if they keep it at 20, I'm sure it's fine.