please help me figure out where nitrates are coming from!

highergroove

New member
I cannot figure out where my nitrates are coming from. I noticed they were about 80, did a water change and they came back down to 40. Just did another water change and they went back up to 80 after 5 days.

300 gallon tank - < 6 mos old (rock is 15 years old/established). I removed the filter socks awhile ago. I have a 3" sandbed and do monthly water changes. I have a skimmer - feed once per day very hungry fish - 1 1/2" x 1 1/2" Rod's Reef. And I feed 1/2 sheet of Nori (2 large australian stripeys, kole tang, yellow tang, 2 blennies, coral beauty, 3 cardinal fish, 2 firefish).

Could it be the Nori? I did buy some organic for the last 3 weeks and just went back to the plain old toasted Nori (no additives). I would think 1/2 sheet is not too much and the fish eat it right away

Also, I suspected that it may have been coming from Calcium Reactor - I was running it with no CO2 for a few weeks. But this weekend - I started it back up and topped off with some fresh media thinking any denitrifying bacteria would be killed off with the 6.5 pH. However, with a 10% water change and the startup of the reactor, I find it hard to believe it jumped up 40ppm in 5 days. The pH is indeed 6.5 inside as I have a probe.

I checked the source water and the nitrates are 0.

What do you think I should eliminate first as the likeliest culprit? If I move away from the regular Nori and go to organic Nori? Change the media in the calcium reactor?

What should I do to remove them now? Do any of the products out there work? I'd rather not buy another reactor if I can get away with a filter sock for now or a liquid supplement. Which ones work best? I heard some tend to kill clams...

Thanks in advance for all your help. So frustrating.
 

bertoni

Premium Member
That level of nitrate is safe for the fish, so you could ignore if the tank doesn't have any corals.

If there's no more artificial biofiltration media, I suspect the food is the source. Better skimming might help. Reducing feeding might be appropriate, too. Whether the fish eat the food or not is not critical. What goes in, mostly comes back out, and with about the same energy content.
 

rfgonzo

New member
I will assume if nitrates were at 80 and you brought them down to 40 you did 50% water change? You said you do a monthly water change, at what %? How long do you leave the Nori in your system, I know you said the fish eat it right away but is there any left in the clip? 6.5 PH? Is your probe calibrated properly? Sorry last question, but what is a while ago when you removed the filter socks? Don't mean to ask so many questions but trying to get an idea of what's happening.
 

highergroove

New member
I DO have coral in the system - quite a number of small frags that also don't seem to be doing great - not bad - just not real great.

The pH probe is calibrated - it is a Neptune Apex Gold system so it is the Pro version too. pH is 6.55

As far as Nori in the clip - there could be a tiny bit - my starry blenny usually tries to get every last morsel not tied down but I would say there is a small amount that is the clipped portion.

I skipped the Nori today and also turned off the Reactor until I can change the media - anyone think that it is definitely NOT the issue? I'd love to keep the media....

As far as removing the filter socks -about a month ago (NTW - do most people skip these? They made a custom area in my sump for them and my boyfriend insists they clean the water well and the guys who made it think it captures food but we don't clean them daily and then when we take them out we don't wash them for days/weeks - seem like more of a hassle to me and I always thought they created nitrates as they have surfaces for bacteria - like bioballs)

I will trun up the skimmer too - definitely doesn't seem to be getting as much foam as usual.
 

bdare

Salty Dude
Premium Member
Do you run a skimmer or GAC? Both of these help remove organics before they become nitrates. A fuge with macro algae?
 

rfgonzo

New member
Filter socks are only beneficial if you properly maintain them. If you don't clean them on a regular basis they will become a nitrate factory.
 

highergroove

New member
Thanks everyone,

I have some chaeto in my refugium - I had a bunch and read it can re-release phosphates so I harvested a bunch and now growing a small ball again - maybe that could be partly why although I did that a few weeks ago as well so it doesn't seem to be responsible for the last week spike.

not really any dead spots that I can see except maybe along the back wall under rocks but I have 6000GPH plus a Vortech MP60 going so it should be moving everything. (want that new Maxspect Gyre flow)

Going to experiment with a few things, one at a time - Calcium reactor is back on for now.

Anyone know of a high resolution Nitrate kit ? my API isn't going to help much.
 

bertoni

Premium Member
The Salifert kit might be a bit better than the API. The PinPoint nitrate meter seems to be reasonably accurate, but it is very costly.
 

Ruffoj926

New member
I would just stay relaxed and not make any drastic changes. Keep doing generous water changes, reduce feeding as much as possible, and install a very powerful skimmer if you can. Whatever the source of nitrate is, it is not magic; it can't last forever. It should go away on its own if you reduce feeding.

You have a lot of fish in there and a good skimmer will go a long way to remove dissolved organically before they turn into nitrate in the future.
 
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