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View Full Version : My nitrates won't come down?


padgett152
05/14/2009, 11:17 AM
I have an established(3 years) 75 g FOWLR tank. I have 2 fish in it. My water parameters are excellent with the exception of nitrates. I added a refugium over 2 months ago hoping this would help control the phosphates and the nitrates. Phophates are 0. Nitrates are over 160 ppm. I have done large 40% water changes the past 2 weeks and nothing seems to be working. My top off water has excellent parameters, 0 ppm nitrates. My DT has 125 lbs of live rock with a 5" DSB, my fuge has a 5" DSB as well. My skimmer working well, removing a cup of skimmate every 2-3 days. Any suggestions?

jenglish
05/14/2009, 12:19 PM
Look into a denitrator or vodka dosing. I am not an expert on either but their is a wealth of info around the site from folks that are.

Ehaze
05/14/2009, 12:52 PM
+1 sulphur denitrator

Michael
05/14/2009, 01:02 PM
are you 100% sure they are 160? if so i understand your frustration, i can only say reduce feeding, dont allow uneaten food to lay about in the tank and even though water changes wont be an immediate cure, lots of little frequent changes and ensuring the water is totally pure will definately reduce those trates. i wouldnt consider vodka at the moment, your fish only and they wont mind too much and once you start its a full time hands on duty to illiminate nitrates with vodka. imo its best to get back to basics and clean pure water and no detritus is the best method.

Superstretch18
05/14/2009, 01:12 PM
Have you tried a different test kit? It may just be that your reagent has expired. Take a sample of water to a LFS and see if they can confirm your readings.

It's also possible that your substrate and rock are acting as a nutrient sink. If the levels were ever off the charts for a sustained period, calcium based substrates can absorb nitrates (and other substances) and leach them slowly back into the tank. I've seen this happen in the past and the only recourse was to slowly change out the substrate with new.

Before taking that on, you can test it by taking a cup full of your sand and putting it in a bucket of freshly mixed saltwater. Test nitrate at the start and then again in a day or two. That will tell you if you have a problem with nitrates leaching back from your sand...

scottwhitson
05/14/2009, 01:41 PM
I agree with trying another test kit before you do anything else.

letik
05/14/2009, 01:48 PM
I had my nitrates at around 80-90 before with all other excellent parameters. I added chaeto to my eheim compartment and partially removed bio cylinders. Now they are 5. Find out the reason why your nitrates are so high! Don't buy those $$$ denitrators..
Less feeding definitely helps!

See if you have good flow thru the live rock and that there is no detritus in your refugium. You can also install a small direct pump that blows a strong current at your life rock for 1 hour/day to blow off the particles of food. I have rio 600 that works for 2 hours and sends 250 gal/hour jet into my live rock and can see clouds of particles coming from every hole when it turns on.

pic of rio behind my liverock
http://reefcentral.com/gallery/data/500/216312IMG_0318sm.jpg

All other great params mean that your cycle is efficient up to the nitrates conversion. If it's nitrates leak make sure that you're not adding more to it. If you have some old sponges in your filter dump them.

I would also look into adding some Nassarius Snails.
In any case it took about 1-2 months to lower my nitrates.

Make sure you do a water changes after you do the cleaning.

Don't get upset, small gradual changes and they will go down!

r-balljunkie
05/14/2009, 05:59 PM
I swear by my denitrator. Its just my old calcium reactor I shut down some time ago. I bought some sulfur media for 20 bux. I know there are a bazillion gimmick products and add ons, but my tank has never looked better. I am not a gadget freak, and try to spend as little as possible…I try to minimize the amount of crap I have plugged in.

This was the best 20 bux I ever spent.

I am not a huge fan of DSB, especially in the tank, or fuge. I am a huge fan of RDSB, and think it has its merits. For the tank, its just an aesthetics thing for me. For the fuge, I think it becomes a detritus trap. My tank did better after I pulled mines.

Good luck, any direction you head. That is what’s great about public forums, ask 1 question get 5 different responses!!

c

letik
05/14/2009, 06:21 PM
r-balljunkie, you can check my setup and see if you can go with something even less than what I have. I'm the guy of simplicity and love effective approaches.

http://picasaweb.google.com/aletik/Hexagon#

denitrator and using sulfur is cool! I wated to build a mini one but based on the research I did when my nitrates were 90, I saw that it gradually lowers PH and could leak some sulfur substances into the tank if the flow is higher then recommended.

What I mean to say not even looking at the cost and nuking the symptom instead of finding the problem is that it adds another variable to the system that needs to be monitored. Adding chaeto has its disadvantages, but doesn't add more variables to the system.