Why are my nitrates high? And how do I get them to 0

Hey everyone I am trying to figure out why my nitrates are still at 15 ppm I have had the aquarium for 3 years now and I haven't had nitrate problems until a few months ago. My aquarium is 20 gallons and I have about 20 lbs of fiji live rock (getting a little more soon). Also I only have two fish a damsel and a true percula clown and I am definitely not overfeeding. Also I make water changes every 2-3 weeks. I want to develop my aquarium into a reef but there is no way I would even think about it with nitrate this high. Do I need to buy a de-nitrator to get my nitrates to 0? Will my new refugium get the nitrates to 0 its 10 gallons and I'm putting a mud bed in it, live rock, caulerpa, and chaeto.

Here is my water quality measurements:
Ammonia: 0
Nitrite: 0
Nitrate: 15
PH: 8.2
Alkalinity: 9
Specific Gravity: 1.023

 

I would first suspect the accuracy of your test kit. Also a reading of 15 is nothing to be overly worried about. What are you using for filtration? Media needing to be cleaned/changed maybe? What are you feeding and how many time's a day?

 

I am using a coralife super skimmer, Live rock for biological filtration and I'm getting a Aqueon sump for a refugium. I feed my fish brine shrimp every other day. Will my refugium with a deep sand bed, live rack, and macro algae bring my nitrates down or should I get a reactor to remove it I'm trying to bring it to at least 1.0 ppm but hopefully a little lower as I want to start putting coral in my aquarium (mostly SPS and LPS).

 

+1 to this.

 

I personally would not go with a deep sand bed in a fuge. There's no real benefit to them and actually can cause more issues then not. If you do go deep make sure to have the right critters to help maintain it. Especially sand suffers
Otherwise 2" is plenty with some chaeto and LR rubble, will work wonders on maintaining low No3.
Why are you considering MUD? As a general rule macro and LR are not used when using MUD.
What kind of clean up crew do you have? There nothing like left over frozen food to raise your nitrates. Maybe cut down to 1x weekly feedings with the frozen.

 

Okay thanks for the help. I have a blue tuxedo urchin, a few nassarius snails, a (really) small conch, and a tiny sand sifting star. I actually don't know why I was going to use the mud this is my first refugium and I just thought thats what people usually used haha. Is it very difficult to build a refugium? a lot of people have been telling me I should just build it myself because its easy.

 

avoid the mud. IMO it really doesnt do a whole lot more other than increase your price quite a bit. Mud is used often for mangroves etc. Plus you have to replace it frequently or else it too becomes a nitrate factory!

 

+1 i always seemed to have nitrates and could never get them down near 0 i had a 4 inch deep mud bed in my fug (way to deep!)... my next mistake, i didn't change it and after about 16 months it started to be come toxic, couldn't grow a thing in there, and i didn't know why, till someone mentioned my mud bed could be crashing. i pulled rocks from my refug that had black spots on them, and such a stink. at this time i have a bare bottom refug with a couple rocks at the bottom (one layer) and a variety of macro algae. my nitrates are close to reading 0 now
i cant say for sure its removing the mud thats done it, but i believe that had something to do with it. since that stink on those rocks was not good.
at this time i have a urchin in the refuge, the urchin is loving its home its all it can eat buffet.

 

Fuges are not hard to build at all. However there are several ways to add one to your existing setup. How are you planning on hooking this up to your system?

No to the de-nitrator.

 

I plan on hooking it up beneath the display aquarium in its cabinet.