New cycled aquarium - nitrate question

[Freddy Twotimes]

I am cycling a reef aquarium with live rock. I am using the AP test kits.

55 gal
192 watt Coralife lunar aqualight
Coralife skimmer [for up to 60 gal. tank]
66 lbs of live rock
4" deep sand bed
UV sterilizer
2-maxi jet 1200's
1 Whisper filter [330 GPH, no filters; I use this for flow, carbon and future poly filters if necessary]
I have not been running a light to eliminate bad algae growth due to the long cycle time.

In my current situation I can not do a sump, I cannot do a refugium and have little to no room for any more water flow devices. I am planning on a soft coral tank - begginer corals with 2 fish and a shrimp.

I have been cycling for 3 months and this past week I have achieved 0 Ammonia, 0 Nitrite, 440 Calcium, 8.4 PH...but the Nitrate was 160+.

I did a 100% water change, waited two days and tested; the Nitrate went down to 80. I did another 50% water change and tested, waited two days and tested; Nitrate went down to 20.

I waited a week, the Nitrate went up to 30, I did another 50% water change and nothing changed at all. Everything else is perfect but the Nitrate is still at 20.

Is it normal to see these types of Nitrate issues when everything else is so perfect? All I can do is monitor it and do weekly water changes until I get it under control but how much water do I have to change to get this under control? Will the sand digging snail varieties help reduce Nitrate?

My big concern is hair algae. Any comments will be appreciated

PS

The water I use is RO from a local water store. The Nitrate is 0 and the Phosphate is 0.1 from the source.

[tike]

Hmmmmm...this is interesting. It seems it took your tank awhile to cycle. Normally it takes 2-4 weeks for a tank to fully cycle it is a bit odd ( but cetainly not out of the question!) that it took so long. As for the nitrate problem I to had them for a long time and only got rid of them when I removed my deep sand bed. Since I went BB I haven't had any problems keeping my nitrate really low or at 0.

HTH

[Freddy Twotimes]

There is a lot of controversy between DBS and not, I have a sandbed that does not exceed 4" so I am hoping that I can make it work.

[leebca]

Is it normal to see these types of Nitrate issues when everything else is so perfect? All I can do is monitor it and do weekly water changes until I get it under control but how much water do I have to change to get this under control?

Nitrates are the result of the nitrification process and are 'normal.' You should read this: Nitrates - Origin & Controls

Some observations:
The fact that your tank took so long to cycle indicates the bacteria were either a bit slow to gain a foothold or that there was an excess of decaying matter or both. I tend to favor the decaying matter. The condition of the live rock would be suspect (as being a source of organic decaying matter AND/OR not being live). BUT don't assume the tank is ready just because the cycle is concluded. The tank is still going through changes and hasn't matured yet (see below).

Water changes will of course only cut the nitrate level by the percentage of the water change. As long as ammonia is being produced (from decaying, rotting organics, or fauna wastes) the nitrates will follow. But why the live rock isn't properly processing it could just mean: 1) there isn't enough live rock; 2) the rock isn't as 'alive' as it should be; 3) there is too much organics for the rock to handle the excess nitrates (and two more sub-reasons: a) because the rock itself is curing/having die off; or b) too much organics in the aquarium); or 4) any combo of these.

1) I would have targeted about 100+ pounds of live rock.
2) Are you sure it is live rock? What is Live Rock, Anyway?

For a reef aquarium, a lot of live rock isn't mandatory (assuming the aquarium won't have to support a lot of waste producing animals (fish, shrimp, crabs, snails, etc.)).

3)a) Is it for certain the live rock had been properly cured before its use. Maybe some die-off is still going on there?

3)b) I would not have chosen such a skimmer. That is, I would have chosen a skimmer suitable for a 125+ gallon aquarium. Always at least a factor of two should be the target. As long as there are sufficient dissolved organics in the water, the bacteria will continue to produce nitrates from that ammonia source.

Even though a refugium or sump aren't possible, some small hang-on refugium may be sensible to cultivate Chaeto.

The 'bad algae growth' is symptomatic of the immature aquarium, going through biological and chemical adjustments (that are not being tested). I wouldn't assume anything is wrong with the aquarium until these things become reduced to being no longer a bother and the aquarium matures. See: The Mature Aquarium. Still you can take some steps noted above and in the references to control the nitrates.

[sihaya]

I think Lee says it all. And it's a great point about the live rock. I've seen some pretty sad looking "live" rock in some LFSs... so much dead and decaying stuff it's almost scary.