Nitrate Confusion

[Interested]

Hope someone can help. I'm as confused as all get out. I have read here and other articles and talked to people at other sites about controlling nitrate levels. Everyone says the same thing. Partial water changes and vacuum the substrate. My tank is about 2 months old but I cannot seem to get the nitrate level down below 40ppm. I have been doing 20% water changes once per week and vacuuming the substrate for the last 3 weeks. Then today a guy at a LFS says that I should only do water changes once per month and that I should never, under any circumstances vacuum the substrate (I'm using aragonite). Here's the tanks info. I hope I haven't been wasting my time. btw, I only do 20% water changes because it takes so long to get 30 gallons of RO/DI water and storage space is limited. I only have 1 container.

135 Gallons
RO/DI water
PH = 8.2
Amonia = 0
Nitrite = 0
Ntrate = constant 40ppm
Salinity = 1.023
Two Fluval 404 w/no media
Protein Skimmer

Thanks in advance for any advice. If I'm headed in the wrong direction please don't hold any punches.

 

[steve-s]

While I personally agree with not vacuuming the substrate the amount and frequency of the water changes is directy related to need. In your case you need to do them more often and weekly. The tank is quite young still and although it can cope with NH3 and NO2, the anaerobic/anoxic bacteria that convert nitrate so it can safely leave the system most likely are in their infancy (mass wise) of haven't even formed yet. It can take quite a few months before NNR will occur. Just keep up with the weekly water changes and only feed every second day. Just be sure there is always some type of Nori or other grazing food for the tang. It will start coming down, you just need to be patient a few more months. For your current bioload the amount of rock you have is fine but if you decide on addition stock (waste producing) I would suggest another 50-80 lbs.

FWIW, I would seriously suggest returning the anemones. A 2 month old tank is far too young for such a delicate invertebrate and should only be housed in a well established tank (1+year)

Cheers
Steve

 

[jaiden]

Nitrates will be dropped by macro algae and/or a dsb (which you can't vacuum)

 

[Interested]

OK I'll leave the substrate alone and continue the water changes.

Thanks a bunch for the replies. Sites like this are really a great help.

 

[jaiden]

What kind of substrate do you have? if it's not sand, you should vacuum it. if it is, leave it alone.

also, how much are you feeding?

 

[Interested]

jaiden, I have aragonite for substrate. Currently feeding every other day just as much as fish will eat in a couple of minutes. The Tang gets seaweed, Damsels get flakes. I hand feed the anemone's frozen shrimp.

 

[indy]

How deep is your sandbed? NNR takes a little more depth to get a good anaerobic region. Don't vacuum it as it will disturb your layers. Also, any kind of cleanup crew?

 

[Interested]

The sandbed is a little less than 3 inches. I'm mostly interested in removing the top layer of algea that covers it That's one reason why I vacuum. If I don't vacuum and eventually get the Nitrates under control, will that algea dissappear?

 

[steve-s]

NNR will still occur through a shallow sand bed if the grain sizes are small enough. Anoxic regions are just as efficient at converting nitrate. Given the 120 lbs of LR the only thing you need is time.

The algaes will clear up on their own but a clean up crew would still be a plus. It really depends on your source water primarily. RO/DI or tap?

Cheers
Steve