Nitrites/trates both going down during cycle

[siskiou]

Got another parameter question:

 

the main amount of LR has been in the tank for 10 days, now (after having just LS and a small amount of rock in for 2 months), and I had a huge ammonia spike, and subsequent Nitrite spike.

 

Ammonia has been at 0 for several days, and the Nitrites are coming down, now (about 0.8 mg/L atm).

 

I've had Nitrates since early on, and they are coming down right along with the trites.

 

The highest the Nitrates ever measures was 40ppm, but now they are down to about 15ppm, instead of going up as they are supposed to (if I understand the cycle correctly).

 

Could the reason be that I already had a small cycle 2 months ago with the LS and small amount of LR, and that there is an unidentified macroalgae growing in my fuge?

 

Or will the trates go up after Nitrites are at O?

 

Also, I already have a thin brown coating of diatoms going on my LS/LR.

Can this kill the coralline on my 2 month old LR?

 

Siskiou

******

20H

[seabass]

Nitrates at 15ppm is good; do you know what your phosphate levels are? Nitrates can come down by way of algae (especially in a fuge), a skimmer, a DSB, or through water changes. Your nitrites are converted into nitrates, so “usually” you’ll see nitrates rise as nitrites fall.

 

Nitrates will continue to rise after your cycle is complete as wastes and uneaten food are converted into ammonia, then into nitrites, and then into nitrates. The bacteria are so efficient, that the ammonia and nitrites should continue to read almost nothing.

 

I wouldn’t really worry about the diatom bloom; it’s normal and will go away on it own. You can clean the glass and perform normal weekly partial water changes and your coralline should be fine.

[siskiou]

Thanks, seabass!

 

The diatom bloom is quite amazing, coming out of nowhere and having taken over within 24 hours.

We left Saturday morning, with just the first few signs visible, and by the time we got back in the evening, we were shocked when we first looked at the tank!

 

Someone on another formum mentioned that many nitrate test give false results in the presence of nitrites.

 

I guess I'll wait until my Nitrites are at 0 (which should be fairly soon the way they are dropping) and then see what the Nitrate test shows.

 

I shouldn't be adding any snails until everything reads 0, correct?

 

Siskiou

[seabass]

You need to wait until your ammonia and nitrites are zero, but your nitrates should be somewhere under 20ppm (many reef tanks never see nitrate levels under 10ppm). Nitrates are food for macro algae and some corals so it’s not that “bad”. Generally speaking, low nitrate levels are good (I’d keep them around 10ppm or less if you can).

 

Snails can be sensitive to higher nitrate levels, but it doesn’t sound like that’s going to be much of a problem for your tank.

[siskiou]

Thanks!

 

I've been researching snails for the future clean up crew, and am starting to wonder where to find the variety I want (trochus, nerite, cerith, nassarius...).

Most places have just astrea and turbo, and the one on the net that lists more is sold out of almost all of them.

 

Any suggestions where to order snails?

 

Siskiou

[shadofax69]

Hi I was just wondering what kind of substrate do you have in the and what is the grain size. If you have a small grain size it is posible to get anaerobic regions with a shallow sand bed. The anaerobic bacteria obtain their oxygen by stripping it off the nitrate thus producing O2 and N2 which the O2 is used by the bacteria and the N2 bubbles out of the aquarium thus lowering your nitrates

[siskiou]

I have about 1 1/2" of really fine Aragonite sand (size 0, I think), and some coarser stuff on top. The only LS I could find was coarse, so I got a few pounds of it.

 

It adds up to about 2" alltogether.

 

Nitrites are at 0.5mg/L today, so I hope to be nitrite free fairly soon

 

Siskiou

[onthefly]

Hey Siskiou,

 

I think (like shadow was saying) that your getting the DSB effect in your 2" sand bed. Oolic sand (small sugar sized stuff...i.e aragonite) has roughly the same denitrifying power as 4" of the coarser stuff. So, it is possible that your nitrate are coming down because of that. It would take ALOT of macro to being 40ppm of Nitrates down to 15ppm, and if you just have hitchhiker macro...I don't think that would cut it! So I say your sand is doing it's job!!! Check for bubbles (the final product of denitrification) in the sand.

 

Get some cerith or nassarius snails to stir/clean the sand this will keep it from "fouling" like some people claim "WILL" happen to a DSB if left for more than 2 years. I had mine for 5 years with any problems....

[moorediddy]

So if I see bubbles in my sandbed (1-2") that's a good thing? I just started noticing small bubbles and was worried that it was bad. I couldn't figure out how they got there, hah. Now I get it.

 

-moore