Natural Nitrate Reduction

[FLARGUE]

Hi everyone,

 

I just started a 20 gallon tank with live rock (21lbs) and live sand (1/2inch bed)

I've been testing my water parameters and have finally hit 0 ammonia, 0 nitrites, and 5ppm nitrates. When I tested the water a couple days ago, the nitrates were around 40ppm, so i'm wondering how that significant drop may have occurred. Can nitrate levels reduce naturally without water changes?

Additional info: ive been keeping the lights off. HOB 20 gal filter with filter floss, eHeim 2213 canister with just a little filter floss on top, and a powerhead. Temps kept at 78*

 

Thanks!

[Telathas]

Are you cycling the tank? If you are, are you dosing ammonia? The fact that you went from 5 ppm nitrates to 40 ppm means that something is producing ammonia, whether it is fish poop, decaying matter, or you dosing ammonia for your cycle. From what I understand, there are a few natural ways of reducing nitrates. You can put something into your tank sump like chaeto which will absorb nitrates in order to grow (as long as you provide adequate lighting). A protein skimmer also helps to keep nitrates down by effectively skimming the proteins out of the water through the use of bubbles. You can also reduce them by performing water changes or just finding the source of the ammonia and reducing it or eliminating it completely.

[FLARGUE]

Yes i dosed with ammonia from Ace Hardware following some directions online. I forget the exact amount but it was maybe 3ml? The tank should now be cycled, but i was curious as to why my nitrates dropped so significantly without water changes, protein skimmer, or chaeto.

[Telathas]

3 minutes ago, FLARGUE said:

Yes i dosed with ammonia from Ace Hardware following some directions online. I forget the exact amount but it was maybe 3ml? The tank should now be cycled, but i was curious as to why my nitrates dropped so significantly without water changes, protein skimmer, or chaeto.

Oh, I might have misread the original post. So you're saying you tested your water a couple of days ago and had a reading of 40 ppm and you did a test recently and tested 5 ppm? Do you currently have an algae bloom in your tank? If you have only dosed ammonia the one time, I think what may be the cause is that your nitrifying bacteria has consumed all the ammonia, converted it to nitrites, then to nitrates, and the algae has used that nitrate to grow. Without continuous dosing of ammonia, your nitrifying bacteria will not be able to produce more nitrates, hence the low readings. Someone else can chime in as I'm not too knowledgeable about nutrient export in saltwater aquariums but that's my best guess as to your weird test readings.

[MockandRoll]

I would guess one of your test results is wrong. Which kit are you using?

[FLARGUE]

Yeah it's a strange result and I don't have any algae blooms either.

I've been using the API saltwater test kit. It comes with the test tubes and droppers. I think you're right that a test was wrong, because i just retested and it showed 5ppm nitrates again

[Clown79]

As far as I know it takes more than 1 day of dosing for the tank to cycle.

 

@seabass shared this the other day.

 

It's for fishless cycling: dosing ammonia and bacteria

 

It explains exactly what you need to do

 

http://www.drtimsaquatics.com/resources/fishless-cycling

[seabass]

Live rock can support some denitrifying bacteria which performs natural nitrate reduction.  However, testing error might be another explanation (although there is a pretty big difference between 5 ppm and 40 ppm nitrate on an API test kit).  It's possibly a bit of both.

 

If nitrate never actually reached more than 5 ppm, I suspect you should continue to dose ammonia up to 2 ppm, let it fall below 1 ppm, and repeat (as outlined in the link that Clown79 provided).

 

I'm always a little leery of using ammonia, designed for use as a household cleaner, in a reef tank.  You don't want it to contain any contaminants, scents, stabilizers, surfactants, soap, or other undisclosed ingredients.  However, I believe other reefers have also used ACE ammonia for this purpose, so it's likely OK.

[Clown79]

Is it liverock you used or dry rock (sometimes ppl call dry rock liverock)

 

If liverock(rock was in water) I wouldn't dose ammonia at all. Just test ammonia and nitrate.

 

If dry rock then the ammonia dosing procedure is required.

[seabass]

2 hours ago, Clown79 said:

If liverock(rock was in water) I wouldn't dose ammonia at all. Just test ammonia and nitrate.

I agree.  Dosing ammonia could harm or kill non-bacterial life on real ocean live rock.  Plus, it should already have enough nitrifying bacteria to support a small bio-load.  However, if it started off as dry rock, then follow the fishless cycling guide that Clown79 linked.

[Clown79]

44 minutes ago, seabass said:

I agree.  Dosing ammonia could harm or kill non-bacterial life on real ocean live rock.  Plus, it should already have enough nitrifying bacteria to support a small bio-load.  However, if it started off as dry rock, then follow the fishless cycling guide that Clown79 linked.

I'm not sure how it started but for some reason ppl are advising dosing ammonia with liverock to see if it will process ammonia in 24hrs.

 

It's not something I would think would be advisable.

[FLARGUE]

Thanks for all the advice guys. I setup the tank with live rock (wet, coming from a live rock tank at the LFS) and live sand from a bag. About a week later I received my test kit, but I noticed that there were no nitrates, nitrities, or ammonia. I figured the bacteria was there, but maybe not a significant enough source of ammonia, so dosed with ammonia to bring it to about 3PPM.

Do you think i'm ready for a couple hermit crabs and snails? I already have a small starfish and snail that hitchhiked in.

[seabass]

47 minutes ago, FLARGUE said:

Do you think i'm ready for a couple hermit crabs and snails? I already have a small starfish and snail that hitchhiked in.

Yes, but don't add any more ammonia.  You won't see a lot of nitrate unless there is a significant source of ammonia.  Plus, the live rock itself (or more specifically, denitrifying bacteria) might be processing some of the nitrate.

 

After another week, you might even add a small fish.