Need advise on cycling tank

[honfui]

I need advise on whether should i turn off my protein skimmer.

My tank have an serious ammonia spike last week (90% livestock in the LRs died), so ppl advise me to turn on the protein skimmer to remove the extra protein and to save my LRs.

Now my tank is "back to normal" and the ammonia is in control (low). My tank now is at the NO2 spike level so i just wondering should i turn off my protein skimmer now since the ammonia spike is over and most ppl did not turn off their protien skimmer during the cycle.

Lastly, any idea how long will the NO2 process last? My ammonia drop within 1 week. So is the NO2 will drop within 1 week as well.

Btw, my tank is 2ft with around 10KG LRs now.

[Achilles Tang]

Well.... if your water is clean, your LR is well-cured and your tank too sterile, then turning on a good skimmer may actually prolong the cycling process as it will skim out dissolved organics before they have a chance to break down into an ammonia source to start the cycle.

That is why it may be necessary to 'spike' a tank with a source of ammonia (decomposing dead prawn recommended) to kickstart the cycle.

Using uncured LR should produce enough ammonia to kick start a cycle. You can hasten it further with the usage of a dead prawn. However, too much ammonia produced could end up killing all the inhabitants of LR (eg. inverts like worms and crabs).

You can turn on the skimmer to help improve oxygenation or to help clean up the water (if you don't want to do a water change) should a crash occur.

But now that your tank is so-called back to normal... you should first ensure that ammonia is truly zero, not just 'low'. NO2 spike should last about a week and a half, give or take a few days. Same for NO3, although the gradual drop to zero is really dependant on the filtration setup you did for your tank.

Some tanks will perpetually have a consistently high reading of NO3 because they use canisters, bioballs, wet/dry systems etc, lack of ample LR, no or poorly setup sandbed for the simple reason that these fail to provide a anaerobic environment for the right kind of bacteria (that process nitrates to nitrogen gas).

There is really no exact time frame to tell you... every system is different. You should only rely on testing regularly daily/every two or three days in the cycling period (average a month) with good reliable test kits until you are sure every part of the cycle is truly complete.

Then SLOWLY stock up or you'll waste time rectifying another mini-cycle.

[jc85]

Hi AT, will the N03 drops after cycling? Heard that DSB/plenum will take at least 6 months to mature. Is water changing the only way to remove N03?

[Kalib]

A sump with macroalgae refugium is another way to help control NO3.

[Achilles Tang]

NO3 should be very low or could even be undetectable after cycling.

But once you start stock up on fish and starting feeding your tank... the byproducts of respiration and body wastes will generate minute amounts of ammonia, which is processed efficiently by aerobic bacteria.

Thus, harmful ammonia and NO2 is not present in enough quantities to affect your livestock.

However, in improperly setup tanks (either through ignorance or space restrictions), there is insufficient anaerobic areas for the anaerobic bacteria to convert nitrates into nitrogen gas.

If you can't setup a DSB to deal naturally with nitrates... then you can try packing your tank with lots of LR of the right type (dense and large pieces where the centre is anaerobic).

You deal with it chemically eg. AZ-NO3, other nitrate absorbants or by mechanical methods, water changes, denitrators etc.

[Rufff]

If you can't setup a DSB to deal naturally with nitrates... then you can try packing your tank with lots of LR of the right type (dense and large pieces where the centre is anaerobic).

Centre is anerobic? U mean if DSB cannot be employed, the LR takes the place of the DSB, thus housing the anerobic bacteria? If have both even better??

Sorry if question sounds silly ...

[bwilly]

Centre is anerobic? U mean if DSB cannot be employed, the LR takes the place of the DSB, thus housing the anerobic bacteria? If have both even better??

Sorry if question sounds silly ...

yes..

as mentioned. NO3 to nitrogen conversion need bacteria that thrive in veri low oxygen area.

Ammonia n NO3 bacteria different environment. Oxygen rich place to thrive.

[Rufff]

OK thanx bwilly.

[Achilles Tang]

Centre is anerobic? U mean if DSB cannot be employed, the LR takes the place of the DSB, thus housing the anerobic bacteria? If have both even better??

Sorry if question sounds silly ...

Yes... it's called the Berlin method.

Using lots of LR to provide the core of natural biological filtration. A Modified Berlin Method is the use of a skimmer with it. No sandbed, just a glass bottom. Detritus should be siphoned out.

Some reefers still use this method...