Tank cycling methods test

[Vsevolod Stakhov]

Hello, I have recently conducted a simple hobbyst experiment to test different methods of 'quick' tank cycling using the following approaches:

• Add bacterias from a bottle:
  • Seachem Stability
  • Tetra Easy Start
• Add some gunk from the existing filter:
  • From prefilter sponge
  • From biomedia sponge
• Add some soil from garden
• Add filter media from the existing filter:
  • HelX plastic media
  • Seachem matrix media

So the experiment was organised in the following way: I have taken four 1L bottles, filled them with tap water (v. hard with phosphates), added 1 drop of sodium tiosulphate sollution to remove chlorine and subsequently added NH4Cl sollution to increase ammonia level to 2ppm. I have set these bottles with an airstone and quite a strong air pump for 24h aeration:

Then I have tested the water using API NH4 (saliciate) test, ensuring that the initial NH4 levels were the same.
So the first test was for the following four candidates:

• Control (nothing added)
• Garden soil (2 pea size pieces)
• Filter gunk from the prefilter
• 1ml of Seachem Stability

Initial results (same order as above):

Nitrification has started visually from the day 3:

After 7 days I had the following picture (control, soil + nitrite, gunk, stability):

I have added nitrite tests for two leaders: garden soil and Seachem Stability. It seems that garden soil was the winner on ammonia -> nitrite stage but failed badly on nitrite -> nitrate stage. Seachem Stability removed almost all ammonia and almost all nitrite. That was quite surprising.
Subsequently, I have tested 4 other approaches:

• Seachem Matrix element from a working filter
• Tetra SafeStart (5ml in 1L bottle)
• Filter gunk from HelX biomedia washed out by tank water
• HelX element from a working static media filter:

Same 2ppm ammonia on day 0 (same order as above):

Nitrification has started roughly at the same time - on day 3 (a poor photo, sorry):

After 7 days results were the following (matrix, tetra + nitrite, gunk, helx):

So HelX has won this stage but probably because it was able to float in the aeration bubbles unlike, for example, Matrix. Tetra Safe Start was not so impressive as well as filter gunk (I have also measured nitrites for it as you see, and their level was almost zero). HelX element was able to oxidise both the vast majority of ammonia and almost all nitrite - similar to Seachem Stability in the previous experiment.
In conclusion, it seems that bacteria matrix is more important than the bacterias themselves. So undestructed biofilm acts much faster and better than everything else (especially untreated sample). I'm not quite sure what happened with the garden soil sample with regard to nitrites. I can only suspect that there was something wrong with the nitrtite oxydising bacterias when they were moved to the submerged conditions (or those bacteria live somewhere deeper in the soil).

This experiment was done mostly for fun but I think it might be somehow useful for others.

 

[dw1305]

Hi all,

This experiment was done mostly for fun but I think it might be somehow useful for others.

I think it definitely is of interest.

..... In conclusion, it seems that bacteria matrix is more important than the bacterias themselves. So undestructed biofilm acts much faster and better than everything else (especially untreated sample).

I think you are right, you can get "free living" nitrifying organisms, but they usually found where you have enough time and nutrients for <"microbial "flocs" to form">. This is one of the reasons that a planted tank, with a substrate, enhances nitrification. <"Radial Oxygen Loss">, from the roots in the rhizosphere <"greatly increases the area for nitrification">.

..... I'm not quite sure what happened with the garden soil sample with regard to nitrites. I can only suspect that there was something wrong with the nitrtite oxydising bacterias when they were moved to the submerged conditions

Could be. It might also be to do with the initial ammonia level. <"COMAMMOX Nitrospira"> look to be both important players in nitrification and inhibited by high ammonia levels. I don't know how this applies to canonical non-COMAMMOX Nitrospira (that just oxidise NO2- to NO3-), but you may be interested in <"Dr Tim Hovenec's comments">.

So HelX has won this stage but probably because it was able to float in the aeration bubbles

I'm generally a fan of <"floating cell media">, even in (relatively) <"static situations">.

cheers Darrel

 

[Vsevolod Stakhov]

Could be. It might also be to do with the initial ammonia level. <"COMAMMOX Nitrospira"> look to be both important players in nitrification and inhibited by high ammonia levels. I don't know how this applies to canonical non-COMAMMOX Nitrospira (that just oxidise NO2- to NO3-), but you may be interested in <"Dr Tim Hovenec's comments">.

That's quite interesting! But the question I have here is if anammox is ever possible in aerobic conditions? Apparently, the top soil level is totally aerobic. Also both Seachem Stability and filter media from the running filter were somehow able to deal with NO2 levels counting that ammonia level.

Seachem Stability performance was also very surprising to me, as that bottle had no filter media, no substrate, nothing. And it was neither chemical oxidation (as nitrite levels were not zero) nor ammonia test inhibition (like Seachem Prime or just Sodium Tiosulphate does), since it definitely started from high levels of ammonia and dropped down quite quickly in a few subsequent days.

I'm generally a fan of <"floating cell media">, even in (relatively) <"static situations">.

Same here. I've now replaced all my ceramics with K1/HelX and I'm very happy about it. I've also measured ammonia oxidation speed in the working tank with two types of media (by adding extra NH4Cl) and it seems that plastics oxidies that ammonia even faster than ceramics. Also it never clogs.
In fact, I plan to use those 4 bottles to test various filter media for nitrification purposes: ceramics, sponge, matala mat and plastic rings. However, I'm currently out of extra k1/HelX, so I'm waiting for it to be deliviered.

 

[dw1305]

Hi all,

I have here is if anammox is ever possible in aerobic conditions?

........ I should also have said that in the ANAMMOX process you don't have full nitrification - NH3(4+) → NO2 → NO3, and the final electron acceptor is nitrite (NO2-). You still need three molecules of oxygen (O2) for every two molecules of ammonium during the initial aerobic partial nitrification........

Entirely aerobic, <"not ANAMMOX">, but <"COMAMMOX">, the recently discovered ability of some Nitrospira bacteria to oxidise ammonia (NH3) directly to nitrate (NO3).

Seachem Stability performance was also very surprising to me, as that bottle had no filter media, no substrate, nothing. And it was neither chemical oxidation (as nitrite levels were not zero) nor ammonia test inhibition (like Seachem Prime or just Sodium Tiosulphate does), since it definitely started from high levels of ammonia and dropped down quite quickly in a few subsequent days.

Seachem won't tell you what is in any of their products, so it is largely guesswork. If you had a product that contained <"Ammonia Oxidising Archaea"> (AOA) that might account for it. I'd refer back to Dr Hovenec's comments (in the thread linked earlier) for a more complete discussion.

I've also measured ammonia oxidation speed in the working tank with two types of media (by adding extra NH4Cl) and it seems that plastics oxidies that ammonia even faster than ceramics. Also it never clogs

The non-clogging aspect was the bit I really liked. I'm not that interested in TAN in the tank, that isn't because it isn't important, but I'm pretty confident that <"I have mechanisms"> that mean high ammonia levels are never a problem. I recently became aware that some people keep fish at stocking levels that require a <"slightly different approach">.

I just like systems with plenty of plants, entirely aerobic filter media, a relatively undisturbed substrate and high levels of dissolved oxygen, this means that the tank always has the capacity to deal with an unexpected increase in <"Biochemical Oxygen Demand">.

cheers Darrel

 

[Vsevolod Stakhov]

Entirely aerobic, <"not ANAMMOX">, but <"COMAMMOX">, the recently discovered ability of some Nitrospira bacteria to oxidise ammonia (NH3) directly to nitrate (NO3).

I was not aware of this process, thank you for mentioning it!

Seachem won't tell you what is in any of their products, so it is largely guesswork. If you had a product that contained <"Ammonia Oxidising Archaea"> (AOA) that might account for it. I'd refer back to Dr Hovenec's comments (in the thread linked earlier) for a more complete discussion.

As far as I understand, AOA have quite a low reproduction speed, but I might be wrong here...

I recently became aware that some people keep fish at stocking levels that require a <"slightly different approach">.

Yes, that's look similar to my malawi tank. In 3 years it progressed from this one:

to this one:

Mostly because they breed like crazy