In praise of plants (again)

[seangee]

Around 6 weeks ago I went off on 3 weeks hols. The day I got back I did my usual water changes - water change only never touched the plants.
Sad to say I have done nothing since besides feeding. First I came down with the lurgy and then just as I was getting over it I got a nasty eye infection.

Happily I'm all over it now so decided to attack the tanks today. These were all completely overgrown with frogbit and between them I scooped out over 20 litres of the stuff. Understandably they were very dark. When I got to the community tank I noticed a lot of surface scum / muck. Oh no - I forgot to turn the filter back on, and its probably been off for 3 weeks! What I saw was left over food trapped in the floating plants
Pic is after scooping out a full bucket of frogbit and pulling the tops off the ambulia, but before changing the water or cleaning the glass. I also never trimmed anything else. The advantage of low tech is as the light goes the plants below grow slower but suffer no real ill effects. The fish are all acounted for and appear to be thriving.

Before the next time you get in a panic that your filter has failed remember that insurance is cheap and easy . And NO! I'm not in the least bit worried that I have lost my cycle.

 

[AJ356]

In terms of plants being a good insurance if the filter stops working. I'd argue they are of course, but It depends sometimes at night, because in a very heavily planted tank without surface agitation in the dark, the oxygen levels can deplete a lot as the plants I believe consume O2 and discharge CO2?

How heavily the tank is stocked with fish is obviously a key factor.

You won't lose the cycle because in a heavily planted tank like yours the beneficial bacteria are probably on gardening leave anyway and have little work to do.

 

[seangee]

I have said for a long time the filter only exists to move water around and provide mechanical filtration. Well it does have work to do now
There is a small could on the horizon though. This tank has been free of duckweed for 8 months. The last few weeks have created the perfect contitions for that one dead sliver that I had overlooked to kick back into life. No way it has been introduced.
Oh well - here we go again.

 

[TwoTankAmin]

There would be little reason for losing the cycle. No matter how many plants one has there will also be some amount of bacteria present. The only thing the filter failure might cause that could harm the bacteria is a lack of surface afitation might deplete the oxygen. The fish are making ammonia and so is any decaying organic matter. The fish are also making CO2. So those things the bacyeria need are there,

However, the frogbit is likely getting most of the CO2 it needs from the air as they are on the surface. If the fish are breaking the surface at all, some gas exchange is also happening if they are moving the frogbit around some which would also allow for some gas exchange.

So, I am not all that surprised that the tank and fish did OK for those weeks.

 

[f_luxus]

The only thing the filter failure might cause that could harm the bacteria is a lack of surface afitation might deplete the oxygen.

It's not even the bacteria that die. Nitrifying bacteria are capable of switching to nitrite respiration. What dies, however, and thus causes massive problems, are all the microorganisms like rotifers, tardigrades, and even ostracods and nematodes in the filter material.
For example, I only use filter wool, which I throw away completely every few weeks.
I still can't detect any nitrite in the water.
The bacteria are found in large numbers on the surfaces in the aquarium, such as rocks, wood, panes, and the substrate.
I mostly run my Betta tanks without filtration, but with plenty of Hemianthus callitrichoides and moss. The only exception is the breeding tank (for fry starting at about 1.5 cm), which is fed quite frequently.
I need circulation there, otherwise I run into problems with cyanobacteria.

 

[TwoTankAmin]

Um- the nitrite in our FW tanks is created by the bacteria from ammonia ozidation. If there is no ammonia present there will not be any nitrite either.

But, the ammonia oxidizers in fw aquariums cannot switch to nitrite respiration. Without getting overly technical on this thread. it boils down to this. Bacteria like Nitrosmonas europa can switxh to nitrite respiration but these are not the ones found in our tanks. This abstract from Doctor Hovanec's paper summarized this was the case.

Burrell PC, Phalen CM, Hovanec TA.2001.Identification of Bacteria Responsible for Ammonia Oxidation in Freshwater Aquaria. Appl Environ Microbiol67:.https/doi.org/10.1128/AEM.67.12.5791-5800.2001

ABSTRACT​

Culture enrichments and culture-independent molecular methods were employed to identify and confirm the presence of novel ammonia-oxidizing bacteria (AOB) in nitrifying freshwater aquaria. Reactors were seeded with biomass from freshwater nitrifying systems and enriched for AOB under various conditions of ammonia concentration. Surveys of cloned rRNA genes from the enrichments revealed four major strains of AOB which were phylogenetically related to theNitrosomonas marina cluster, theNitrosospira cluster, or the Nitrosomonas europaea-Nitrosococcus mobilis cluster of the β subdivision of the class Proteobacteria. Ammonia concentration in the reactors determined which AOB strain dominated in an enrichment. Oligonucleotide probes and PCR primer sets specific for the four AOB strains were developed and used to confirm the presence of the AOB strains in the enrichments. Enrichments of the AOB strains were added to newly established aquaria to determine their ability to accelerate the establishment of ammonia oxidation. Enrichments containing the Nitrosomonas marina-like AOB strain were most efficient at accelerating ammonia oxidation in newly established aquaria. Furthermore, if the Nitrosomonas marina-like AOB strain was present in the original enrichment, even one with other AOB, only the Nitrosomonas marina-like AOB strain was present in aquaria after nitrification was established. Nitrosomonas marina-like AOB were 2% or less of the cells detected by fluorescence in situ hybridization analysis in aquaria in which nitrification was well established.

As far as I can tell what you describe in terms of rhe autotropjic ammonia oxidizers switching to nitrite respiration, while it is possible in other environments, im FW aquariums it does not occur. But. I am not a microbiologist so I could be wrong on this.

What I also found is if you ask the Google AI. "are the autotrophic nitrifying bacteria capable of switching to nitrite respiration pn freshwater aquariums?" The answer is

In general, the traditional autotrophic nitrifying bacteria found in freshwater aquariums cannot switch to nitrite respiration. These specialized bacteria are obligate aerobes, meaning they require oxygen to perform their nitrifying functions.

from https://www.google.com/search?sca_e...hUKEwjOqr-p2bGQAxWsD1kFHQL1KOMQvgUoAXoECBEQAg

 

[GaryE]

As I grow older and begin to resemble a stem plant with bad lighting, I've learned some stuff @seangee 's tank confirms. Yes, the plants are important, but so is the very light and sensible stocking.

A lot of us, especially new aquarists, start out by making a huge mistake on day one. We seek out a formula or a site that gives us the maximum possible stocking level. And then we stock to it.

I've become convinced that you go to a stocking site, see how many fish your tank's capacity is, and never surpass 50% of that unless the fish breed. Maybe 75% is okay, but overstocking is a fatal error.

Overstocking makes us dependent on the tech we buy. I love my HOBs and want the water in my tanks to move, because I like fish that come from streams. The filtration media in a large enough HOB can keep my tank alive. Yesterday, I moved a pair of Apistogramma agassizii to a 30 inch 25 gallon that is completely 'raw' -set up the day before with new gravel. There are established plants, and rocks from other tanks, but for a few weeks, the filter, which I ran on another tank for 3 weeks to bring it to life, is going to be essential.

@seangee's understated and beautiful planted tank doesn't look like a subway transfer station at 5PM (sorry @seangee , but you just haven't pulled off that popular look...). So it can survive a filter breakdown or an unplugging (why I never do that). That's a fine set up.

Generally, if you want more fish you have to face the possibly expensive fact you need more tanks. If you stock properly and plant, you get a resilient habitat.

 

[f_luxus]

What dies, however, and thus causes massive problems, are all the microorganisms like rotifers, tardigrades, and even ostracods and nematodes in the filter material.

I just wanna say, that's the bigger problem