Preparing a tank for Parosphromenus?

[Jennifer Kronenberg]

What are your methods for preparing a tank for Parosphromenus?

Here in the US on various forums there are all kinds of “fishless cycle” methods to promote the growth of the nitrifying bacteria before adding fish to avoid the ammonia and later nitrite spikes.

I have found though that as soon as the pH is below 6 as it should be for these fish, this nitrogen cycle no longer seems to complete. I get only ammonia readings, which is probably ammonium, and never nitrites or nitrates.

Is that generally what I should expect or is there some point where there is eventually the bacteria that converts ammonia to nitrites and so on? I’m tempted to say that it is just never really a concern in a tank which is below 6 ph because the ammonia is not in a harmful form, but I would love to hear others solutions to this.

I have a tank now that I added ammonia to which has been sitting for 6 weeks now with the same ammonia readings, no nitrites or nitrates; but of course the pH is below 6.

This is a fairly concerning issue for some keepers here in the US who believe the tank should be fully prepared with all necessary bacteria before keeping the fish.

[helene schoubye]

This is probably a very controversial subject 😉
I am an admin on another aquaforum, and I can say for normal tanks, and for beginners I would always follow the ‘ordinary’ advice with regards to maturing tanks etc.
But when it comes to my own practice (with 10 years of experience) and mainly having small tanks under 25 liters with parosphromenus species, – its a different thing. I do not follow ‘normal’ procedure anymore. Not even the slightest :blush:
I use pure RO water, I dont mature the water,(but I do lower it to ph 4.5) I dont use filters. I usually prepare a tank just by filling it with water, adding substrate maybe, or if not adding lots of leaves or peat. Then putting in a few plants (javamoss mainly) and possibly an almond leave. Then I add fish.
Because I have quite a lot of tanks, and quite a lot of offspring, I need to move fish quite often, – I think its through this that I have found my own way where its actually just working. If I need to move some off spring I set up a new tank as described above and simply move them the same day. I might use some of the water from the old tank, but not at all always.

Of course I dont recomend this procedure to someone who has not got a lot of experience, because I think what is important is that there’s probably always the case in which I would not do so … I think that without thinking about it I do take note on how things are doing. If I have fry in a tank that has not been cleaned for a long time, I do take more care that I dont move them to a tank with water that is very much different. I think my main concern is really that the water that you move the fish to is close to what they come from. Too big a change is not good. That relates to ph and the amount of ‘waste’ that might have been gathering.
But I never measure amonia f.inst.
I wish I could say that I then of course is very careful about changing lots of water … but :blush: I cant even say that. I change or fill up regularly but not overly much. And of course without filters waterchanges regularly is important – in particular if you have more fish than the normal ‘one pair’.

Maybe it is because of the low ph that this procedure is possible, – I dont know about that really.
But I have also set up tanks for bettaes such as albimarginata, betta mahachai with water at 7 and I have done it the same way, no preparation really.

[Jennifer Kronenberg]

Thank you for sharing! There is a test kit sold that measures ammonia and ammonium separately so you can see whether a tank has the more harmful kind or the less harmful kind. I may just have to pick one of those up to help me decide better what to do.

As it stands, because the tanks never seem to fully cycle for me below ph 6, I have been doing the large regular water changes approach. Usually I change 150-200% of the water every week which seems like a lot when it is all being prepped several days in advance in 5 gallon buckets. I usually have 8 of these 5 gallon buckets with water in it at various stages of soaking with peat.

Now, at 6.4 pH, the tanks do cycle which is what the Betta imbellis are at now.

I do agree that it is quite the controversial topic. But, I think we can probably share differing opinions on here without it causing too much issue. Obviously your fish are doing well, spawning, young are hatching and then growing up; certainly wouldn’t be the case if what you were doing wasn’t right for your fish. I hope more on here will share their methods or even what their test results are in their low ph tanks. I don’t think you can compare them to regular tanks and apply the same method, but I may be wrong.

[Andy Love]

This is an area of particular interest to me. Perhaps I may be able to share some bits of info that, while they may not answer every question, may at least provide food for thought. I should add that I am an intrigued hobbyist ; I am by no means a trained scientist!

All my tanks are filled with soft/acidic water. I had become casually interested in nitrification, reading as much as I could in the fishkeeping context and a little wider. The received wisdom was that agents for nitrification in fishtanks are bacteria – such as the oft-quoted nitrosomonas/nitrobacter team. This belief stemmed from studies of nitrification in an industrial context (sewerage treatment etc.) and spawned various preparations that appeared on fish shop shelves … and didn’t work very well.

More progress was made by Tim Hovanec, who proposed that different genera of bacteria were responsible for nitrification in fishtanks. A new generation of ‘Bacteria-in-Bottles’ (BiB’) appeared in shops based on his research while he was employed at MarineLabs. They were more successful ; Tetra Safestart and its Americam equivalent, for example, are ones which are frequently mentioned in forums as having at least a chance of working, given the correct handling. (Tim Hovanec later left MarineLabs and began Dr. Tim’s Aquatics, which now markets its own BiB’s).

‘Bactinettes’ was another bacteria-based initiative which failed because shops couldn’t maintain the conditions necessary to keep the live cultures viable (even though the company provided refrigerators for the purpose!).

However, my experience of looking as closely as I could at nitrification in my own tanks seemed curiously different in detail from how it should have been if bacteria were indeed at work. I remained puzzled until …

… in October 2011 as I was surfing the web using relevant keywords. I came across a very recently-published account⁽¹⁾ from a Canadian group who had been evaluating various environments in which they might be able to study archea. One of the types environments that they looked at, knowing that ammonia would be generated in them, was hobbyist fishtanks. Analysing RNA, they found that the main (sometimes the only) nitrification agents present were Ammonia Oxidising Archaea rather than Ammonia Oxidising Bacteria – even when BiB’s had been used to begin a tank’s cycle. My experience began to make a little sense at last!

There have since been further papers produced by the same lab that suggest : the more acidic the environment and/or the lower the concentration of nutrient (i.e. ammonia) the less likely it seems that bacteria will be the main oxidisers.

If we rely on the hobby’s still-current wisdom, then indeed : nitrification should stop completely given certain conditions. Amongst these conditions would be, for example: a pH of <6 ; or an absence of carbonate. However during the past couple of months I have been running a bucket containing an air-driven sponge filter which has been oxidising to completion c1mg/l ammonia at pH5 and at a KH that doesn't register on my Salifert test kit (the lowest it measures is 0.3mg/l). Admittedly it takes nearly 36 hours to process each dose (it's operating at room temperature) but I think you'll agree that this rather flies against the hobby's belief in nitrifying bacteria!

A further point that seems relevant to this thread (though I'm absolutely sure that some/most/all of us must be aware of it already!) is the equilibrium between unionised (or 'free') ammonia (NH₃) and ionised ammonia (NH₄⁺). To explain, just in case you’re not confident about this …

When ammonia is bubbled into water it dissolves very eagerly. As it does so, a proportion of it becomes aqueous NH₃ and a further proportion of it becomes aqueous NH₄⁺. The relative amounts that are formed depend upon certain properties of the water : temperature ; pH ; and salinity. The two more influential properties are temperature and pH : the lower either or both of these values, the greater will be the proportion of the relatively harmless ionised ammonia present.

Most of the test kits that are available to us report on the concentration of Total Ammonia present – that is: the sum of both ionised and unionised ammonia. The kit (I think) that you’re referring to, Jennifer, that measures each separately, is Seachem’s Multitest. Interesting as it would be for you to have one, it may not be necessary to lighten your purse in order to find out how much of the toxic unionised ammonia you have in your tank(s)! The relative concentrations can be derived from a calculator⁽²⁾ provided that (as is likely) you are able to make reasonably accurate determinations of temperature, pH and conductivity.

Let’s imagine an unlikely scenario where you’re panicking because your salicylate ammonia test kit (you can’t use a Nessler kit in a typical Paros tank, of course!) reports Total Ammonia at 0.25mg/l. We’ll assume your tank is at vaguely-typical values : temp 26C ; pH5.2 ; conductivity 60uS/cm. The calculator declares that the toxic ammonia in it must be 2.33E-05mg/l. Now, I have no idea what that means (I’m pretty much innumerate!) but I know it’s a very small number. I have to crank up the Total Ammonia concentration to 1.5mg/l before I see a number that I recognise : 0.00014mg/l of toxic ammonia, which is still insignificant for practical purposes.

Total Ammonia generation in a Paros tank will be extremely low, if only because of the light stocking and the comparative low activity of the fish. There will be some nitrification being done by archaea (it should be a little faster in a tank than in my bucket because of the elevated temperature) and some ammoniacs will be used by plants (if they’re there). So, in theory, water-changes shouldn’t be required as frequently as they are in (say) a community tank filled with tapwater. Water-changes still need to be done of course (in my opinion) in order to maintain the redox balance in the tank.

I hope at least some of the above has been of interest and/or value!

{Incidentally, for the first time I noticed one of my males ‘displaying’ briefly a couple of days ago ; it was jaw-droppingly beautiful. I hope I’ll be able to get a decent photograph one day …}

1. Aquarium Nitrification Revisited
2. Fish Hatchery Management (Table 9)

[Peter Finke]

Vale, you have written a very informative posting stressing the fact that we really don’t know much about the processes within blackwater aquaria.

Nearly all we know about the bacteria life in our tanks refers to the normal aquarium with much higher pH and conductivity. And there is much of “wrong knowledge” as the stability of water values in aquaria is concerned, f.i. that a tank with no calcium will not remain stable as pH is concerned. This is simply false since the humine substances in a blackwater aquarium will act in similar a way than the missing calcium does in a normal tank. I mention this only as an example of the lack of knowledge in normal aquarium literature, that is entirely written to match the needs of normal aquarists with their normal fish from normal waters.

As you rightly point out the question of the role of bacteria is similarly bad understood as tanks with soft water and low pH are concerned; under these circumstances nitrification underlies different criteria than normally.

So, your information on the work of Tim Hovanec is very valuable indeed, and still more is that hint on those Canadian findings about the differences between Ammonia Oxidising Archaea compared to Ammonia Oxidising Bacteria. So there is a central statement of yours to be found in the words: “The more acidic the environment and/or the lower the concentration of nutrient (i.e. ammonia) the less likely it seems that bacteria will be the main oxidisers.”

I shall not go further into the interesting details you report of your own experiments; there is – of course – a difference between our European industrial products and those of the U.S., but I don’t think that “we” are much more efficient in controlling the nitrification of blackwater aquaria than you in the states. It’s only a fact that we establish such tanks quite successfully with rather a satisfying stability. But how things work and why things work and which components are responsible for it: this we all don’t know in sufficient detail.

Blackwater aquaria are possible and could be stable and beautiful, but they are only poorly understood at present. Your posting is one of the few contributions to the effort of pushing the frontiers a bit wider; thanks.

[Author]

Posts