water changes

Although it is over 10 months old – it remains an interesting question.
I wonder why nobody else contributed to this thread.

I found it looking for informations about the intervals of water changes that paro breeders normally keep.

I have several tanks using no technical equipment, just some additional lighting in the winter months. No heating, no filter. My fishes are Badis species, Dario and Pseudosphromenus. Every week I change about 20% of the water in these tanks, and they run quite well.

Now, having my first paros, I found a number of forum posts or articles which say that paros do not like too frequent water changes. On the other hand – paros like very clean water with low conductivity.

How often do the experienced paro breeders here make water changes?

So you just refill the evaporated water? And never make water changes?

Here in Germany I know of a community of aquarists who never change the water in their tanks. There is an “Altwasser” (=old, unchanged water, I don’t know an English term for it) forum as well ….. very interesting.
The aquarium as a miniature eco system, with as little intervention as possible.
An appealing thought for somebody like me – already using only rain water and natural components – and no technics.

What do the others think, and how is your water changing frequence?

To the most experienced breeders of Parosphromenus things are quite clear: Water change as often as possible and as much as possible. These fish live in streaming or flowing waters. Nearly never (with a few exceptions only, that could be explained easily by a change in the landscape) they are to be found in still waters.
That means – and I agree with this by considering my own mentality – that doing seldom a water change is only a matter of laziness. I have 33 small 10-liter-tanks without any technique besides light. I am able to breed all species there and I do very little water change. I mainly use Ceratopteris as a plant of a certain hygienic value (the other plants, Java moss, other moss species, Java fern, rarely a crypt) could be forgot in that respect; they are merely decorative. (But even a filter would not alter the situation completely). Good, strong licorice gouramis are doing well in this situation but they don’t breed constantly. They breed – if well fed – immediately after a big change: of water or of the whole tank. But since I do not want them to breed constantly I am satisfied. There are friends trying to do much more water change than I am able to to, say every week a third or up to a half. They sometimes have a problem with this: the fish breed nearly constantly. Therefore they don’t admit freely but it’s true nevertheless: they become lazy, too.
My laziness is helpful, partly. It prevents me from having too much fry. Since my fish stand it for long times (weeks, even months in tanks with a pair only, some young and good growing Ceratopteris, everything is fine, or seems to be fine. Several times I had about fifty or sixty young filamentosus or linkei or spec. Danau Rasau growing up for a few months in that crowded environment of ten liters! Then the possibility or probability of outbursts of infections is very high, mostly Oodinium: small at first, not to be seen at all at the fish’s body, but if you don’t change water even in this situation it will grow rapidly. In bad cases I have lost the fish. So I feel guilty: it was my mistake.
I think we should admit that changing no waters or doing that in some weeks or even months time is biologically wrong even in a 50-liter-tank with one pair only and only due to our laziness. Even tanks with moving water or with filter streaming are a compromise if you want to keep organisms from flowing waters. Perhaps, merely keeping fish will not detect this, but breeding will. Breeding is the true measure of the fish’s well-being. And with the licorice gouramis we have to decide: the more often you are doing the changes and the more water you change the more young you will have. And our adult fish are rather hardy normally. They stand long periods of deteriorating environmental conditions, but then they don’t breed.
Of course doing frequent water change (as my friends and master breeders Allan Brown, Martin Hallmann, Günter Kopic, Horst Linke or Bernd Bussler (most of them dispose of plants altogether, that is to be added; not Horst who does it the same way than I do) t r y to do: weekly up to the half) presupposes technical means for this if you have 20 or more of small tanks of 5 to 100 liters. Above all you have to prepare the water in big enough quantities with the right pH between 3.5 and 6.0 and the right Microsiemens between 10 and 80. That all is difficult. I manage to a certain extent. But keeping my 33 small tanks in exact the way I consider the best I am totally unable. So I like my fish bearing my laziness for long times.
I always hope that they stand it without much damage. And often they do: Yesterday I moved my P. parvulus, not the easiest species, after about half a year in a tank well filled with growing Ceratopteris into a newly set-up tank with 80% of fresh water, and immediately thy began displaying and show signs of breeding behaviour.
There is a clear biological explanation of this: In nature our fish are not only inhabitants of flowing waters but there are clear spawing periods, too. They are dependent from big events, mainly heavy tropical rainfall. Then, the microfauna explodes and the young have enough to feed on. You can follow the same scheme in the aquariums: The big change induces the breeding behaviour. If you get healthy, adult fish anew, they try to breed in the next days. If you put your fish in a new tank with new water: they begin with breeding preparations. And if you change a big quantity of water: the same. And if you don’t they stand it. They normally don’t die. But they become lazy themselves. As I am.
So that’s my conclusion: The licorice gouramis are quite good for lazy people. They stand a lot of our laziness. Although there are borders. If you have one or two small tanks only, it’s no problem. The even a lazy person could change water rather often. Do! Your fish will reward this by spawning. And if you don’t? It will be no big problem if your tank is filled by growing plants, but the fish will not or seldom spawn. Sometimes at the beginng, nearly never later on. Until you overcome your laziness and change a big amount of water or even fill the whole tank anew or transfer the fish to a new tank at all.
So, decide if you want to speak about an ideal or about reality, about the ideal Paro-aquarist or about your real practice. It’s important to know both: You must know the ideal in order to know what to do if you can, and you must know the reality in order to know what the fish can stand.

Since the fish have clear spawning periods in nature I don’t believe it is good to keep them spawning constantly. They will get exhausted and die young. This is one of the reasons I don’t change water often. I mostly do it when I think it is a good time for them to breed.

Fish (and especially paros!) adapt and specialize to the environment they live in. For paros this is acidic and soft water with clear spawning seasons. Because they specialize to this environment they lose the ability to thrive in other conditions in a certain way. We experience that when they are put in wrong water. I believe this also goes up for spawning seasons. Paros are adapted to spawn in certain periods. Spawning them constantly means going against nature, which can only harm the fish.
Nature always knows best, so I have a strong tendency to believe her.

I think that is a good way to keep them. So don’t change so much they breed constantly but do change little bits. That seems plausible to me.

Hi all,

I’m still fairly new to this forum although I’ve registered for quite some time.

I emailed to Peter Finke 2 days ago and this is what I wrote;

Here’s another interesting subject that I hope to hear from your opinion. There is a similar topic in the Paros-project forum which you have all discussed there. However, I would like to include a few more things that have been in my mind for a while.

> An old/seasoned tank often accumulates a lot of mulm/decaying organic material at the bottom of the tank. I leave these stuff there whenever I do water changes, only siphoning the water column to about 30 – 40% and replace it with either 80% distilled water and 20% tap water or simply 100% distilled water/RO.

> Decaying leaves left in the tank creates a teem of microorganisms but I believe the species are different from the ones which usually occur in a normal aquarium (Those that obey the principle of biological cycling process).

Hope to hear from you. Thanks!

Hi Peter,

I’m glad for your response. 🙂

From what you mentioned, I believe what I’m doing is wrong. :unsure: Usually, I leave the leaves in the aquarium till they have fully broken down. I used to remove the mulm diligently but the fish don’t like it, so nowadays, I keep some of it.

Some of my tanks also have peat and I use various aquatic plants to delay the water changes, such as Ceratopteris sp., Java ferns, moss, Pistia stratiotes and Utricularia gibba. I noticed that whenever the decaying leaves and mulm are removed from the tanks, with fresh leaves added, the water turns slightly cloudy after 2-3 days. I think the removal of the detritus not only removes the physical waste, but also the microorganisms that are already thriving in it. The fresh leaves therefore, as they decay over the first few days, creates a new population of microorganisms. I’m sure this is similar to what is happening in an otherwise, normal healthy aquarium going through the phase of cycling.

As much as I have said, I hope to hear from more opinion from as many blackwater fish specialists as possible. 🙂