Hello everybody,
first of all: really nice tank, Sverting. Both, the dimensions and the setup with the peat moss and the thin roots, look very impressive.
But I agree with Peter when it comes to breeding. I made the experience, that paros need some quietness during mating and especially while caring for the eggs and fry. If the males are stressed too much, it sometimes leads to disappearing clutches etc..
What I observed with 2 pairs of P. phoenicurus in a 45l-tank was, that the 2 females spawned alternately with one dominant male (this male occupied the whole tank, although I had structured it into 2 territories. The other one was pale and standing in the corner). During every spawn the eggs/fry of the previous spawn were completely eaten (perhaps by the female?). So I watched several spawns but no fry developing. After separating one pair I finally got the first fry.
I think the problem is, that conditions in our tanks (even the “bigger” ones e.g. 30-50l) are much more confined than in nature.
So, from my experience, I would say that the size of the tank doesn’t matter too much, but that there’s only one pair for themselves seems to be essential for the development of fry.
Of course, this doesn’t mean, that you couldn’t be successful at any rate and shouldn’t try it.
If you should experience the same as I did, you can still catch out a nice couple and give them a quiet 20l-tank with a small cave, peat, beech/oak-leaves and Ceratopteris for their own.
To the plants:
I was experimenting with different (almost all) species of crypts that are available in the aquarium trade. Most of them come from limestone areas in Sri Lanka and are therefor hardwater-species. I knew that, but still wanted to do the experiment and planted them in my show-tanks with iron-fertilizer-substrate covered with sand (some also in pots with pure sand). The result was that all of them melted within hours (pH: 5.0-5.5). So, I draw the conclusion, that they are simply not suitable.
Selection:
Do you really think you can simulate natural selection in a small 70l-tank with some Boraras? I believe, that aquarium-strains are always a little “different” from the wild type (at least after some generations). With paros, I’ve never experienced something like laziness.
If I were you, I’d pick out the best-looking couple and give them a seperate tank as Peter suggests and put the others in your beautiful community-tank. This way, you could have both: watch the mating and spawning behaviour of your couple and some territorial behaviour of the group in a nice community-setup. Apart from that you would enjoy “breeding-success”, because of course paros are way too precious to be only “kept” and on the long run wasted in a community tank.
Greetings
Martin