A.trifasciata PH change effect on breeding?

[VannZannApistoFan]

I have 1 male and 2 females in a 4ft 200L planted tank and they settled in great at first, the male on occasion would chase the females around short distances for the first week. During the 2nd week both females showed breeding behaviour, they found their preferred shelters and stuck to them tail slapping and chasing the male and other female away with confidence as well as gaining their yellowish colour change. Yesterday they both abandoned their hides and are being aggressively chased all over the tank by the male. I have found the problem (I hope) after checking my water my PH was up to 7.5. This was caused by an irregularity in our local tap water I used in a water change. I've since dosed with PH Down and I'm back to 6.4.

My questions are
1 Am I right in attributing the change in PH to the change in their behaviour?
2 Will this effect how long it will take to see breeding behaviour again?
3 Am I best to remove the male until they do? The females can escape and hide but he is constantly chasing them with little rest.

Thanks in advance for any and all responses.
Vann

 

[dw1305]

Hi all,
No it almost certainly hasn't got anything to do with pH.

I can't recommend adding "pH down", if you have a look through the forum you will find there are quite a lot of posts about pH, mainly because it is a much more complex measurement than many aquarists assume. Have a look at <"Dwarf Cichlid Aquarium care"> & <"Maximum pH...">.

The females have lost their fry, possibly because you didn't have any live food to feed them? <"Raising Fry">

Apistogramma trifasciata is a harem breeder, and because the females aren't ready to spawn again, the male will chase them out of his territory and wait for some new receptive females to arrive. He doesn't know that there aren't any more females.

I found that, even though it isn't very big, the male Apistogramma trifasciata was one of the more aggressive males, and even as sub-adults I had to separate the males, and add a lot of females for each male. If you can get more females that would help, but it sounds like you just need a lot more structure at the bottom of the tank to break up line of sight etc.

In a 200l tank there should be plenty of places for the females to hide.

cheers Darrel

 

[gerald]

Yes removing the male or separating him from the females with a tank divider for a couple weeks until they have recovered and are getting yellow again would probably be the safe thing to do.

If your water has very low conductivity, then pH can rise and fall dramatically on a day-to-day basis with very little "real" change in water chemistry. Big pH swings in water with very low conductivity are usually not biologically significant to the fish, since the actual changes in ion concentrations (causing the pH swing) are really very small. (Did I explain that right Darrel?)

Trifasciata is not one of the "obligate blackwater" species that really needs low pH. Mid-7's should be okay for that species, although breeding success might be a little better in the 6's.

 

[dw1305]

Hi all,

If your water has very low conductivity, then pH can rise and fall dramatically on a day-to-day basis with very little "real" change in water chemistry. Big pH swings in water with very low conductivity are usually not biologically significant to the fish, since the actual changes in ion concentrations (causing the pH swing) are really very small.

I think that would be where I'm coming from. In soft vegetated water, like you might find in the Pantanal, big diurnal pH swings must occur as the relative concentration of oxygen and CO2 change.

Even in buffered systems, if you look at aquascapers who add CO2, they are causing rapid pH drops (and rises) by altering the CO2 (H2CO3):HCO3 equilibrium, without any apparent problems for their fish.

In more natural situations high levels of CO2 will normally be correlated with sub-optimal levels of dissolved oxygen, so it is more difficult to separate the effects of low DO levels from those of low pH.

cheers Darrel