Blackwater breeding tank

[Apistoguy52]

Got a new 1m, 100L tank setup and almost ready for fish. pH 5.5, 100ppm tds. Time to make some blackwater Apistogramma babies!

 

[MacZ]

What species are you aiming for? Or is that not yet clear?

Can you dial down the TDS a bit more?

 

[Apistoguy52]

What species are you aiming for? Or is that not yet clear?

Can you dial down the TDS a bit more?

There is a species I’m aiming for. Have to wait another week to see if it actually is coming. Fingers crossed. Have a reasonable plan B if that doesn’t work out.

Probably can’t dial down the tds. In your experience, is a 100ppm tds problematic in terms of reproduction?

 

[Mike Wise]

Uh, where are the territorial boundaries? A dominant fish that can see across the entire tank will consider the entire tank its territory and cause problems for other fish.

 

[Apistoguy52]

Uh, where are the territorial boundaries? A dominant fish that can see across the entire tank will consider the entire tank its territory and cause problems for other fish.

I suppose that is kind of the goal in trying to replicate a sandbar with scarce cover. Few sticks, few leaves, and a few caves buried in the sand.

 

[Aquaticloch]

If that’s your goal it won’t be suitable for a pair of apistos

 

[MacZ]

I suppose that is kind of the goal in trying to replicate a sandbar with scarce cover. Few sticks, few leaves, and a few caves buried in the sand.

How do you get to this conclusion? Blackwater habitats can look wildly different. Even within a stretch of creek you have the banks, leaf litter zones, open water, open sand, maybe a pool with little current on one side... Not all fish prefer the same parts of a habitat, even if it's just 2 meters apart.

And while yes, there are some species that live in the open, replicating this in the aquarium will likely not work. In the wild females that are not ready to spawn are chased away and can simply leave, just as rival males. A tank is restricted in that regard. If you don't put in any structures the fish will be able to see each other all the time and whoever attains dominance will be able to chase and maybe outright kill any fish it doesn't want in their territory.

Probably can’t dial down the tds. In your experience, is a 100ppm tds problematic in terms of reproduction?

Considering the above that is a problem you can focus on at a later point. But yes, TDS is more important than pH. With 100mg/l TDS your tank isn't considered blackwater, even if your pH is at 5.5. Even my own tank with 40mg/l TDS and a pH of 5 is factually not blackwater. What are the TDS comprised of? Do you have still measurable GH and KH maybe? What do you use to lower pH?

 

[Apistoguy52]

Bummer….I really thought I would be able to keep sandbar Apistogramma, in a sandbar-ish biotope. Suppose I still have a good bit of time before fish may arrive, so there’s still time. A. psammophila are surprisingly tough to come by.

Macz-
I’m not terribly concerned about meeting the specific definition of blackwater, my only concern is creating water chemistry that would allow reproduction. Faux-blackwater is perfectly fine with me. Of the 100ppm tds present, I’d wager the bulk is GH, little sodium, more magnesium, and the remainder in calcium. How much softer would I need to make it to get blackwater species eggs to hatch?

Thanks!

 

[MacZ]

I’m not terribly concerned about meeting the specific definition of blackwater, my only concern is creating water chemistry that would allow reproduction. Faux-blackwater is perfectly fine with me. Of the 100ppm tds present, I’d wager the bulk is GH, little sodium, more magnesium, and the remainder in calcium. How much softer would I need to make it to get blackwater species eggs to hatch?

Yeah and that's the problem, faux blackwater won't do it. Blackwater IS defined by the water chemistry, not by the tint. (Yes, I'm a broken record, but that's simply it.)

For true blackwater species, especially if wild caught: You need to get in the 2 digit range under 50, GH 0, KH 0. The TDS should comprise basically only of humic substances and maybe some DOC. pH is comparatively irrelevant, it can be as high as 6, while 5 to 5.5 should be what you're aiming for.
You will only get there with RO, distilled, DI or rainwater.

Here you can look up the water parameters of the Rio Atabapo, where your future Apistos come from.

The values I see in the map are between pH 4 and 5 and conductivity below 10 (which means TDS were below detection).

 

[Apistoguy52]

Yeah and that's the problem, faux blackwater won't do it. Blackwater IS defined by the water chemistry, not by the tint. (Yes, I'm a broken record, but that's simply it.)

For true blackwater species, especially if wild caught: You need to get in the 2 digit range under 50, GH 0, KH 0. The TDS should comprise basically only of humic substances and maybe some DOC. pH is comparatively irrelevant, it can be as high as 6, while 5 to 5.5 should be what you're aiming for.
You will only get there with RO, distilled, DI or rainwater.

Here you can look up the water parameters of the Rio Atabapo, where your future Apistos come from.

The values I see in the map are between pH 4 and 5 and conductivity below 10 (which means TDS were below detection).

Interesting. I’ve always figured pH trumps TDS. What species of blackwater fish are you breeding? Do you notice any development issues with the fry and their fins?

 

[MacZ]

I'm not breeding at the moment. I run my biotope tank at these parameters.
But I know of no development issues if bred and raised in these conditions. I just grew out a group of Dicrossus filamentosus from fry (barely 2cm) to adult and I haven't seen any issues that would have been down to water parameters.

TDS 30-40 (Humic substances, DOC, fertilizer for the plants -> about 10mg/l each) based on 100% RO with TDS of 5. EC is accordingly at about 70µS/cm.
pH: Roughly 5, I can only use reliable instruments for pH testing every now and then, because I have to borrow them. But each time I have the opportunity I get readings of 4.8 to 5.3.
Temp: 26/27°C

I have never seen any bacterial issues of any kind in my tank since it reached these conditions either, same for fungal infections. Of the last 4 losses I had, 3 were due to old age (Pencilfish) and one by way of territorial aggression (Dicrossus).

 

[Apistoguy52]

I'm not breeding at the moment. I run my biotope tank at these parameters.
But I know of no development issues if bred and raised in these conditions. I just grew out a group of Dicrossus filamentosus from fry (barely 2cm) to adult and I haven't seen any issues that would have been down to water parameters.

TDS 30-40 (Humic substances, DOC, fertilizer for the plants -> about 10mg/l each) based on 100% RO with TDS of 5. EC is accordingly at about 70µS/cm.
pH: Roughly 5, I can only use reliable instruments for pH testing every now and then, because I have to borrow them. But each time I have the opportunity I get readings of 4.8 to 5.3.
Temp: 26/27°C

I have never seen any bacterial issues of any kind in my tank since it reached these conditions either, same for fungal infections. Of the last 4 losses I had, 3 were due to old age (Pencilfish) and one by way of territorial aggression (Dicrossus).

So you have bred/raised fry under these conditions? Which species?

Sorry for all the questions. With the internet being the internet, it’s difficult to determine if you’re getting first hand experience from someone who’s very experienced, or if your getting what someone thinks is good advice because they got a pair of cacatuoides and a Linke/Staeck Apistogramma book and they’re enthusiastic (nothing against the Linke/ Staeck book).

 

[MacZ]

So you have bred/raised fry under these conditions? Which species?

Sorry for all the questions. With the internet being the internet, it’s difficult to determine if you’re getting first hand experience from someone who’s very experienced, or if your getting what someone thinks is good advice because they got a pair of cacatuoides and a Linke/Staeck Apistogramma book and they’re enthusiastic (nothing against the Linke/ Staeck book).

Frankly, I'm not here to give you my CV.

In short: I grew up in a family who's side-business was breeding fish during pretty much the whole of the 1990s. I successfully (success is not measured in breeding success in my book) keep blackwater species in biotope tanks for some years now. And I help out a group of people in my area getting breeding projects of black and clearwater species going regularly.

And for the record: I despise domestic forms of A. cacatuoides.

If that's not enough for you, say so now.

 

[MacZ]

I just realized how snarky this could come across. That was not intended. Sorry if It might have offended.

 

[Apistoguy52]

No worries. I think that makes it clear that I’m unlikely to extract anything from your bag of blackwater breeding tricks.

Apologies if I’ve offended, I should be less sharp and more supportive of folks that are taking up Apistogramma. This is a wonderful forum, with many very experienced apistophiles. I think you’ll find a little less pontification, and being a bit less dogmatic will serve well moving forward in the hobby. The most valuable lesson I’ve learned from Apistogramma, is that what works/doesn’t work is far more important than doing what is “technically” correct. Apistogramma can be quite the paradox fish at times.

Cheers!

 

[MacZ]

You got a PM.

 

[Samson&Delilah]

Bummer….I really thought I would be able to keep sandbar Apistogramma, in a sandbar-ish biotope. Suppose I still have a good bit of time before fish may arrive, so there’s still time. A. psammophila are surprisingly tough to come by.

Macz-
I’m not terribly concerned about meeting the specific definition of blackwater, my only concern is creating water chemistry that would allow reproduction. Faux-blackwater is perfectly fine with me. Of the 100ppm tds present, I’d wager the bulk is GH, little sodium, more magnesium, and the remainder in calcium. How much softer would I need to make it to get blackwater species eggs to hatch?

Thanks!

KH is more important to eggs hatching than GH, you’d need a test tube based KH test. You’d need to keep it at 1 ish but to be honest I wouldn’t even attempt that in a new setup as you’ll always have trace amounts of ammonia / nitrite so wouldn’t be suitable for apistos. As far as wild vs aquarium habitats go if you’re putting territorial fish in a tank and want them to breed I’d recommend dividing the tank into thirds with wood, plants or other decor. Even if no dither fish. That setup would be stressful for them