24*12*10 inch blackwater tank...stocking suggestions?

[Joshaeus]

Hi everyone! I have recently set up a partially filled 20 gallon high blackwater tank...here is the tank;

It needs to cycle, but it is using straight RODI water and has a PH of about 6.5 currently. When it is thoroughly cycled, would it basically be suitable for a pair or trio of ANY apisto, or are there some that would not do well in such soft water? Also, what other dwarf cichlids would do well in this tank? I am thinking of using CO2 to lower the tank's PH if I happen to get a species that wants a lower PH than 6.5, as I've had issues reducing the PH by other means in soft water tanks before. Thanks

 

[MacZ]

I gave my opinion already on fishlore.

Be careful with CO2, it is rather impractical to keep a constant pH unless you have a reserve container of CO2 at hand at all times and can react on very short (less than 1 hour) notice any time of the day.

For Apistogramma a single specimen might be the best choice except you can separate a pair at any time.

Nannacara might work, or as discussed in the other forum: A trio of Dicrossus.

 

[anewbie]

I'm not sure the fluctuating ph from co2 will be an issue since the kh and (i believe) ion level will remain constant. I'm not sure i would put the nannacara in a 20 high - i had mine in a 20 long and now in a 40b - I'd be a wee bit concern the 20 high might cause issues if they breed due to limited horizontal space. Also nannacara is not a fish that require blackwater. If you are going to go to the effort of a true black water i'd go for a fish that can take advantage of it.
--
Also i think in a smaller tank i would look for a fish in which you have a m:f bond to make life easier as both parents are more likely to take advantage in the raising of the young and there is less bickering between m:f during brooding. An example would be apistogramma nijennsi.

 

[MacZ]

Also nannacara is not a fish that require blackwater.

I forgot that the two species I was thinking of are now in the Ivanacara genus. And those are too aggressive for the tank size.

I'm not sure the fluctuating ph from co2 will be an issue since the kh and (i believe) ion level will remain constant.

As pH, KH and CO2 are in constant flux CO2 will start to gas out within a few hours after the bottle running out as there is no KH to bind to. But it has the advantage to exactly dial in the pH.

 

[Joshaeus]

I gave my opinion already on fishlore.

Be careful with CO2, it is rather impractical to keep a constant pH unless you have a reserve container of CO2 at hand at all times and can react on very short (less than 1 hour) notice any time of the day.

For Apistogramma a single specimen might be the best choice except you can separate a pair at any time.

Nannacara might work, or as discussed in the other forum: A trio of Dicrossus.

I completely forgot you were on this forum! Oops I was going to use a yeast reactor, which I have used in the past...I could rig a new one up very cheaply and efficiently, but I can skip the CO2 if that would still not be stable enough.

I'm not sure the fluctuating ph from co2 will be an issue since the kh and (i believe) ion level will remain constant. I'm not sure i would put the nannacara in a 20 high - i had mine in a 20 long and now in a 40b - I'd be a wee bit concern the 20 high might cause issues if they breed due to limited horizontal space. Also nannacara is not a fish that require blackwater. If you are going to go to the effort of a true black water i'd go for a fish that can take advantage of it.
--
Also i think in a smaller tank i would look for a fish in which you have a m:f bond to make life easier as both parents are more likely to take advantage in the raising of the young and there is less bickering between m:f during brooding. An example would be apistogramma nijennsi.

Yeah, the CO2 has little to no effect on KH or other ions. Don't blackwater habitats experience sudden fluctuations in PH anyway due to large storms (and the absence of buffering to moderate them)?

EDIT; What about wild type blue ram cichlids? I understand that they pair bond. Also, would any african dwarf cichlids work? (Obviously riverine species, not rift lake species that would quickly keel over in this tank)

 

[MacZ]

I was going to use a yeast reactor, which I have used in the past...I could rig a new one up very cheaply and efficiently, but I can skip the CO2 if that would still not be stable enough.

For this I would actually use a complete CO2 injection with a pH-controller (pH meter + injection controller), as you can't set the yeast reactor to a certain level.

EDIT; What about wild type blue ram cichlids? I understand that they pair bond. Also, would any african dwarf cichlids work? (Obviously riverine species, not rift lake species that would quickly keel over in this tank)

Rams are a clearwater species and don't require that low pH.

There are no actual dwarf cichlids in the Rift Lakes, although they say shellies are. But only in size and being cichlids.
So for sure species from the upper Niger and the Congo basin might be interesting. But those are all really hard to get recently, not only due to the pandemic but also due to political instability. The actual blackwater species are hard to get and dang expensive.

 

[dw1305]

Hi all,

I am thinking of using CO2 to lower the tank's PH

There isn't any advantage to this. It is a bit of a strange one but adding CO2 just changes the carbonate ~ CO2 ~ pH equilibrium point, by <"adding more Total Inorganic Carbon (TIC)">.

You also have the risk of accidentally asphyxiating your fish.

Yeah, the CO2 has little to no effect on KH or other ions. Don't blackwater habitats experience sudden fluctuations in PH anyway due to large storms (and the absence of buffering to moderate them)?

They do. The pH in soft water is never stable, I look at pH changes in terms of changes in ionic composition and buffering. In hard water you need large changes in ionic composition to cause small changes in pH, and in soft water small changes in ionic composition cause large changes in pH.

I know they aren't cichlids but a pair of one of the blackwater Betta spp. might be more suitable for the tank?

cheers Darrel

 

[MacZ]

I know they aren't cichlids but a pair of one of the blackwater Betta spp. might be more suitable for the tank?

Agree, maybe some B. channaoides, B. macrostoma or B. albimarginata. I know the OP had at least chocolate and licorice gourami before. (Btw, why are those all named after candy? )

 

[Joshaeus]

Agree, maybe some B. channaoides, B. macrostoma or B. albimarginata. I know the OP had at least chocolate and licorice gourami before. (Btw, why are those all named after candy? )

Macrostoma is too large for a 20H (in practice being used as a 15 gallon) in my opinion, but LOTS of other wild bettas would work (B. dimidiata seems particularly attractive to me). I have not kept any of the chocolate gouramies but have kept two different Parosphromenus species...my P. nagyi died off within a few months of purchase (likely due to me acclimating them incorrectly...I got four, two died within a week, and the remaining pair couldn't stand each other and never bred), but my P. species 'sentang' (which started as a trio) thrived and bred for several generations in a 5 gallon tank, with several males holding territories and displaying to females at the colony's peak.

 

[MacZ]

Macrostoma is too large for a 20H (in practice being used as a 15 gallon) in my opinion, but LOTS of other wild bettas would work (B. dimidiata seems particularly attractive to me). I have not kept any of the chocolate gouramies but have kept two different Parosphromenus species...my P. nagyi died off within a few months of purchase (likely due to me acclimating them incorrectly...I got four, two died within a week, and the remaining pair couldn't stand each other and never bred), but my P. species 'sentang' (which started as a trio) thrived and bred for several generations in a 5 gallon tank, with several males holding territories and displaying to females at the colony's peak.

Oh it was two species of Parophromenus? Might have mixed something up then. In my opinion the genus is the highest level in blackwater fishkeeping, so if you had success with them, everything else should be comparatively easy. Which doesn't help much with decisionmaking...

 

[Joshaeus]

Oh it was two species of Parophromenus? Might have mixed something up then. In my opinion the genus is the highest level in blackwater fishkeeping, so if you had success with them, everything else should be comparatively easy. Which doesn't help much with decisionmaking...

I have long been nervous about trying any of the chocolate gouramies because I keep reading that they are highly quarrelsome, to the point that they get each other sick from stress and the group often dies as a result. Licorice gouramies seem relatively easygoing and disease free by comparison.

 

[MacZ]

Licorice gouramies seem relatively easygoing and disease free by comparison.

Disease-free yes. Easygoing... yeah, well, I know somebody who is part of that conservation/breeding project for the near-extinct licorice gourami species, the water parameters seem to have to fit to a T or things go bad as you described with losing them within a shorter period of time. Which makes sense, considering many of those come from pH below 4 or even below 3.
Had a case of sick chocolate gourami lately, all had an unidentifiable parasite, owner lost them over the course of only a month.

 

[Joshaeus]

How do you get the PH that low and keep it there? I remember using sodium bisulfate in the past for the P. species sentang tank, resulting in a PH in the low 4's after the 40% weekly water change (which climbed to the mid 4's over the week), but I do not remember how much I used.

 

[MacZ]

100% RO/DI, peat cannon and finished off with a dash of hydrocloric acid + peat as substrate and leaf litter in tanks of no more than 30 liters each. Basically purest water feasable with his gear stuffed with acids.
I can understand peat, it's just not sustainabe and I don't want to work with chemicals.

Though with botanicals and RO my lowest level was only at 5.6 and that's plenty for my aspirations. I keep it near 6.0, which has proven to be most stable in my setup. I neither want to breed nor keep extreme species, so I'm content with that.