Any Chili Rasbora breeding tips?

[Mr Gumby]

Hi folks,

I'm looking at setting up a breeding tank for my chili's

My tap water is 7.3 to 7.4 PH and very hard so I'm wondering if I use an RO blend to bring it down to PH 7 and the hardness just enough to maintain PH stability or go down the rain water root to get it to acidic PH.

If I use rainwater how would I get enough stability without raising PH or is it just a case of frequent water changes?

In short has anyone had success at a PH of 7 as that would make life easy 🙂

[TheSwissAquarist]

On 10/20/2022 at 3:21 PM, Mr Gumby said:

Hi folks,

I'm looking at setting up a breeding tank for my chili's

My tap water is 7.3 to 7.4 PH and very hard so I'm wondering if I use an RO blend to bring it down to PH 7 and the hardness just enough to maintain PH stability or go down the rain water root to get it to acidic PH.

If I use rainwater how would I get enough stability without raising PH or is it just a case of frequent water changes?

In short has anyone had success at a PH of 7 as that would make life easy 🙂

A fish friend managed to breed strawberry rasboras (which are chilis just without the fun color) and me said that Java moss and other fine leaved I plants are key if you want to passively breed them.

RO water or rainwater should be OK.

Good Luck and keep us posted!

[Traumfahrer]

Interesting topic, it's really hard to breed Chili Rasboras (in normal western aquaria conditions that is).

Apparently in SE Asia, Indonesia it is a thing to just throw some buckets of leaves in a big container, filled with rainwater and adding some Chilis, leaving it outside in the sun and voilà, after a few weeks it is full of fry of all sizes.

Only saw very few cases where people managed to get some fry in aquariums however. Supposedly that doesn't really happen above a pH of 6.5 and low hardness, although I know of one case.

Chilis are egg scatterers and will prey on their offspring. They only drop a few eggs a day however, further complicating things. The fry is so small, it can only feed on infusoria for quite some time. I've read suggestions to add enough leaves to grow a good amount of biofilm and microorganisms on, they will feed on that.

 

Check the Boraras subreddit on Reddit:

https://www.reddit.com/r/Boraras/

Have a look at the about page, the "Miniature Jewels" something article has some breeding tips too. Should also be able to find 2 or 3 posts from people that managed to get fry, explaining it.

On 10/20/2022 at 4:33 PM, TheSwissAquarist said:

A fish friend managed to breed strawberry rasboras (which are chilis just without the fun color)

Not exactly, Strawberries (Boraras naevus) are a clearwater species (from Malaysia) that live in 'harder' and less acidic waters than Chilis (Boraras brigittae) that are a blackwater species (from Borneo) that live in super softwater and acidic environments. (Also they inhabit slow flowing forestry peat swamp rivers with basically no vegetation, just leaves etc.)

Obviously they share a lot of characteristics being in the same genus (Boraras) but it's a wrong assumption that they're equally easy to breed imo (or that they thrive in the same environments).

[cavdad45]

I've nevr tried, but I watch lots of youtube and theire are a lot of videos on breeding and fry care

[Traumfahrer]

On 10/20/2022 at 8:42 PM, cavdad45 said:

I've nevr tried, but I watch lots of youtube and theire are a lot of videos on breeding and fry care

I don't think that is true, I know of only one that has some info on breeding them successfully. Can you link the ones you have in mind?

[TheSwissAquarist]

On 10/20/2022 at 7:50 PM, Traumfahrer said:

Not exactly, Strawberries (Boraras naevus) are a clearwater species (from Malaysia) that live in 'harder' and less acidic waters than Chilis (Boraras brigittae) that are a blackwater species (from Borneo) that live in super softwater and acidic environments.

Thanks for correcting me! 

[tolstoy21]

On 10/20/2022 at 9:21 AM, Mr Gumby said:

My tap water is 7.3 to 7.4 PH and very hard so I'm wondering if I use an RO blend to bring it down to PH 7 and the hardness just enough to maintain PH stability or go down the rain water root to get it to acidic PH.

If I use rainwater how would I get enough stability without raising PH or is it just a case of frequent water changes?

I have never bred Chili Rasboras, but I do keep them cause they are awesome fish! and because I use them as dither fish in some tanks I keep very acidic for certain Apistogramma species.

I have the Ph in those tanks down around 4.6 and the Chilis do fine. Do they breed in there? Maybe? However, if they do, their fry are sure to get eaten. 

Either way, I do about a 25% water change (with RO water) every week or two and they do well thus far without issue.

I don't know if this is the correct Ph range for breeding them, but I can attest to the fact that they are Ok at very low Ph ranges in water with little to no mineral hardness.

My tanks are blackwater, caused by the addition of peat (I keep Fluval peat pellets in a box filter) and oak leaves and bog wood. That, plus using straight RO water keeps things very low. I'm not sure I could drop the Ph further if I wanted to. I'm also not sure one needs to worry about the Ph crashing in blackwater setups, as it's already intentionally crashed.  I stress 'not sure' here, but trust me, if I could get the Ph to run a little bit lower, I would! 

Anyway, long story short, this species can tolerate a very low Ph, so I wouldn't worry too much about that as you consider breeding them.

Edited October 22, 2022 by tolstoy21

[Mr Gumby]

So latest update,

I've moved a dozen chili's to my 5-gallon RCS tank for conditioning. They're getting live daphnia, live BBS, decapsulated BBS as I only hatch live every other day, micro worms and vinegar eels.

The great thing about these tiny fellas is they still take my fry foods which keeps the cultures ticking over nicely.

I have blended in some rainwater just to get the PH somewhere near neutral but with enough GH and KH to keep the RCS happy.

Oddly I've seen two Chili's constantly scanning the substrate and picking at something (my 50-year-old eyes aren't good enough to see what it is). I'm hoping eggs but it could just be bits of food.

In a perfect world the moss balls, java moss, star grass and guppy grass in there would provide enough cover for any fry to hide and eat if they'd actually hatch at current water parameters but who knows.

Next thing is I'm going to try dropping a Tupperware in with some java moss and gravel like I do with my CPD's and if they are dropping eggs, I might have half a chance of spotting them. If that fails, I'll break out another of my 5 gallons and move the adults on to even softer water

exciting times!

 

[Rube_Goldfish]

On 10/22/2022 at 7:02 AM, tolstoy21 said:

I have the Ph in those tanks down around 4.6 and the Chilis do fine.... [T]rust me, if I could get the Ph to run a little bit lower, I would!

I thought I'd heard that nitrifying bacteria/archaea can't work as a biofilter below something like 5.0 pH. I don't know if they're supposedly dead at that acidity or dormant or just metabolize too slowly to be an effective biofilter, but if that's the case, how do you prevent ammonia build up at 4.6? Just frequent water changes? Will plants grow at that level?

[tolstoy21]

On 1/11/2023 at 8:28 PM, Rube_Goldfish said:

I thought I'd heard that nitrifying bacteria/archaea can't work as a biofilter below something like 5.0 pH. I don't know if they're supposedly dead at that acidity or dormant or just metabolize too slowly to be an effective biofilter, but if that's the case, how do you prevent ammonia build up at 4.6? Just frequent water changes? Will plants grow at that level?

You know, to be honest, I knew that fact about low PH and biofilters, but then forgot about it and never thought about it in terms of these aquariums.

Currently I have 2 aquariums running at about 4.5ish. One has had fish in it for 2 years running. In the other, fish have been in it about 9 months. I've spawned and grown out two batches of fry at that Ph, but after a month's time I start the process of acclimating them slowly to my tap water. The majority of my other aquariums run between 5 and 6.6.

I keep java fern and moss, anubias and crypts in these tanks (the crypts are in terracotta pots). The crypts melt at that Ph, but then slowly start to make their way back, but never really get going. The anubias and java fern does fine. Does it thrive? I dunno. I move plants around a lot. So they don't spend their lives in those conditions. But they also don't take a nose dive like my crypts do.

I don't really change a ton of water on my 'blackwater' aquariums. Maybe 25-50% every week or two (is that a lot?). And I have never thought to test for ammonia. (I'll actually do that tomorrow!). But, I have also never lost any adults or fry so I just assumed things were humming along.

If the biofilter just takes longer to establish, rather then not establishing, then that works out fine, because once my tanks are running, I don't typically tear them down. They have the luxury of time to get 'seasoned'. I typically let them grow pretty significant algae layers on their sides and back.

So the answer to your question is: "Hmm, good point. I dunno. I forgot all about ammonia!"

🙂

 

 

[Rube_Goldfish]

If it works, it works! I'll be curious to see the results of your ammonia test, but I'm guessing it'll be low somehow. Or maybe at that low pH it's all ammonium and no big deal? Life, uh, finds a way!

[tolstoy21]

On 1/11/2023 at 10:13 PM, Rube_Goldfish said:

If it works, it works! I'll be curious to see the results of your ammonia test, but I'm guessing it'll be low somehow. Or maybe at that low pH it's all ammonium and no big deal? Life, uh, finds a way!

Just tested my tank that has the lowest Ph and that I've also been kind of lackadaisical (aka negligent) about changing water. I think I maybe changed 25% of its water in the last month (this is a guesstimate). Ph sits between 4.2 and 4.5 in this aquarium. It's been up and running 2 years, has tons of leaf litter, bog wood and a box filter full of peat pellets. Only plant in it is one large anubias barteri.  This is a 20g with 2 zebra acara in it (both fish are about 3-4"). 

Test results . . . . drum roll please . . .  zero ammonia!

My grow outs for my apsitogramma abacaxis start out that low, but I do switch them over to auto water change a few weeks after the fry are born. From that point forward, the Ph sits in the low 6s and they get like a 10% water change daily.

Edited January 12, 2023 by tolstoy21

[Rube_Goldfish]

On 1/12/2023 at 8:07 AM, tolstoy21 said:

Just tested my tank that has the lowest Ph and that I've also been kind of lackadaisical (aka negligent) about changing water. I think I maybe changed 25% of its water in the last month (this is a guesstimate). Ph sits between 4.2 and 4.5 in this aquarium. It's been up and running 2 years, has tons of leaf litter, bog wood and a box filter full of peat pellets. Only plant in it is one large anubias barteri.  This is a 20g with 2 zebra acara in it (both fish are about 3-4"). 

Test results . . . . drum roll please . . .  zero ammonia!

My grow outs for my apsitogramma abacaxis start out that low, but I do switch them over to auto water change a few weeks after the fry are born. From that point forward, the Ph sits in the low 6s and they get like a 10% water change daily.

Huh, that's really something. If the microbes aren't eating the ammonia, and the plants aren't eating it,* and you're not removing a significant amount via water changes, then I wonder what's happening to it. That seems like a low stocking, which I guess helps, but my layman's understanding is that it would only slow down accumulation, not eliminate it.

My next guess would be either that the conventional wisdom about low pH harming a biofilter is incorrect or overblown or that there are other acid-loving nitrifying microbes. But obviously I don't have the wherewithal to test that either way. The mystery continues!

Thanks for testing and reporting back!

*I'm assuming that a single Anubias isn't consuming enough ammonia to account for it, but maybe if it's big enough? But no, they're slow-growing plants, so I doubt it.

Edited January 12, 2023 by Rube_Goldfish

[tolstoy21]

@Rube_Goldfish

 

Ok, so I grabbed bunch of scientific articles on the topic from my work, and they are a bit to 'heady' for me to process fully this early in the morning. I'll have to look over them more slowly later to fully grasp them fully, but the basic gist of ammonia and PH is summarized below

Please, anyone, if I am getting any of this science wrong, please correct me so as to add to our knowledge as it applies to our hobby.

Ok, here is what I understand from what I read this morning, minus a lot of scientific detail . . . .

As the Ph lowers, ammonia converts to ammonium. As Ph rises, the reverse happens. To keep it simple, think of ammonium is the non toxic form of ammonia.

As we know, the introduction of alkalinity to the water in the form of bicarbonates raises the Ph. But it also tips the ammonium/ammonia scale in the favor of ammonia (also called free ammonia). This is stinky ammonia we are all very familiar with. (I'm still working on grasping the concept of why and how the conversion happens as a natural process).

The nitrifying bacteria we normally discuss in terms of the aquarium cycle rely on both free ammonia and mineral carbon to be sufficiently present as an nutrition source. As the bacteria consumes these, the Kh (and this Ph) lowers but this also starts off the wondrous 'nitrogen cycle' we all know and love. This also why the increase of free ammonia (waste) can lead to Ph crashes.  And, it's also why we seek a balance in our aquariums--to keep this process humming along in a way that keeps our established bacteria colonies fed and keeps or water parameters, in terms of Kh and Ph, stable. 

Now, at low Ph levels, microorganisms like nitrobacter have a hard time (or cannot) establish due to the lack of sufficient carbon and free ammonia.  However, this lack of free ammonia is also what keeps the tank from becoming toxic, as the ammonia is bound up in its alternative form, ammonium. Thus in a low Ph environment, the normal biofilter we associate with a more typical Ph level is not present, but neither is the free ammonia in sufficient quantities.  It would seem there is also a nitrification process for ammonium as well, but I haven't yet read any details on it.

My one take away from all of this is that sudden shifts upwards in water alkalinity can result in either a sudden transformation of ammonium to ammonia (I've seen this referred to online as an ammonia bomb!).  On the other hand, the depletion (or lowering) of water alkalinity can negatively impact the existing biofilter that relies on it.

 Anyway, that was a lot, but I though it was good information to share.

And please, do correct me on anything that I'm wrong about. I am certainly not a scientist, nor chemist, nor do I possess any expertise at all on this topic beyond what I read this morning. But I also ask, in correcting me, be nice and not the typical internet jerk who likes to make people fee small when they are wrong about something!

[Rube_Goldfish]

So the biofilter in your tank is smaller or non-existent in a way that makes a big difference, but it doesn't matter quite so much because the fish waste is in the safer ammonium form rather than free ammonia, because the pH is so low? That makes sense, though I guess the ammonium would build up over time, too; I guess that's where the notification process for ammonium in a low pH environment comes in. I wonder if it's microbial or chemical.

Thanks so much for following up on this and diving into it! I'm no chemist or scientist either, just a curious layman. I really appreciate you doing the heavy lifting!

[tolstoy21]

On 1/13/2023 at 9:56 AM, Rube_Goldfish said:

So the biofilter in your tank is smaller or non-existent in a way that makes a big difference, but it doesn't matter quite so much because the fish waste is in the safer ammonium form rather than free ammonia, because the pH is so low?

Yes, the literature suggests that ammonium is non-toxic, and that the ratio of ammonia-to-ammonium has a direct relationship to the Ph. As Ph increases or decreases the ammonia/ammonium ratio of the "TAN" (total ammonia) shifts away from one, toward the other.

However, I kind of got the feeling that the biofilter is also different at low Ph levels, and that ammonium is processed as well, but I'm trying to get more information on this.

My current 'understanding' is that the biofilter of a tank with a Ph of 7 won't be the same as a biofilter in a tank with a Ph of 5.  So sudden changes to the availability of things like Kh and/or ammonia/ammonium would then somewhat disrupt or change the makeup of this biofilter which would have an impact on the aquarium's ammonia levels until the biology of the tank can catch up.  This is probably why the advice to not chase a specific Ph and just keep it stable is often the most useful advice a beginner can get. 

I also get the feeling that the presence of Kh also starts the process of changing ammonium to ammonia by causing it to shed or attach a hydrogen ion, but this is where I need to do some more reading. But this is to say that Kh plays multiple roles in this process that are chemical as well as biological. So its not as simple as Kh feeds bacteria. 

I am sure I'm getting some of this completely, wrong, but that's how things seems to work to me based on the little bit of reading I did thus far on how Ph relates to ammonia in an aquarium. Going to keep looking into this until I feel like I completely grasp it or come to the conclusion that I will never fully grasp it!   🙂

Edited January 14, 2023 by tolstoy21

[Rube_Goldfish]

That seems like a sound hypothesis to me. Isn't it funny how the questions at the beginning are "this isn't working, why not?" and then they evolve over time to "this is working, but why?"

[tolstoy21]

On 1/13/2023 at 10:28 AM, Rube_Goldfish said:

That seems like a sound hypothesis to me. Isn't it funny how the questions at the beginning are "this isn't working, why not?" and then they evolve over time to "this is working, but why?"

Yeah! This is how I learn stuff and what I find exciting!

I get a bug in me that makes me want to understand something and then I can't put it down until I understand it. Luckily I have access to a lot of research materials via work. However, I often lack the background to immediately (or ever) understand a lot of them.

A lot of the research I came across this morning was conducted for studies involving waste water management, so understanding the jargon of that discipline will take me some time.

There are a few aquarium hobby articles written on the subject available on the www, but they don't go deep enough into the 'why' or 'how' for me to alleviate my itch!  Sometimes it's not good enough to know that a thing occurs . . . . I NEED TO KNOW HOW and WHY it it occurs, otherwise the itch persists!

But that's just me. I'm not 100%, as they say, neurotypical!

🙂

[tolstoy21]

@Rube_Goldfish

Ok this short web article probably best articulates in an easier to read form what happens to ammonia in aquariums with low Ph --  https://aquasprouts.com/blogs/everything-aquaponics/ammonium-trap-its-not-the-ph-drop-that-get-you

This article is super long and very 'science-y', but has a wealth of information about all the bacteria involved in the nitrification process -- https://www.climate-policy-watcher.org/nitrification/introduction-to-nitrification.html

Edited January 14, 2023 by tolstoy21

[Rube_Goldfish]

I didn't know the bit from the first article about the extra hydrogen ion from the nitrification process contributing to the gradual acidification of aquariums. It all reinforces the importance of stability, though, huh? Thanks for finding and posting it!