40 Gallon Tank Stocking help for leaf litter tank

[SuspiciouslyFishy]

Hi all!
So, it will be about a month of making sure things are stable with what I already have before adding fish, but I've been thinking a lot about the stocking.
Currently I have a 15 gallon with about 10 or 11 otocinclus catfish, 3 neon tetras and a number of ramshorn and bladder snails. I plan to move them to the 40 gallon tomorrow, then wait a month for things to settle.
Plan for the 15 is to heavily plant it with a lot of the plants I've collected over time, and let the snails have at it until I've finished stocking the 40 gallon. Then I'll add 10 male guppies, and I think that's that sorted.

The plan for the 40 is a bit less certain though. I know only what fish I like, and have a list of hopefuls. I don't plan to get any more neons because they keep dying on me without explanation (not a water quality thing because the otos have been totally fine). For the scape, I want to go heavy on driftwood and botanicals like catappa leaves and alder cones. Amazon frogbit and red root floaters on the top, little bits of java moss and fern, limnophila in the background (covering up equipment, etc.) and maybe helanthium under spots where the driftwood would prevent leaf litter from accumulating. So not overly heavily planted. Just to set the scene.

Otocinclus are my favourite fish, followed closely by cory cats. I know I want shrimp, probably red cherry shrimp (which may or may not be red themselves). And I'm also considering cardinal tetras. However, I don't want to overcrowd. I've felt despondent for a while that I haven't been able to provide the best environment in a 15 for fish as active as tetras and so on. So I need to be sensible with my numbers. Maybe leave out the cory cats entirely until I get my next dream tank!

So, numbers:

Oto- 10
Neon- 3
Cardinal- 15
Pygmy cory- 10
RCS- 10
Plus ramshorn and bladder snails

OR
Oto- 15
Neon-3
Cardinal- 20
RCS-10
Plus snails

What do you think? Which should I go for? And would you forsee any issues? I based this on playing with numbers on aqadvisor but I know that isn't an absolute guide for stocking (aqadvisor placed these lists at 84 and 85% stocked).

 

[ProudPapa]

I like the plan with the Corydoras pygmaeus, I'm not so sure about the cardinal tetras. They may work for you, but I had the same problem with them that you're having with neon tetras.

Have you considered black neon tetras? Contrary to what you'd think from the name, the dark band is actually a dark blue, and it looks really good with the lighter blue band above it.

 

[Blacksheep1]

I wouldn’t up the ottos to 15. Leave them at the 10 you have. If you can picture the tank Without any tetras , you don’t have much movement as such. The Pygmy’s would add bottom interest perfectly , so a shoal of fish would fit perfectly for upper level movement.

It’s quite common to have issues with neons as they are very inbred unfortunately.

what’s your ph ? There’s several tetra options, cpd’s, rasboras etc. with more info on your water it’s easier to choose what fits better !

 

[SuspiciouslyFishy]

I wouldn’t up the ottos to 15. Leave them at the 10 you have. If you can picture the tank Without any tetras , you don’t have much movement as such. The Pygmy’s would add bottom interest perfectly , so a shoal of fish would fit perfectly for upper level movement.

It’s quite common to have issues with neons as they are very inbred unfortunately.

what’s your ph ? There’s several tetra options, cpd’s, rasboras etc. with more info on your water it’s easier to choose what fits better !

Thanks! My pH is pretty low, although I do need to double check as I moved recently. But as I only moved 10 minutes down the road, I can probably presume it's not much different to the 6.6 I had before.

I hadn't considered black neon tetras, but I definitely could consider it. Something that would thrive in the low ph, and add interest to the upper levels and not be too inbred is what I'm after in the niche the cardinals would have filled.

 

[MacZ]

Leave the shrimp and snails out!

Some snails are never a problem but with leaf litter you will have an overpopulation soon as if you were overfeeding. The shrimp and snails will also be a hard competition for the Otocinclus. Besides, the habitat you are going to reproduce has virtually no snails or shrimp.

Speaking of Otocinclus: I would leave them in the old tank for a while until the new tank is fairly established (3-4 months absolute minimum!) and not stock up until they are acclimated in the new tank (2-3 months after moving them to the new tank).

Next problem would be the Corydoras.
Corydoras share places of origin with Otocinclus and Cardinals, but they also prefer a different part of the habitat, as they like to stay in the stronger flow areas with open sand and maybe some branches used as cover and only little leaf litter getting stuck on the branches.
The leaf litter beds are home to dwarf cichlids, banjo catfish, Platydoras catfish instead. Otocinclus stay among branches and twigs, and cardinal tetras roam freely above all of this.
So for the Corydoras, make sure there are enough open areas left.

I would also not mix neons and cardinal tetras. As said above neons tend to be in- and overbred and prone to disease. Diseases that can easily also kill cardinal tetras. Your surviving neons might still harbour such pathogens. Give the neons a final home in another tank instead.

Concerning the water: Please go get a testkit for GH and KH and maybe also a TDS meter. Otherwise the longterm monitoring of a botanical method tank's parameters becomes problematic.

And ultimately: Scratch aqadvisor from your bookmarks. The site is riddled with problems and bioload works differently in botanical method aquariums.

Maybe take a look at my article, I'm sure many questions will be answered:
Blackwater: Basics and FAQ - Aquarium Article

Edit: One more thing - make sure there are no seeds left in the alder cones. They will swell and start to decompose, but while otherwise you want decomposition of the dead plant material, the seeds are rich in nutrients and may cause fouling. Usually botanicals and leaf litter have minimal amounts of nutrients left, that's why botanical method aquariums work in the first place. Too much nutrients and the whol thing tilts into disaster.

Edit #2: And some ideas for other species of fish -
Tetras: Hyphessobrycon herbertaxelrodi, H. amandae, H. sweglesi, H. amapaensis, Axelrodia riesei, Paracheirodon simulans, Hemigrammus erythrozonus.
Pencilfish: Nannostomus marginatus, N. unifasciatus, N. eques
Others: A single male Apistogramma, Nannacara or Dicrossus might also be of interest.

For plants: I recommend an orientation towards the surface. Besides floaters use emersed plants like Hydrocotyle leucocephala or "cheaters" like Nymphaea lotus. Everything that can use the light in the upper 10-15cm under the surface and/or the CO2 above the surface will do better than anyhing planted in the substrate.

 

[SuspiciouslyFishy]

So, the snails are not an option to leave out. They are already in both tanks, moved with decor I used in the old tank. Unless I kill them off, I have snails. I could try to kill them off? But then that might harm otos when they're added later (I've read that some substances that kill snails will linger in the substrate). It's probable that I'll just have to go on a long-term manual-removal rampage, adding cucumber and then taking it out once it's covered.

Otherwise, I read your post and I'll think carfully about whether it's something I want to pursue. I like the idea of "cheat" plants and floating plants, and have some epiphytes I can tie to driftwood higher up. I'll get a tds meter and try to also get GH/KH kits. I remember at the beginning of my journey into fishkeeping (about a 30 minutes drive from here in the same city), I had test strips (bad, I know, I have the API liquid kit now) and those measured KH/GH. KH didn't even register on them. Whatever it is, I suspect it's really low.

It sounds like the fish will have to be in their old tank for a while though, so I think today I'll scape it properly with the plants that just wouldn't survive in the blackwater idea and let them have at it for a bit while I figure things out. They've been in there for almost a year already, so a few more months won't hurt. I could run a second filter in there in the meantime to provide a culture I can use to jumpstart the cycle in the bigger tank when the time comes. Although with the lower pH in blackwater systems, that might be futile.
I'll also have to rethink my stocking. Hmm... It's a lot of food for thought. But I went into this knowing that I might have to rethink stocking. I mostly used aquadvisor to come up with ideas for numbers for my favourite species (I did do some other research on reccomended pH and temperature and so on), along with numbers for a schooling upper level fish I could use to add movement up there. It wasn't a set in stone thing.

That said, I'm not sure how blackwater it would actually get. My driftwood all already leached it's tannins. And in other setups leaves alone haven't been enough to tint the water very much at all. I added 8 catappa leaves to the 15 and barely saw a hint of it.
I'm going into this mostly just wanting to provide a good environment for the otos. With something to add a bit more visual interest in the upper levels. The blackwater is mostly because they come from blackwater and seemed to really enjoy leaves when I added them before.

 

[MacZ]

So, the snails are not an option to leave out. They are already in both tanks, moved with decor I used in the old tank. Unless I kill them off, I have snails. I could try to kill them off? But then that might harm otos when they're added later (I've read that some substances that kill snails will linger in the substrate). It's probable that I'll just have to go on a long-term manual-removal rampage, adding cucumber and then taking it out once it's covered.

You are correct. Good snail hunting then. Your only chance to keep this under control. If you stay persistent over a month or two you might even be able to pick them all out.

Otherwise, I read your post and I'll think carfully about whether it's something I want to pursue. I like the idea of "cheat" plants and floating plants, and have some epiphytes I can tie to driftwood higher up. I'll get a tds meter and try to also get GH/KH kits. I remember at the beginning of my journey into fishkeeping (about a 30 minutes drive from here in the same city), I had test strips (bad, I know, I have the API liquid kit now) and those measured KH/GH. KH didn't even register on them. Whatever it is, I suspect it's really low.

Test strips are completely fine, as long as you evade the typical user errors. There are no testkits available in the hobby that shine with true accuracy and precision. Strips are designed to tell you IF something is in the water or not and if so, whether it is too much or too little. Same (to a lesser extend) with drip tests.
If KH is really low, you are absolutely reliant on humic substances and mulm on the bottom, stabilizing everything.

Now before I answer to the rest, I'd like to make one thing clear: I'm not telling you to go full blackwater. But you are already going the route of the botanical method aquarium, meaning many factors of blackwater - or let's be more general: softwater - apply to your tank. You can learn many tricks from that.

It sounds like the fish will have to be in their old tank for a while though, so I think today I'll scape it properly with the plants that just wouldn't survive in the blackwater idea and let them have at it for a bit while I figure things out. They've been in there for almost a year already, so a few more months won't hurt.

Correct, a few months more are not a problem.

I could run a second filter in there in the meantime to provide a culture I can use to jumpstart the cycle in the bigger tank when the time comes. Although with the lower pH in blackwater systems, that might be futile.

No, that's pretty much exactly what I did when I upgraded my tank in January. In October '21 I took the filter media of my old internal filter, put them in an external filter and just let it run on the smaller tank until January. I also transferred as much botanicals, leaves and mulm as possible.
In softwater and low pH bacteria colonies will still grow. Just a little slower and a lot of the beneficial microorganisms live on and among the botanicals and the mulm. So basically a botanical method aquarium moves all these processes from the filter out into the open. And the animals thrive and benefit from it, as the biofilms foster infusoria and as such food.

I'll also have to rethink my stocking. Hmm... It's a lot of food for thought. But I went into this knowing that I might have to rethink stocking. I mostly used aquadvisor to come up with ideas for numbers for my favourite species (I did do some other research on reccomended pH and temperature and so on), along with numbers for a schooling upper level fish I could use to add movement up there. It wasn't a set in stone thing.

Take your time. I'd go with smaller species to be honest. They can be kept in appropriate numbers much easier.

That said, I'm not sure how blackwater it would actually get. My driftwood all already leached it's tannins. And in other setups leaves alone haven't been enough to tint the water very much at all. I added 8 catappa leaves to the 15 and barely saw a hint of it.

The visible humic substances ("tannins" is an established term by now, though factually wrong), tell you exactly one thing: Nothing.
All the material, wood, leaves, seedpods etc, keeps decomposing and while doing so release more organic acids on the long run, which keeps a certain influx going. I would recommend adding DIY extracts from alder cones and leaves with each water change and only add the leaves. The cones can be used for 2-3 brews if dried properly inbetween. This way you keep the humic substances coming which have pH-stabilizing properties in absence of KH. They replace the KH-based buffering system, stabilizing pH between 4 and 6.

I'm going into this mostly just wanting to provide a good environment for the otos. With something to add a bit more visual interest in the upper levels. The blackwater is mostly because they come from blackwater and seemed to really enjoy leaves when I added them before.

This is exactly how fishkeeping should work in my opinion, especially with wild caught fish like Otocinclus. Offer them conditions as close as possible to nature.

 

[SuspiciouslyFishy]

Thanks a lot! Honestly, I'm now strongly considering adding the otos (keeping the neons back), after I've established how I want it to look and have a good leaf litter going, and then going with only one other species (pygmy cories are still a possibility for that, I'll have to see what comes out with more research and figure out if there will be the bare sand for them to sift through in the scape). But it's still subject to change and input. I'll look more into plants as well.
What should I be looking out for with the KH/GH/TDS? I can get the kits and I notice that in the article, the values are quite low. But if they turn out to not be, or change over time, then what should I be doing about that? How should they change over time?

I'll add the cones and pods from my 15 gallon straight away, but keep future ones back to make a tea. I just steep it as if I'm making a cup of tea, right? I can keep a mug back for that specific purpose. And start trapping snails.

 

[MacZ]

Thanks a lot! Honestly, I'm now strongly considering adding the otos (keeping the neons back), after I've established how I want it to look and have a good leaf litter going, and then going with only one other species (pygmy cories are still a possibility for that, I'll have to see what comes out with more research and figure out if there will be the bare sand for them to sift through in the scape). But it's still subject to change and input. I'll look more into plants as well.

I would probably go with some smaller pencilfish and maybe a small group (1m/2-3f) of Poecilocharax weitzmani. This is just an idea, because they are just perfect for such a setup.

What should I be looking out for with the KH/GH/TDS? I can get the kits and I notice that in the article, the values are quite low. But if they turn out to not be, or change over time, then what should I be doing about that? How should they change over time?

I would first just see what you've got. Test your tap, test your tank. Then go from there.

My average parameters (after a waterchange) for reference:
pH: ca. 5 (KH too low for driptests, EC too low for pH-meter)
GH/KH: below detection
TDS: 30mg/l
EC: 60µSi/cm
My source water is pure RO with a TDS of 5 and EC of 11. I add 4-6ml of liquid full spectrum fertilizer and 2 liters of DIY humic extract after a waterchange, raising TDS to 40 and EC to 80.

I'll add the cones and pods from my 15 gallon straight away, but keep future ones back to make a tea. I just steep it as if I'm making a cup of tea, right? I can keep a mug back for that specific purpose. And start trapping snails.

Pods can and should be added, as they usually don't contain seeds anymore.
And yes, it's a bit like with tea. You can either do it right before the waterchange (which gives you a more light extract) or the night before and let it sit until use (which gives you a dark and more potent extract.). I use RO for this, as it is a better solvent than tapwater.

 

[SuspiciouslyFishy]

Honestly, having now moved the 15 gallon today. I need to do one or the other. I don't have the space for both. The desk should hold for an hour or two but I'll have to move them all over. I'll figure this out one way or another. I'll just have to go slowly with adding in botanicals and hope for the best. Or maybe switch plans and buy a load of plants instead.

 

[TClare]

Just a couple of things to add to the very helpful comments made by MacZ. I have a tank (240 litres) with a lot of branches and leaf litter, I do have ramshorn snails in there but they don't tend to overpopulate, their shells go white eventually (due to my very soft water) and they don't get very big. There are also 5 otos in there. Re plants. I find Vallisneria to be a good background plant. The leaves soon reach the surface so they get enough light. I think you will find with Limnophila that the lower leaves might start to die off. I do also have some Cabomba at one end of the tank, I planted it mainly in an area where the substrate is built up quite high and I keep this end free of floating plants, it seems to be doing OK. All these plants were taken from my other tanks, I would like to add a Nymphaea but the one I have doesn't seem to produce babies..

 

[MacZ]

Yeah, with ramshorns you can be lucky. With bladdersnails, though... I was mor focussed on those tbh.

 

[SuspiciouslyFishy]

Just a couple of things to add to the very helpful comments made by MacZ. I have a tank (240 litres) with a lot of branches and leaf litter, I do have ramshorn snails in there but they don't tend to overpopulate, their shells go white eventually (due to my very soft water) and they don't get very big. There are also 5 otos in there. Re plants. I find Vallisneria to be a good background plant. The leaves soon reach the surface so they get enough light. I think you will find with Limnophila that the lower leaves might start to die off. I do also have some Cabomba at one end of the tank, I planted it mainly in an area where the substrate is built up quite high and I keep this end free of floating plants, it seems to be doing OK. All these plants were taken from my other tanks, I would like to add a Nymphaea but the one I have doesn't seem to produce babies..

Yeah, I do remember that from the last time I tried to go botanical. I had many baby snails, but hardly any of them grew big enough to breed and most of their shells went white.
The bladder snails hitched in on some live plants.
Thanks for the input on ideas for plants!

 

[SuspiciouslyFishy]

I have done a bit of research, and while it will take a while to set up, I do like the idea of dwarf pencilfish and darter tetras. How many of each would you reccomend once I've built up the leaf litter and perhaps added some plants?

(Currently, I do still have those 10 otocinclus)

 

[MacZ]

How many of each would you reccomend

Nannostomus: 10-15
Peocilocharax: 2-3m/4-6f

Make sure to have plant thickets on the surface and structural leaf litter and twigs. The Otos should do well in the tank once it's really established.

 

[SuspiciouslyFishy]

Will do. I won't get any of them for a while until the leaf litter, twigs, and plant thickets are pretty established.
I hope they do well! Nothing makes me happier than seeing them munching on food or enjoying some leaf litter.