Stocking proposal for 125 litre (27g UK) – thoughts welcome!

[nobo]

Hi,

Relative newbie curious to have some thoughts on stocking ideas/recommendations for a new tank.

I have a Juwel Rio 125 litre with T5 lighting, “pimped” internal Jewel filter with 2kg of biogravel. Sand substrate over Tropica aquarium soil. Fairly heavily planted, nature style (vallis, java moss, java fern, anubias bateri, water wisteria and indian fern). pH 6.5-7. Tap water source is, I’m afraid, hard (London). Pond snails everywhere (perhaps I should get a handful of assassins?).

In term of stock I’m drawn to the more unusual (to an non-expert!) shaped fish. The following appeal in particular (suggested numbers in brackets), and (at least as I understand it) are all peaceful and should work as tank mates:

• Pearl Gouramis (1 M, 2F) – love these! Pretty much certain unless seriously inadvisable.

• Bristlenose plec/ancistrus (1) – interesting looking plus an algae eater and a size contrast to the other fish (is there another dwarf plec that’d be suitable instead?)

• Corys (5-6). For general tank cleaning duty! But what type? Perhaps bronze, pepper, or three stripe? Or pygmy (8). I assume (newbie alert!) that mixing types of corys means it no longer counts as a shoal (else I’d get a mixed shoal). However, might not be necessary or compatable with african dwarf frog (competition for food). I was considering Otos (4-6) instead, preferring their look and that they’re all-level fish; but Corys seem easier to look after and mean I can (hopefully!) avoid algae/keep tank clean!

• Khuli loach (acceptable minimum number? 2-3?) – Interesting fish and would help address the snails!

• African dwarf frog/congo frog (2 - max 3)

• Plus a shoal of mid-ish level fish:
  • I have some (9) glowlight tetras I could move over from a smaller tank (who’d probably appreciate the extra space) and maybe turn that into a multi breed shrimp tank (currently 5 amanos) … or something else (?). If the tetras stay put, I’d be looking for 1-3 top / top/mid or all level fish to go along with them (which also has 5 amano shrimp).
  • Else:
    • White cloud minnows (6); or
    • Three-lined pencilfish (Nannostomus trifasciatus)(6?); or
    • Threadfin rainbow fish (top/middle tank) (6)
    • Something else…?

• Elephant nose (1) –Interesting and usual. I’d love one of these too, but I suspect I'd be overstocking - since large and full bodied, uses up a lot of the available fish inches! Also perhaps too challenging re water parameters etc.

Any thoughts welcome – e.g. what order to add them in, recommendations - dos/don’ts/alternative suggestions. I’d plan only to add 2-3 fish at a time, every 2-3 weeks. (Though perhaps better to transfer all the tetras together / add all smaller shoaling fish like corys / cloud minnows together). I was thinking of starting by moving the tetra or adding the pearl gourami. Loaches I gather best after a month or so from when the first fish are in (since sensitive to a lot of water changes if there's a mini-cycle).

Many thanks,

Dan

 

[Essjay]

For any non-UK members, the tank is 33 American gallons.
And a Juwel Rio 125 is 81 cm wide x 36 cm deep x 50 cm tall (32 x 14 x 20 inches)


The trouble is that all the fish on your list are soft water fish. Since you live in London with its liquid rock coming out of the taps, you have 2 options. Either rethink your fish wish list and choose hard water fish, or use RO water in the tank instead of tap water; maybe mix 25% tap with 75% RO. If you haven't come across that term yet, RO stands for reverse osmosis. This is a process of forcing water through a membrane to remove everything dissolved in it. You can either buy it from a fish shop or buy the equipment to make your own.

If you were to go down the RO route, a few comments on your list.

Firstly, frogs should be kept in a species only tank. With fish they are likely to starve to death as they find their food by smell and by the time they've found it, the fish have eaten everything. They also need to breathe air, and in a tank like the Juwel Rio they would have a long way to swim to the surface (I used to have a Rio 125). Also, they are very sensitive to fish medications so if ever your fish got sick, you'd need to remove them. (Or move the glowlights and keep frogs in the smaller tank)

Pearl gouramis really need a tank 90 cm long. But provided you have only 1 male, you should be OK. Bear in mind that fish in shops are usually immature so a 'female' may well be a male that has yet to develop.

The bristlenose is the smallest commonly available plec; I would not go with anything bigger in your tank.

Cories are not bottom cleaners. They need to be fed their own sinking pellets. Get them if you like them but not for keeping the tank bottom clean as they can't live on left overs. You need a minimum of 6 with more being better.

Kuhli loaches don't eat snails to the best of my knowledge. And you'd need at least 6 of them.

Elephant noses need a 120 cm long tank, so it's not an option here.

Shoaling fish - it depends what you like


But please note - all these fish need soft water and if you don't want to use RO, it would be better if you considered hard water fish instead.

 

[nobo]

Many thanks for your incredibly helpful and detailed reply - much appreciated.

My guess/fear is that RO water may not be practical, so I may be back to the drawing board. That said, the hard water options I've come across so far (e.g. guppies, platties and dwarf rainbow fish) just aren't grabbing me in anything like the same way as any of these options. I'll do some research and have a think...

 

[Byron]

I would suggest you ascertain the GH of your source (tap) water and then test the aquarium water GH separately. I agree with what essjay posted, but the pH being below 7 suggests the parameters are being affected likely by the substrate material, and it is as well to pin this down on that basis alone, but you might find some compromise depending upon the numbers. Explore the options before giving in.

 

[nobo]

Thanks Byron,

As best as I can tell from my test strips:

Tap water: pH7.5, KH180 (though hard to read), GH is off the charts (over 180) - strip turns indigo/purple; scale tops out at blue 180. Thames Water for the postcode has:
Calcium carbonate(CaCO3): 256 ppm
Degrees Clarke:18
Degrees German(DH):14
Degrees French:26
Hydrogen Ion pH: 7.6

Big aquarium: (Been up for about 1 month - only snails; plants only in for about 4 days but readings pretty consistent): pH7, kH c.100, GH 180. It may be the substrate and/or driftwood has taken the edge off a bit.

Small aquarium: (glowlight tetras and amano shrimp and plants): pH 7.5, kH c.100, GH 180 (maybe more).

Given that I'll be sourcing fish locally (Tropical Marine Centre in Balham), is it possible that their soft water fish are already fairly acclimatised to London's hard water (or perhaps they're using RO?)? I'm guessing putting the sorts of species I've mentioned above in hard water isn't advisable...? The glowlight tetras (which I was given along with the tank and amanos by their former own) has always been in London's hard water (despite preferring soft) and (at least) appear happy... But then I'm far from expert!

 

[Byron]

I had thought the pH might be higher in the tap water, and the lowering to below 7 might be on the right track, but the tap pH is not that high (not as high as I would expect from such a high GH), so that doesn't seem very helpful. But there is some good news in this data. The tap water GH of 14 dG seems to be lowering to 10 dG in the aquarium, and that does open up some options in the fish species that may be "primarily" soft water species but that do seem to be OK in moderately hard water. This leads me to your question...

Given that I'll be sourcing fish locally (Tropical Marine Centre in Balham), is it possible that their soft water fish are already fairly acclimatised to London's hard water (or perhaps they're using RO?)? I'm guessing putting the sorts of species I've mentioned above in hard water is in advisable...? The glowlight tetras (which I was given along with the tank and amanos by their former own) has always been in London's hard water (despite preferring soft) and (at least) appear happy...

Freshwater fish species have each individually evolved over thousands of years to function in very specific water parameters (all aspects of their environment also factors in to this) and as soon as the parameters move away from the individual species' preferences (more like requirements) it causes trouble for the fish. There are (as always) some exceptions (which not surprisingly have obvious explanations), and also each individual species can be more stringently or less stringently tied to their preferences, but the science is clear that the fish will have less difficulty carrying out its life in water that is suited more closely to what is has been designed for, without exception.

The adaptability of fish to evolve over time is clearly real. But evolution takes time. We often are told to take "x" amount of time acclimating new fish to the tank, but the fact is that this alone takes weeks, sometimes months, but never hours. The fish in a store are meant to be there for a very short period before they are sold. Short-term manageability is a very different thing from expecting the fish to "adapt" long-term. Most cannot. If they do survive, and again depending upon the species, they are likely being impacted internally in ways we cannot see externally. They will usually be weakened in general, making them more susceptible to other issues like disease along the way. And they always have a shorter than normal lifespan. It is not scientifically proven what this may do to the fish; it is easy to ask a person how he/she feels about being denied this or that, or forced to do this or that...but asking a fish...? We can only learn what the fish species "expects" from its natural habitat, and provide that as close as possible. Given the results when this is done does make it clear that the fish can be healthy, more resistant to disease, and live a normal or longer lifespan, and that is probably the best indicator.

Fish that swim around and eat and reproduce does not mean they are healthy, and absolutely no aquarist can ever possibly know a fish is "happy" and "OK." Unless it is in the expected environment, be that nature or a well-furnished aquartium that provides for its expectations. Surviving and thriving are two very different things.

 

[nobo]

Thanks. I suspected (given the quotes in your signature) that might be the case.

So I guess the question is ... what fish should I be looking at for this tank?

(I'm kinda stuck with the glowlights in one or other of the tanks. Ssorry glowlights if you're not happy! I felt obliged to take them as the previous owner was threatening to chuck out the lot. But maybe a quick death is better than slow torture in hard water...?!?)

 

[seangee]

What @essjay and @Byron say is spot on. I live in Thames valley so my water is similar to yours. For many years I believed that tropical fish only lived for 1-2 years, and of course the local store was more than happy to sell me replacements every single year. I tried various methods of softening the water and ended up going for pure RO water. When the store tells you the fish have been acclimatised (or hardened as they say in my local store) what they mean is they dump live caught fish into rock hard water. Any that haven't died after about 10 days are "hardened" and this is what they sell.

Now as for the species you mentioned (assuming soft water) it is best to resist the temptation to go for a big variety. All the species you mention to much better in larger groups - my smallest group of any of these species is 15 (except otos because even my biggest tank could not provide enough food to feed them).

Since you already have glowlights stick with these. Pencilfish would work well with these - but I would suggest n.marginatus as they are better community citizens . And then a single species of corydoras, its your choice. Probably about 10-12 of each for this size tank. Corys do need a sand substrate and all of these are soft water fish.

 

[Byron]

Thanks. I suspected (given the quotes in your signature) that might be the case.

So I guess the question is ... what fish should I be looking at for this tank?

(I'm kinda stuck with the glowlights in one or other of the tanks. Ssorry glowlights if you're not happy! I felt obliged to take them as the previous owner was threatening to chuck out the lot. But maybe a quick death is better than slow torture in hard water...?!?)

Given that we are now at 10 dGH, I would not worry about the glowlights. I will post some species that from the perspective of water params I would consider if this were me, which will include any species from post #1 that could work now. And i am keeping in mind the tank dimensions essjay posted in #2, just so you know.

White cloud mountain minnows [these are best with cooler rather than warmer temperatures, so room temp (say around 70F/21C) would be better. Some of the following are OK with this, or perhaps a degree or two higher, while other would need it warmer (higher 70'sF/25-26C).

Pearl Gourami (this needs the upper temp and no good with fast swimming shoaling fish like the white clouds anyway) in a trio (one male, two females). Glowlights OK here.

Harlequin Rasbora Trigonostigma heteromorpha (nice match with the gourami), shoaling so 7-9. The two smaller species in the genus are possibles if you can keep the GH no higher than 10 and the pH below 7.

Corydoras, in a group of 7-10. Species like C. paleatus, C. aeneus, C. panda, or C. sterbai should be OK here. All one species, or mix (aim for 3-5 of each species if combo). Kuhlii I wouldn't given their digging with this substrate, cories should be OK if you have 2 inches of sand over the other, but they might get that all mixed up in time.

Rainbowfish, there are some species suited to this water. Pencilfish are better with much softer water; though Nannostomus beckfordi would work but caution: this is a feisty fish and will nip any other fish that enters its space (the top third of the tank) so not with gouramis. I've seen this fish give otos a very rough time for this.

Pristella maxillaris Pristella Tetra.
Hemigrammus ocellifer Head & Tail Light Tetra
Thayeria boehlkei Penguin Tetra, interesting as it swims at an oblique angle near the surface.
Hyphessobrycon flammeus Flame Tetra
Hyphessobrycon megalopterus Black Phantom Tetra

The last five are shoaling, a group of 7-9 of whichever, obviously not all of the above together. But example, two or three of the shoaling (depending which), plus cories, plus Pearls. Or 4-5 of the shoaling (including cories).

 

[utahfish]

Saw that you mentioned a bristlenose plec because they stay small. They average about 5 to 6 inches but the also commonly available clown pleco is smaller at around 3 inches.
Having said that most plecos dont eat a ton of algae are messy and need wood to lunch on.

 

[nobo]

Thanks all for your help.

As with every aspect of this hobby (er, and life!), I feel like every time I have a question (or think I have an answer), I’m really just on the edge of an infinitely deep rabbit hole! The challenge will be trying to find an acceptable level of education (in relatively limited free time) so as not to stress the fish … without my disappearing into the internet forever!

As my tap water is DH14 and I’m not entirely trustworthy of my reading of my API strips/there are possibly other factors that may mean the DH is not consistently lowered from that point (initial effect of substrate/driftwood) may have brought this down, but it might creep back up over time (?), my guess is this would be the prudent figure to use when it comes to choosing fish (?).

Unless perhaps I go with a rechargeable water softner pillows? (e.g.https://www.amazon.co.uk/gp/product/B002DW0GQQ/?tag=) Or is this just a gimmick that won’t reliably work/another rod for my back/will lead to erratic water quality?

On that basis, it seems I should be good with pearl gouramis (max 30dH), bronze corys (20dH), bristlenose or clown pleco (both 20dH) and various other fish that are happy at c. 25’C. [Source: http://www.wetwebmedia.com/FWSubWebIndex/HardWatrCommTkStkMonks.htm, which lists a lot of fish apparently suited to hard water]

Elephant nose and frogs appear to be definitely out! White cloud mountain minnows (prefer lower temps) and pencilfish (prefer softer water) too.

The issue with corys, loaches (yoyo or horseface seem ok in hard water, though latter probably too big) and plecos appears to be substrate. I have about an inch of sand over the soil. I might be able to increase that a bit, but at 1 – 1.5” it seems these fish would risk mixing all the soil and sand up… Maybe I just need to add 10kg (c. 1”) of sand…! But then I don't really want them to munch through my driftwood! (Or are we talking negligable nibbling?)

 

[Essjay]

Those water softening pillows, although made for aquariums, should not be used. The instructions say they should be recharged in salt water which means all they are doing is swapping the hard water minerals (calcium & magnesium) for sodium. No soft water fish have evolved to cope with a lot of sodium in the water.
There is a thread about Pozzani hardness filters, you will notice that although they reduce GH, they don't really affect KH (carbonate hardness) and pH drops slightly. Again the downside is the cost of replacing them as they wear out.

Hardness: does this make sense

While on the Pozzani site to re-order nitrate reduction cartriges I spotted this https://www.pozzani.co.uk/product_info.php?products_id=184. I bought a cartridge to try since I am already filtering my tap water so its no additional effore or time.. Tonight I did my usual 100 litre change (180...

www.fishforums.net

With a Rio 125, you could maybe have dwarf chain loaches, Ambastaia sidthimunki. They don't dig, but you couldn't have any other bottom dwellers with them. But..... you would need a shoal of them and they are not cheap!
I've only ever kept pygmy cories and at their size they don't dig very deeply.
I've not kept bristlenose plecs so I can say from experience if they dig or not.


But if you do decide that it is too much trouble/expense altering the hardness, there are lots of hard water fish to consider.
Rift Lake cichlids
Livebearers - and there are more than just guppies, platies, swordtails and mollies
Rainbowfish
Some species of killifish

And I'm sure other members can add to the list.

 

[Guppy10]

Agree with the above, avoid frogs, messy creatures.
I love my green barbs, so entertaining , angels are magnificent, plus gourami are graceful

 

[nobo]

Thanks all. I think softening the water is going to be too much hassle, so will investigate options good in harder water. Seems like I'm still on with pearl gouramis, at least

Will look into the others and come back with revised proposals when I've researched (including the helpful suggestions above) and found some that take my fancy. Comments/suggestions of course welcome in the interim!

 

[Essjay]

The thing that confuses me is why is your tap water 14 dH but your tank water 10dH? Hardness doesn't usually go down in a tank (though it can go up if there is a rock or substrate made of calcium carbonate). I would be concerned that whatever is lowering GH might only be temporary and you'd find the tank GH creeping up again.

Since you are using test strips, one thing you could do is take some tank water and some tap water to a fish shop that used liquid reagents to test for GH and see what they make of them. Or buy a GH liquid GH tester though that is even more expense.