Adopting a stocked tank!

[IndiaHawker]

Hi, this is my first post here, plan to introduce myself properly in the introductions thread when I get chance later! For now, I'm just looking for some advice on this please.

I'm taking on a Fluval Flex 57L tank which includes about eight small fish (can't remember the species off the top of my head, if I remember correctly from past experience most/all of the fish are types that stay small! There is also a pleco/loach included (looks like a bristlenose but without the bristles - maybe because female or juvenile?) I think a bristlenose could outgrow the tank? But I guess a good excuse to invest in a larger tank a few years down the line if needed

I have done a lot of research on fishkeeping in the past, both tropical and saltwater, but have never actually kept my own (had them as a kid but tended to mostly by my mum). And I'm a bit rusty on my research as this has suddenly sprung up and I'm getting a tank on Monday!

So far I intend to add a substrate to the tank beneath the current small pebbles, I'd like to plant up the tank naturally, although there are one or two real plants in it they haven't really rooted in due to nothing beneath the pebbles. It's coming with all the equipment I need to maintain it so I don't need to worry about that. If anyone can offer me any suggestions/advice decoration or maintenance-wise - or with anything - I'd really appreciate it!

Last thing - will I be able to add a few more fish if I like? Or should I keep it as it is for the sake of the fish? It did have a lot more fish in it which I thought was overstocked based on what I've heard/read in the past - but it was set up by a well-known company as a school project for many schools to participate in so I was assuming it's okay?

Any help really appreciated! Please and thank you in advance

 

[IndiaHawker]

EDIT: The tank contains approximately: 1x Red Wagtail Platy, 2x Zebra Danio, 4x Harlequin Rasbora, and an unspecified but possibly Bristlenose Plec!

 

[Byron]

Welcome to TFF.

First responding to the fish species and numbers included...danios and rasbora, like tetras and barbs, are shoaling fish that must have a group, six being the usual minimum but if space allows more will always be better for the fish (and usually the aquarist who will see more natural behaviours and healthier fish). Now, recognizing this was a rescued tank with fish, one has to realize that the fish may not be very young and sometimes it is best to leave them even if insufficient in number. But shoaling species that are less than minimum will inevitably be under stress (individual fish again can vary somewhat) which weakens their immune system and often increases aggressive tendencies.

But, if you intended adding to any of these, the tank is not sufficient room. Danios for instance are very active swimmers and need much more space (at least a 30-inch long tank). Rasbora are much less active, almost sedate by comparison, and a group of 7-8 of this species could be OK in this tank but I would first remove the danios. The platy are too big for this tank regardless, so again removing them would be best but depending upon the age factor...leaving all these fish as they are might be OK and kinder. But please do not add any new fish until the above issues are resolved.

You idea to re-aquascape sounds very good. The rasbora would love such a tank, on their own. With maybe the plec depending what it turns out to be...some get over 18 inches. Bristlenose are no more than 3-4 inches.

 

[IndiaHawker]

Hi, thanks for your help! As the situation stands it's not really an option to remove the fish as I have nowhere else to put them - I know the fish were bought likely nearly a year ago, originally in slightly bigger shoals but I don't think some survived - I think the school project idea is great to teach kids, but the humane side does worry me. I'm very much working with what I've got for now as like I said this was unexpected - however the first thing I intend to do is monitor the fish for signs of stress/aggression and go from there - if I need to get a few more fish for their shoals to help this then I will.

As there is only one Platy I thought that would be alright, I read that they grow to just over 2 inches and I'm bearing in mind the stocking 'rule of thumb' of one inch per gallon, and intending to stay a fair bit under it for good measure. As I mentioned, I'm aware of the potential size of the plec/loach and willing to work with that when it comes to it.

One of my first priorities is a couple more real plants to make the fish feel more comfortable and to help oxygenate the water. Also one or two decorations which provide hiding places. I intend to save as much of the current tank water as I can through the journey as I obviously can't cycle the tank beforehand but considering it's not a large tank I'm hoping this shouldn't prove too difficult.

Somewhere down the line I would like to get a couple more tankmates - but only once the current inhabitants are comfortable. I'd love a couple of small shrimp such as cherry shrimp (read that they like to be in groups but do they need to be in large groups or is just a couple okay?), or maybe just one siamese fighting fish if they're compatible. As you can likely tell I haven't done much research into this specific setup yet as only found out I was getting it today - but that's what I'm trying to do now. Please don't think I'm someone who will just go out and buy fish for the fun of it without thinking!

 

[Byron]

My earlier post was pointing out what these various fish require to be healthy and less stressed, and I did mention that as they have been existing it might be best to leave well enough alone and let them die naturally rather than not. Introducing new fish to a couple now does not always work, though it depends upon the species. But there is no room here for any of this regardless.

There really is no room for any more fish, and this could upset the applecart even if there was space. Definitely no Siamese Fighting Fish--male Bettas are not community fish. A Betta introduced here would be cruelty to the other fish (still don't know the tetra species but some will inflame a Betta, and check another current thread where a Betta introduced went wild over the platy and they are now shivering for fear in the corner. And small fish like tetra find Betta fins fun to nip, so there can be trouble both ways.

Shrimp I cannot speak for, but from bioload that is not a problem. They may get eaten, as crustaceans are natural food of most tropical fish.

As for the move, tank water is not useful except in cases where parameters of local water are significantly different. Without the parameters of tank and new source water, can't offer more. Keep the filter wet (carry it in a bucket of tank water) and all décor from the tank the same, this will preserve a lot of bacteria. If you can do what I suggest below, leave the substrate; if not, empty it into a bucket too and keep it wet. Fish with plants in buckets/tubs of tank water, cover them, fish will invariably jump from buckets if startled.

Empty the tank of everything before moving it, otherwise the weight can break the seal somewhere. However, an exception as this is just a 15g tank. Drain all water and remove most of the décor and plants. Keep the substrate in the tank wet. IF you can get the tank to slide onto a strong piece of plywood or particle board and you have two to carry it, this can work with smallish tanks. The aim is to put no pressure on the tank frame. Sitting on a thick piece of plywood usually achieves this, and you lift and carry the plywood obviously.

 

[IndiaHawker]

This is all helpful, thank you! One question: by leave the substrate, do you mean leave it in the tank, not leave it and replace it entirely? I'm assuming you mean the former but wanted to make extra sure.

As I'm thinking of getting something like Tetra Complete Substrate to put beneath the existing small pebbles, to root my plants into, I was thinking it would be best to get that before I get the tank - so during the moving of the tank I could add the new substrate then and there, instead of having to disturb the fish again later. Do you think this is the best idea, or that I'd be better off letting them re-acclimatize first, even if it means disturbing them at a later date?

Getting more worried about the amount of fish in the tank as I looked again today and it actually has: 6x harlequin rasbora, 4x zebra danio, 1x red wagtail platy, and the plec/loach (s/he is currently about 2/3 inches). According to the inch/gallon rule I could have another inch or two in there but obviously that's only if it's correct and I know it's only a rough guide anyway. And as you're saying, I have to account for the different species of fish themselves.

I have no plans to get more fish any time soon anyway. My main priority is to get the tank actually looking like a nice living space. Am I allowed to ask for website recommendations on here as to where I can buy some lovely live plants and natural decor (as opposed to the plastic 'real' stuff)? I'd love to get a small piece of driftwood for decor (and because I think I've read that plecs/loaches like/need it?) but I feel like I've read stuff in the past about how it can really affect the water quality so maybe it's best to leave that idea for now?

Sorry for all the questions and thanks for bearing with me! Thanks to anyone that helps

 

[Byron]

One question: by leave the substrate, do you mean leave it in the tank, not leave it and replace it entirely? I'm assuming you mean the former but wanted to make extra sure.

If you manage to move the tank as I described (the plywood) then yes, leave the substrate after you drain the water down to it. Don't have water sloshing about, that can break the seal too, but a damp substrate left alone will be best.

As I'm thinking of getting something like Tetra Complete Substrate to put beneath the existing small pebbles, to root my plants into, I was thinking it would be best to get that before I get the tank - so during the moving of the tank I could add the new substrate then and there, instead of having to disturb the fish again later. Do you think this is the best idea, or that I'd be better off letting them re-acclimatize first, even if it means disturbing them at a later date?

I am not a fan of these so-called plant substrates. Most are minimally useful at best, some totally useless. No idea what the Tetra is like, but I wouldn't waste the money. All my heavily-planted tanks have plain play sand substrates.

Plants will also grow well in gravel, if it is more fine than coarse; what is called pea gravel is as large a grain as you want, and some plants will find this a bit difficult. It can be beautiful in river tanks, with fewer substrate-rooted plants perhaps. Depends what you intend this tank "looking like" when finished; fish should determine the substrate. Some, like cories, should (well, must really) have sand. Play sand is ideal. But you might want to just leave what is there now for a time to get the fish settled. If you do change substrate, now or later, you need a temporary home for the fish, and another tank with the filter moved over is best. I've done this many times.

I have no plans to get more fish any time soon anyway. My main priority is to get the tank actually looking like a nice living space. Am I allowed to ask for website recommendations on here as to where I can buy some lovely live plants and natural decor (as opposed to the plastic 'real' stuff)? I'd love to get a small piece of driftwood for decor (and because I think I've read that plecs/loaches like/need it?) but I feel like I've read stuff in the past about how it can really affect the water quality so maybe it's best to leave that idea for now?

You should not add any more fish for a few weeks. During that time, decide what you want, some may have to go. There is certainly no space for any more as is.

Yes on plant websites; I've never used them so can't help there, but others will.

Most fish need wood in the tank. Loaches definitely, and chunks with crevices and tunnels are best. I have loads of Malaysian Driftwood in my tanks. Anything organic will affect water chemistry obviously, but without knowing the initial GH and KH and pH of the source water, this is difficult to predict. It is not "bad" just something one needs to know. A chunk of wood is not likely to make much difference; a tank full of dried leaves might, depending on the GH and KH.

 

[IndiaHawker]

Thanks so much for the help! Are plecos the same as loaches in regards to needing wood? I've purchased a few items online in anticipation of my tank:

https/www.ebay.co.uk/itm/RED-MOOR-AQUARIUM-WOOD-ROOT-SIZE-M-20-30cm-AQUASCAPING-BOGWOOD-DRIFTWOOD/173321108381?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I will soak this beforehand to make sure it sinks/help remove tannins. Will likely remove the included plastic stump ornament when I put this in.

https/www.ebay.co.uk/itm/Natural-Golden-Aquarium-Sand-Substrate-With-FREE-DELIVERY/232194852236?ssPageName=STRK:MEBIDX:IT&var=531406320116&_trksid=p2057872.m2749.l2649

This is to go beneath the included small pebble substrate to help the plants to root in well.

https://www.decathlon.co.uk/line-4x...mkCljXyDLtqfUW_hc2tzuZv1fw2NtLlhoCcLQQAvD_BwE

This is to tie plants onto the wood and any future natural decor.

https://www.pond-planet.co.uk/aquar...re-parts-c100/flex-filter-intake-screen-p2747

Because I read that small fish can escape into thee back of this tank without this. I bought two just in case there was more than one filter intake that needed covering.

https://www.amazon.co.uk/gp/product/B077HN9TPG/?tag=

Because my current adapter/adapter combo is dodgy, likely out of date, and doesn't have enough sockets.

https://java-plants.com/individual-plants/anubia-nana?___SID=U

https://java-plants.com/individual-plants/java-moss

https://java-plants.com/individual-plants/rotala-macranda

https://java-plants.com/individual-plants/vallis-corkscrew-large

https://java-plants.com/individual-plants/ambulia-aquatica

(most of the plants I bought potted)

This is what I've bought (and maxed out my budget on!) for my tank. What do people think?

 

[Byron]

Are plecos the same as loaches in regards to needing wood?

Most substrate fish like having chunks of wood around; it is in most cases very natural to their habitat. The "need" varies; some plecos need real wood to graze because it is essential to a healthy digestive tract. Loaches tend to only need wood, or something that provides the same thing, as places with tunnels and crevices for hiding, playing, sleeping.

 

[IndiaHawker]

Thank you!

I'm now having a new crisis - I've realised there is also a Bronze Cory still in there. I was really pleased to see him and think he's lovely - however he's on his own and I read that they like to be in shoals. There used to be one or two others with him but they clearly didn't survive. I'm debating getting just one more Bronze Cory so he has a tankmate - I read that they like shoals of 4/5+, but from my memories of my mum having a tank when I was younger, two or three seemed perfectly content together (although as a kid I admit my judgement might not have been the best). There also used to be three Honey Gourami in the tank, as well as possibly one more Zebra Danio, and a few more Red Wagtail Platy - this was a school project set up by a fish company so I assumed it was okay despite feeling like there were too many fish in there. So yeah, I don't know what to do...

 

[Byron]

I have already explained why this tank was never adequate for most all of the fish they had in it. That is not your fault in the least, but the point has to be made that this was never a good aquarium for these fish. Whoever set it up or advised on setting it up did not have a clue about fish requirements beyond the fact they need water.

As fort the lone cory, this is not good either. A group of five is minimum, according to the advice of ichthyologists who have studied this family. However, we have a small tank with too many fish species and insufficient numbers of most of the species (except the one platy) so adding any more fish is risky to say the least. [Obviously the best option would be a larger tank, or somehow re-homing some of the fish.] You can add four more cories (same species preferable) with very strict feeding and increased volume water changes, and floating plants. I could easily manage this, but I am always reluctant to suggest things like this unless I know the knowledge level of the individual; there are signs we can read that take some experience to recognize.

 

[IndiaHawker]

Thank you again, I really appreciate your knowledgeable and honest replies. The worrying thing is that this project is set up by a well-known fish company (at least in this area) for many schools, and the fish that are stocked in it are chosen by the company who set up the project itself (except for the loach/pleco, think that may have been added, but the only one that wasn't included in the project). Trust me I wish a larger tank was an option right now - in the future I dream of having something 200L+, ideally something huge, to set up a wonderful ethical environment with some truly spectacular fish... for now, a girl can dream!

I'd be willing to add four more cories if I believe I can maintain it - as for my knowledge level it's tricky - for someone who hasn't owned my own tank before (as in, maintained it by myself) I think I have a pretty good level of knowledge due to years and years of on and off obsessive research - however compared to experts and people who own tanks themselves and have successfully done so for a while, I'm obviously lacking in knowledge. I've listed the plants I've bought and to my understanding, real plants help with the oxygenation of the tank, and possibly with the water quality although not 100% on the latter? I haven't ordered any floating plants but am totally willing to do so if it would enable me to significantly improve the life of my poor lovely lonely Cory. I'm also trying to provide as many hiding places as possible to break the tank up and allow shyer fish somewhere to go and feel comfortable, without taking up more volume in the tank than necessary and further decreasing the capacity.

My backup plan is that I have another small tank. It would need a thorough cleaning as its last inhabitant died (a lovely Bristlenose Pleco) - although I believe this was due to my mum changing his environment too quickly, I would rather be safe. However this tank is smaller, and taller than it is wide, so obviously not ideal for oxygen levels. Plus like I mentioned I'm really lacking in space and don't know if I'd be able to make room for it anyway. This would be a last resort (or quarantine/fry tank if I ever need it), as I'd much rather keep the fish in the current tank and take adequate measures to make sure the fish can all be happy. One more question - when you're talking about the stocking levels of this particular setup, is it reaching its limits because of things such as possible oxygen and water quality levels, or because of sheer space for the fish to comfortably move around? Or a combination of both? I'm guessing the Cories wouldn't be as intrusive as other fish considering they mostly stay on the bottom, is that why I'd be able to house a few more if I can maintain the tank well enough to do so?

Thanks again for all your help

 

[seangee]

Corys do need a sand substrate.
The good news is the Flex 57 is really easy to maintain. Make sure you have plenty of plants. My water change routine is:

1. Wipe inside walls with a clean fish only sponge
2. Manual gravel vac into 2 x 15 litre buckets (I don't fill these so only end up changing around 25l of water)
3. Rinse filter media in these buckets before getting rid of the water
4. Add de-chlorinated water into the chamber where the pump is (chamber 3). That way you can do it quickly and not worry about disturbing the substrate or fish.

The whole process takes 10 - 15 minutes. Once a month I take a bit longer when I clean the pump and pipes.

The supplied filtartion system is perfectly adequate. If you are going to be overstocked you don't need a bigger / better filter - you need more frequent water changes, lots of plants help in this regard too.

The lights are perfectly adequate for easy maintenance plants. If you haven't already discovered this they will work with a timer but you have to turn them to white only and max power - otherwise when they come on you will get strange results.

Plants in this tank are water sprite (planted and floating), Vallisneria (v.spiralis) and there is also plenty of floating duckweed. (intentionally not mentioning the grassy stuff because I am struggling to get that to grow )

 

[IndiaHawker]

Corys do need a sand substrate.
The good news is the Flex 57 is really easy to maintain. Make sure you have plenty of plants. My water change routine is:

1. Wipe inside walls with a clean fish only sponge
2. Manual gravel vac into 2 x 15 litre buckets (I don't fill these so only end up changing around 25l of water)
3. Rinse filter media in these buckets before getting rid of the water
4. Add de-chlorinated water into the chamber where the pump is (chamber 3). That way you can do it quickly and not worry about disturbing the substrate or fish.

The whole process takes 10 - 15 minutes. Once a month I take a bit longer when I clean the pump and pipes.

The supplied filtartion system is perfectly adequate. If you are going to be overstocked you don't need a bigger / better filter - you need more frequent water changes, lots of plants help in this regard too.

The lights are perfectly adequate for easy maintenance plants. If you haven't already discovered this they will work with a timer but you have to turn them to white only and max power - otherwise when they come on you will get strange results.

Plants in this tank are water sprite (planted and floating), Vallisneria (v.spiralis) and there is also plenty of floating duckweed. (intentionally not mentioning the grassy stuff because I am struggling to get that to grow )

Nice setup! Love the natural look you've gone for, a similar style as to what I'm going for so good to see how you've done it! I do like the grassy stuff so far, hope you get it growing well soon

Definitely planning on having plenty of plants, as you can see I've ordered a fair few already to go with the couple currently in there. Didn't know that Cories required a specifically sand substrate, I'd read that either sand or a smooth gravel is good? I've ordered sand anyway to put beneath the current substrate (little smooth pebbles) to help root the sand in - why is it that Cories need specifically sand? Is it because they like to dig and the small pebbles wouldn't allow it to do so? Or do you just mean sand as opposed to something coarse that could harm its scales/barbels? I can work with this anyway as like I said I've ordered the sand and it's due to come this week!

A couple of newbie questions - I hope I don't sound too thick, I'm just trying to make sure I get everything right as getting tank tomorrow.

1. What do you mean by 'manual gravel vac'? I believe the tank is coming with some sort of gravel vac instrument although I may be mistaken, but honestly I've never used one before. Even if it doesn't come with one, I have no problem with sieving the pebbles and rinsing them in dechlorinated water once a week if that's what you mean?

2. With this amount of fish, is a weekly partial water change enough, or will I need to do it more? Once again, willing to work with whatever, just want the fish to be happy. The tank does come with some water testing stuff, so at least I can keep a close eye on the water quality.

Thanks for the info about the timer, good to know! I have no imminent plans on getting a timer as it shouldn't be a problem to turn it on and off at the right times, however good to know as I may invest in one in future! Could be handy. I likely plan to keep the lights at least mostly on white - I love the light options but worried about stressing out the fish by changing the light colour regularly - how do you find this?

Plan on getting at least one floating plant then - do they help the oxygenation levels a lot compared to planted alone? Never owned floating plants but could be interesting!

I'll try and post a photo of my tank soon - before and after I've got my hands on it Hope you don't mind me asking your advice with the tank in future as it could be helpful speaking to someone with the same tank!

Thanks for the help!

 

[Byron]

Didn't know that Cories required a specifically sand substrate, I'd read that either sand or a smooth gravel is good? I've ordered sand anyway to put beneath the current substrate (little smooth pebbles) to help root the sand in - why is it that Cories need specifically sand? Is it because they like to dig and the small pebbles wouldn't allow it to do so? Or do you just mean sand as opposed to something coarse that could harm its scales/barbels? I can work with this anyway as like I said I've ordered the sand and it's due to come this week!

All species of cory with one or at most two exceptions live over a substrate of either sand or mud, often but not always with leaf litter (dead leaves). This is important, because the cory naturally digs into the substrate and takes up a mouthful and sifts it out through the gill slits, looking for tidbits of food. Obviously this is not possible with gravel unless it is very fine and the cories large. While they willnot obviously die over fine gravel that is not rough, thye will be in better shape over sand that is not rough. Never use any industrial sand like blasting for this reason.

This is one of those things you need to decide; if you intend more cories, it wold be best to remove the gravel and have just sand.

Sand will naturally sink to the bottom when mixed with any larger-grain sand or gravel.

1. What do you mean by 'manual gravel vac'? I believe the tank is coming with some sort of gravel vac instrument although I may be mistaken, but honestly I've never used one before. Even if it doesn't come with one, I have no problem with sieving the pebbles and rinsing them in dechlorinated water once a week if that's what you mean?

This is one manual gravel cleaning water changing device (see photo). Pushing the large end into the substrate just a bit will loosen detritus and it gets sucked up with the water flow, out into a bucket. Don't remove the substrate, that is too stressful on fish. Clean open areas, don't worry about under rock or wood or around plants, those areas are best left alone.

2. With this amount of fish, is a weekly partial water change enough, or will I need to do it more? Once again, willing to work with whatever, just want the fish to be happy. The tank does come with some water testing stuff, so at least I can keep a close eye on the water quality.

A partial water change should be done every week at minimum (more frequently is not needed unless to help with some problem) on the same day as this will establish more stable water chemistry. I recommend 50% of the tank volume but more is fine, assuming the parameters of tap and tank water are close (GH, pH, temperature). Water changes are a regular factor in a biologically healthy and balanced aquarium, not something to be done if tests indicate trouble, though if they do, more changes usually help. So monitoring pH and nitrate is good, at least for a time until you see stability then periodically, and ammonia and nitrite once the tank is cycled and become established (a few months) should not be necessary unless fish die. Tests are usually the first step in such situations, then a major water change, then treatment if determined necessary.

Plan on getting at least one floating plant then - do they help the oxygenation levels a lot compared to planted alone? Never owned floating plants but could be interesting!

Plants that are faster growing will remove a lot of ammonia, CO2 and other nutrients from organics in the substrate. Floating plants are ideal for this as they are pretty well the fastest growing plants, and they provide shade which fish appreciate (bright light is not good for most aquarium fish). These will deal with the initial cycling too, especially here where you are getting an existing aquarium.

Plants respirate same as fish and many bacteria...taking in oxygen and expelling CO2. This is continuous so long as the plants are alive. During the day they use CO2 to photosynthesize, producing oxygen as a by-product. During darkness, they revert back to normal respiration. This can cause a lessening of oxygen and increase of CO2, which is normal and not a problem as it is one way CO2 builds up for the next period of light, but if there are a lot of plants and fish this can cause issues. Surface disturbance should avoid this problem. Fish respiration rates in the early morning just after the light comes on can guide you with this; rapid respiration may mean you need more surface disturbance during the night.