Going Tropical From Goldfish, Advice Needed.

[PeteStewardson]

Hi,

Just joined up to get some more info and advice about moving from the current goldfish to some tropicals in our tank.

Background is we moved into a new house where the previous owners had koi carp and a massively deep pond. We have a toddler so filled the pond in, but when draining the pond we managed to adopt 4 goldfish. These rapidly grew and two died ( I think due to the tank being too small for 4 large goldfish ) but the others have lived on and are healthy. But one is 6" and the other is 5" and so they're again too big for the tank we have. I'll be sad to see them go because they're so friendly and beg for their food at exactly the same times each day etc but it's not good to keep them. So I'm trying to re-home those and go for some tropical fish. I'm asked in the local shop Maidenhead aquatics in winnersh but they said they wouldn't take them.

So I have a 160l tank and fluval 405 external filter. The tank has gravel in it and a couple of plants but not too much else. I do have a heater from when I bought the tank. I measured the tank yesterday to work out the water volume after plants and sand etc and the water level and it came to 130l

I'm thinking of doing a weekend swap to avoid cycling from scratch. So re-home the goldfish, then swap the gravel for some playsand and plant some more plants in there. Then leave it overnight for the sand to settle and go and buy some tropicals. I'm assuming that if I leave the tank running then the bacteria in the filter wont die so quickly which means I will have a pre-cycled tank.

I'm not 100% sure what I can stock in the tank though. I was thinking something along the lines of -

4 Dalmation Mollys, 4 Black Mollys, 4 Red Wagtail Platys, a Bulldog Plec and some Polkadot Loaches, maybe some Cardinal Tetras to add some colour.

Does that seem sensible and are they all compatible? Anything they need specifically in the tank etc? I've read that the Bulldog Plec needs wood to sit on and eat. I'm guessing the 405 filter will need to be turned down a bit as well as it's a big filter for a 160l tank.

Any help and advice would be appreciated. Especially on how best to stock the tank as I'm assuming buying everything in one go would be crazy even for a cycled tank.

Pete

 

[justin85]

Hi pete,

Welcome to the forum.

Moving from cold water to tropical couldn’t be easier! realistically its just warm water that makes it tropical, then you have specific’s for each species of fish i.e. PH, so firstly you will need that heater, for a 160L (130L after gravel/rock displacement) I would get at least a 150W heater. I will try and help the best I can, but im not expert.

I'm thinking of doing a weekend swap to avoid cycling from scratch. So re-home the goldfish, then swap the gravel for some playsand and plant some more plants in there. Then leave it overnight for the sand to settle and go and buy some tropicals. I'm assuming that if I leave the tank running then the bacteria in the filter wont die so quickly which means I will have a pre-cycled tank.

The bacteria in the filter will be fine as long as it’s left on, it can also survive when turned off for a short while adding an air stone/air pump will give you more time. The gravel will be home to a colony of bacteria also, so keep that in mind when you remove it.
After you adding the play sand it is going to cloud your water big time! Even if you rinse it loads before adding so adding fish right away might not be the best idea, it really depends on what you want.

I'm not 100% sure what I can stock in the tank though. I was thinking something along the lines of -

4 Dalmation Mollys, 4 Black Mollys, 4 Red Wagtail Platys, a Bulldog Plec and some Polkadot Loaches, maybe some Cardinal Tetras to add some colour.

Does that seem sensible and are they all compatible? Anything they need specifically in the tank etc? I've read that the Bulldog Plec needs wood to sit on and eat. I'm guessing the 405 filter will need to be turned down a bit as well as it's a big filter for a 160l tank.

I'm not 100% on all these fish you mentioned but I think there all peaceful and will do fine together, But be sure to check online for the individual profiles of each fish and you will find all the info you need, I do this before buying any fish just type the fishes name in to Google and it will come up with a profile on that fish. As for the filter, there is no need to turn it down mate, you can never have too much filtration!


Just make sure not to add too many fish at once or you could push the tank back in to a cycle and you could lose some fish. Picking the fish is really down to you and what you want in the tank, but like I said always check online first, most pet stores will tell you there fine and easy to keep just to make a sale keep this in mind when asking for advice from any pet shop.



Hope this helped.

 

[PeteStewardson]

Thanks for the comments. I'll check but I think the heater is a 150w one, I've never needed it with the goldfish.

I've been told the mollys like the water slightly slaty and so they might not be the best fish to keep with the rest. A friend into tropicals told me he'd not have Mollys and would get Corys's instead so might take his advice there.

I certainly wont be adding all the fish in one go, although I imaging I've got quite a healthy bacteria build up coping with 11" worth of messy goldfish

 

[justin85]

Thanks for the comments. I'll check but I think the heater is a 150w one, I've never needed it with the goldfish.

I've been told the mollys like the water slightly slaty and so they might not be the best fish to keep with the rest. A friend into tropicals told me he'd not have Mollys and would get Corys's instead so might take his advice there.

I certainly wont be adding all the fish in one go, although I imaging I've got quite a healthy bacteria build up coping with 11" worth of messy goldfish

Yes, you should have a good colony in the filter for sure. I’ve not kept Mollys so I can’t help there, Corys are very common and easy to keep so would be a good choice. If you have not got a water testing kit, I would suggest getting one so you can monitor your water conditions.

 

[PeteStewardson]

Yes I've got a testing kit, forget which make but it's a liquid kit that I bought to keep tabs on the tank originally.

 

[KittyKat]

What are the dimensions of the tank? The volume in itself does not matter much.

You are correct in wanting to switch to sand, that will be best for loaches and a bulldog pleco. I strongly recommend that you wash the sand very well, as it will take over a day for it to settle if there is any dust in it. You might also want to consider using a small bag of sharp sand with the play sand to break up the uniformity of the play sand if the play sand is the same throughout. Sharp sand is not actually "sharp", it just means that there are some larger bits of stones in it.

Do you know what your water hardness (GH and KH) and pH are? These will affect which fish are most compatible with your tank. For example, I advise against mixing hard water and soft water fish because it's not really much good for the one that the parameters are wrong for in the long term.

You are also correct in that if you do a straight swap, you do not need to cycle.

 

[PrairieSunflower]

This facebook page might offer you some help rehoming your goldfish, if you haven't already.
https/www.facebook.com/groups/424216964273600/

I belong to this group and its for advertising your fish free to good homes and there are a lot of members that rehome all sorts of fish in various areas.

 

[PeteStewardson]

The tank I've got is about 35"x15"x15"( water height if I take into account substrate etc )

I'd need to do a water test for the PH again but I remember it being high 7's when I tested it originally when we got the goldfish.

 

[KittyKat]

The tank I've got is about 35"x15"x15"( water height if I take into account substrate etc )

I'd need to do a water test for the PH again but I remember it being high 7's when I tested it originally when we got the goldfish.

That's a pretty standard sized tank, how deep do you plan to have your substrate? You're right that it is by far too small for goldfish, and it's great that you're finding them a bigger home.

Since I am more used to working in metric, that's 89*38*38 cm. In the grand scheme of things, it's not big, but we should be able to find you plenty of fish that will be happy in that.

Going back to your list…:
* 8 mollies - these can get up to around 6" (which is too large for the tank, really), depending on the hybrid/species (most often, these are hybrids); prefer hard water (see last paragraph in this link); keep at least 2 females per male
* 4 platys - ok for size, ok for number (I'd prefer to have at least 5); prefer hard water; keep at least 2 females per male
* 1 bulldog plec - if you mean Chaetostoma formosae, then okish; if you mean a larger species, then too large; I'd prefer to keep a smaller species and 2f 1m instead of just an individual
* 6+ polkadot loaches - must have a longer tank due to adult size, shoaling fish, so 10-15+ would be more ideal
* 6+ cardinal tetras - prefer soft water; schooling species, so 10-15+ would be ideal; ideally should have at least a 3 ft tank

Since you have just-over-neutral water, by the sound of things, based on your plans, I would recommend something along the lines of…
* 5 male platys (females will be affected by the not-hard water more than males, but personally, I would leave these out altogether)
* 1m 2f plecos of one species or 6+ otos of one species (examples, in order of popularity for research: Hypancistrus debilittera, Parotocinclus jumbo (best bet), any common Otocinclus sp.) - I would probably have Otos or loaches, not both
* 8-10+ Yasuhikotakia sidthimunki (dwarf chain loach) or 8-10+ Yunnanilus brevis or 10-15+ Yunnanilus cruciatus or 10-15+ Yunnanilus sp. 'rosy' (I have kept the latter and they're lovely little fish!) - loaches are very social animals, so really do need the larger groups
* 10+ rasboras of one species (for example, I would consider T. espei or T. hengeli to be ideal, or any other rasbora or peaceful barb that grows up to 4-5 cm)

If it were my tank, I'd stock with the following:
* 15 3-4cm rasboras (I would chose hengeli rasboras)
* 12+ loaches (I would chose Yunnanilus cruciatus)
* 1-3 pairs of peaceful gouramis (including Bettas) of one species (I would chose 3 pairs of Betta simplex)

I consider it quite important to keep fish in appropriate groups, so when stocking from scratch, I think that one should aim for "ideal" minimum numbers, not "absolute" minimum numbers. I realise that the list I give you contains more fish than you planed, but these are all smaller fish, so are a lighter bioload.

If you go for my ideal tank, then I would replace the two goldfish with 12-15 hengli rasboras, then add 6 and 6 loaches 2 and 4 weeks later, and finally 6 Bettas another two weeks later.

For acclimatisation, I strongly recommend that you drip acclimatise, as changes in water parameters can kill fish.

 

[PeteStewardson]

Thanks for the help so far.

Substrate wise I don't know how deep I should have it. I have about 2" of gravel in right now which the goldfish move around a lot. But that's not taking up any of the 15" of water depth I'm talking about as I've excluded that in my measurements.

 

[KittyKat]

I'm guessing the 405 filter will need to be turned down a bit as well as it's a big filter for a 160l tank.

To be honest, a 1300 lph (litre per hour) filter for a (technically) 160 litre tank is not horrendously fast after media, etc., and I would expect a spray bar aimed along the surface to be enough to slow down the flow to something quite reasonable.

Substrate wise I don't know how deep I should have it. I have about 2" of gravel in right now which the goldfish move around a lot. But that's not taking up any of the 15" of water depth I'm talking about as I've excluded that in my measurements.

I like to have 1-2+" at the front and 4-6+" at the back for plants. In a 2 ft tank, I even have it down to 1 cm right at the front because there's no border, but in a larger tank where I have plants against the front, I have it 3" deep at the front.

Regarding heaters, 1 watt per litre (when full to the brim) is what most people want in a tank that is in a room where the temperature never drops below 16 C. If the room gets colder, aim for more watts, but I would not aim for any less. Also, it is a bad idea to have too powerful a heater because heaters can break in the "on" position, which can result in fish being boiled alive (not fun). If you have loads of cash around, then it's always better to have two heaters, rather than one. So, in your tank, I would aim at a 150 W heater, or 2* 75 W heaters. If you go for a traditional glass heater, then Visitherm are the best that I've used. If you have more cash to spend, then a NeWatt is quite good because it is not glass. I do not feel any incentive to go for in-line heaters, because if the filter breaks, the heater stops working too (fish don't need everything going wrong at the same time!).

 

[PeteStewardson]

OK well I run a spray bar now on the back wall of the tank, but I have it just above the surface as the goldfish seemed to like the amount of air bubbles it introduced.

I've just checked and the heater I have is an Interpet Delta therm 300watt, it's the one I got when I bought the tank as a package deal from Maidenhead aquatics about 18months ago.