Stocking help

RobbiHask

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Hi all, I have a Tetra AquaArt Explorer 60L that's been running for about 6 months https://www.swelluk.com/tetra-aquaart-explorer-tropical-tank-60l/ prior to that I had a fluval chi 25L also running for about 6 months before I upgraded and kept the filter and decor before upgrading the filter about a month later.

It's currently stocked with 4 Cory's, 1 Guppy, 4 Amano shrimp and a few baby snails. I was looking at which fish I can add to the tank in the future.

The filter I'm using is an Interpet CF3 filter ( https://www.amazon.co.uk/gp/product/B00QGAIE88/?tag= ) with a maximum flow of 950L per hour, I've altered it to be a sponge filter with 3 levels of filtration and a bag of Biomedia in the middle. I'll also have to add some netting to the filter as I've seen that the tetras can get sucked in.

The tank's well planted, I've got a large banana plant at the back, a few Anubias (one of which is already touching the surface water) and some unknown plants that I got from my local LFS.

I've been advised elsewhere that getting 2 more cory's and about 10 tetras would do well in the tank, which is good because I was thinking of getting a shole of tetras. I was reluctant to buy more cory's as, although the tank size is suitable in terms of volume, the floor area isn't as big as I'd like but I was just looking for some solid advice/opinions.
 
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PheonixKingZ

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A 15 gallon tank is pushing it for 6 Cory's. Who suggested you get 10 tetras? Most tetra species need to have a lot more room to swim. What is your pH, KH, and GH?
 
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RobbiHask

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A 15 gallon tank is pushing it for 6 Cory's. Who suggested you get 10 tetras? Most tetra species need to have a lot more room to swim. What is your pH, KH, and GH?
Thanks for responding, the PH is around 7.6 using the API Master test.

It was a user over on an aquarium reddit forum, I have just tested the KH & GH using an API test and it took 14 drops for the KH to change and 17 for the GH - from what the instrutions are telling me this is ober 214.8 ppm so I'm gonna need to get on that...

Should've specified that it was neon tetras we were looking at if that makes a difference and using the calculator on here it gives me the following volumes;
Volume​
Water Weight​
Litres​
Imp. Gallons​
US Gallons​
86​
19​
23​
 
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seangee

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What type of corys do you have? This may be important because some of the pygmy corys do better in groups of 10+. You do have the space to accommodate these, and possibly more of the larger corys, but it does depend on the species.

The answer to the GH question may be significant. Of the fish you mention guppies require hard water and corys and tetras do better in soft water. The information should be available on your water supplier's website. We do need a number and the unit it is measured in.

The volume of the tank is fine for a group of neons, but the potential issue is the shape of the tank and whether they have enough swimming space. The usual recommendation for neons is a 60cm (2") tank. For a rectangular tank this gives them 60cm to swim across the entire depth of the tank. Your tank is only 51cms - but importantly that is only at the long edge. You may be better off considering a "nano" fish. Ember tetra (https://www.seriouslyfish.com/species/hyphessobrycon-amandae/) may be a better choice if your water is not too hard and you are set on tetras. If it is harder water you could consider something like celestial pearl danios (https://www.seriouslyfish.com/species/celestichthys-margaritatus/) with a bigger group of say 20.

But lets get the water parameters before making any decisions.
 
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RobbiHask

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What type of corys do you have? This may be important because some of the pygmy corys do better in groups of 10+. You do have the space to accommodate these, and possibly more of the larger corys, but it does depend on the species.

The answer to the GH question may be significant. Of the fish you mention guppies require hard water and corys and tetras do better in soft water. The information should be available on your water supplier's website. We do need a number and the unit it is measured in.

The volume of the tank is fine for a group of neons, but the potential issue is the shape of the tank and whether they have enough swimming space. The usual recommendation for neons is a 60cm (2") tank. For a rectangular tank this gives them 60cm to swim across the entire depth of the tank. Your tank is only 51cms - but importantly that is only at the long edge. You may be better off considering a "nano" fish. Ember tetra (https://www.seriouslyfish.com/species/hyphessobrycon-amandae/) may be a better choice if your water is not too hard and you are set on tetras. If it is harder water you could consider something like celestial pearl danios (https://www.seriouslyfish.com/species/celestichthys-margaritatus/) with a bigger group of say 20.

But lets get the water parameters before making any decisions.
I have just tested the KH & GH using an API test and it took 14 drops for the KH to change and 17 for the GH - from what the instrutions are telling me this is over 214.8 ppm - using a water hardness map is saying it's over 276ppm.

I have 2 peppered corys and 2 albino
 

essjay

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17 drops with the API tester = 17 dH and 304 ppm. That is hard water.

Tetras will not do well in water this hard, I'm afraid. And neither will the cories. The guppy is fine though.

The tank is an awkward shape being a semicircle with the back being 51 cm (20 inches)across, the height 51 cm (20 inches) and the front to back at the widest being 33 cm (13 inches).
The only fish I can think of that would be suitable in this hardness and tank shape is endlers. Males only.
Other members with hard water may be able to suggest other hard water fish that would be suitable for this tank.
 

seangee

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That is very hard. Have you considered endlers? https://www.seriouslyfish.com/species/poecilia-wingei/
Probably best to stick with males only. Besides the fact that they are better looking you don't have the space for fry when they breed. I would not add any more corys, they will have fairly short lives in this water. Let them live out their lives but don't add any more - at least that is what I would do.
 
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RobbiHask

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17 drops with the API tester = 17 dH and 304 ppm. That is hard water.

Tetras will not do well in water this hard, I'm afraid. And neither will the cories. The guppy is fine though.

The tank is an awkward shape being a semicircle with the back being 51 cm (20 inches)across, the height 51 cm (20 inches) and the front to back at the widest being 33 cm (13 inches).
The only fish I can think of that would be suitable in this hardness and tank shape is endlers. Males only.
Other members with hard water may be able to suggest other hard water fish that would be suitable for this tank.
That's a shame, although I didn't want to add more cories due to the size of the floor for them.

The cories have been in the tank for almost 6 months now and I haven't seen any issues, they've grown well and seem to be doing fine, is there anything I can do to make the tank suitable for Tetras / would they be find given suitable acclimation other than forking out for an RO system?
 

seangee

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You could mix your tap water 50/50 with RO which would make it OK for ember tetras and your corys. Last time I checked Maidenhead Aquatics were selling RO at £3.50 for 25 litres - ask for straight RO, you do not want it to be re-mineralised. For that sized tank I would change around 30 litres per week, which means 15 litres of RO every week.

My tap water is similar to yours. When I used it in a tank with corys and tetras my fish lived on average 12-24 months. I have switched to RO. Initially I used to buy it and mix 50/50 but ultimately I did buy my own unit and now use only RO. Most of the fish in the same tank now are over 5 years old and some are much older than that.
 

essjay

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would they be find given suitable acclimation
Soft water fish cannot acclimatise to water this hard, I'm afraid. They've evolved over thousands of years to live in soft water and we cannot overturn what is programmed into their DNA. Soft water fish retain most of the calcium in water because coming from soft water there isn't much so they need to hang on to what there is. Put them in hard water and they still retain calcium, so much that their internal organs become calcified and they die younger than they should.
 

PheonixKingZ

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I do agree that some endlers would be cool. Try to give your tetras and your cory cats away to your LFS. Or see if they would be willing to trade you some endlers for your fish.
 
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RobbiHask

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You could mix your tap water 50/50 with RO which would make it OK for ember tetras and your corys. Last time I checked Maidenhead Aquatics were selling RO at £3.50 for 25 litres - ask for straight RO, you do not want it to be re-mineralised. For that sized tank I would change around 30 litres per week, which means 15 litres of RO every week.

My tap water is similar to yours. When I used it in a tank with corys and tetras my fish lived on average 12-24 months. I have switched to RO. Initially I used to buy it and mix 50/50 but ultimately I did buy my own unit and now use only RO. Most of the fish in the same tank now are over 5 years old and some are much older than that.
Ok, thanks for the advice.

I don't think I'll be able to make the change to RO at the moment, a shame but I'll keep it in mind for future tanks.

When I started out I was painfully ignorant on how to keep fish and had some serious trial and error before I got to where I am, turns out I'm still learning as I only really focused on the parameters when setting this one up and didn't think about Hardness.

For now I think I'll find get some driftwood to try and lower it slightly and look at some hard water fish.
 
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RobbiHask

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I do agree that some endlers would be cool. Try to give your tetras and your cory cats away to your LFS. Or see if they would be willing to trade you some endlers for your fish.
Luckily I don't have the tetras yet, the corys came from a local LFS with the same water hardness that I use and as I've had them for about half a year I think they're doing OK in my tank, I'm always learning so all the responses are things I'll remember in the future.
 

PheonixKingZ

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Oh, ok. Thats a good thing you don't have the tetra yet. Did we identify what type of cory you have? If we did, I must have missed it...
 

seangee

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Ok, thanks for the advice.

I don't think I'll be able to make the change to RO at the moment, a shame but I'll keep it in mind for future tanks.

When I started out I was painfully ignorant on how to keep fish and had some serious trial and error before I got to where I am, turns out I'm still learning as I only really focused on the parameters when setting this one up and didn't think about Hardness.

For now I think I'll find get some driftwood to try and lower it slightly and look at some hard water fish.
Driftwood is a good and healthy addition for any tank and your corys will certainly appreciate it. I'm afraid its not going to touch your hardness or pH though. Your high KH will act as a buffer and whatever you add to the tank it will always bounce back to its original value. By all means add wood, but don't try to use any chemicals to adjust the pH. This would create a yoyo effect and probably result in dead fish.
 
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