Are these fish ok for my tank

[CassCats]

For spawning purposes yes, but not full time living

 

[Fish4dawin]

Guys, my tank can hold 130cm ish of fish and it's currently at 180cm. Would I be able to get 5-6 more corydoras?

 

[mcordelia]

One way to tell how your tank is handling the bioload is to measure nitrates before your next water change. If there above 20ppm, then you need to consider whether you will be able to handle a consistent routine of more frequent water changes to keep up with the bioload in the tank.

 

[Fish4dawin]

One way to tell how your tank is handling the bioload is to measure nitrates before your next water change. If there above 20ppm, then you need to consider whether you will be able to handle a consistent routine of more frequent water changes to keep up with the bioload in the tank.

Ok, but do you think I could add around 25cm more of corydoras @mcordelia? @NCaquatics what do you think as well? I know if I am able to get corys then I will go with sterbai without a doubt. @essjay , do you think I could fit that amount of fish in? Currently there is 180 cm when the tank can hold 130cm?

 

[mcordelia]

I can't really answer your questions until you reflect on the points I made above. What are your nitrates before water changes? Are you able to commit to twice weekly large water changes if necessary?

Stocking depends on the following factors:
1) fish suitability to water
2) fish suitability with each other
3) existing bioload of tank (filtration, plants, water change routine, pH, etc)
4) owner ability to take care of any fish special considerations (typically applies to more complicated fish)

Over the course of this thread, you have progressed through researching items 1 and 2, so now you're at 3 where you have to figure out whether your particular tank can handle more fish. We can't really tell you that, because there are a lot of factors involved. The "inches per gallon" rule is a good rule of thumb to start with, and I would say for novice fishkeepers is probably not worth exceeding. However, there are many aspects that factor into whether water parameters are stable and healthy for the fish, including things like pH (if you have soft water and a low pH for example, your tank is potentially more at risk for generating poisonous conditions if ammonia spikes than a hard water high pH tank). Plants play a big role in stabilizing water parameters as well. Finally, it depends on you and your ability to commit time to your fish. I personally cannot do a water change every week because my schedule doesn't allow for that, so I have to take it into account when stocking my tank. If I understand correctly, you don't spend the full week where the fish tank resides, so that may make any complicated water change schedules infeasible for you. What about setting up another fish tank at the other house? Is that a possibility?

 

[Essjay]

In a tank with no live plants, nitrate should not go up by more than 20 ppm above tap water level. In a tank with live plants, nitrate will not increase by that much, if at all, even with an overstocked tank as the plants remove ammonia made by the fish and they don't turn it into nitrate.

if you have soft water and a low pH for example, your tank is potentially more at risk for generating poisonous conditions if ammonia spikes than a hard water high pH tank

It's the other way round

Ammonia in water exists in 2 forms - toxic ammonia and non-toxic ammonium. The amount in each form depends on the pH (and temperature but our tanks don't vary by more than the odd degree or two while pH can vary a lot).
The lower the pH, the more is ammonium and at very low pH there is virtually none in the toxic form. But as the pH increases above 7, the more there is in the toxic ammonia form.
Hardness itself doesn't affect the ammonia-ammonium balance, though high pH is more likely in hard water and low pH in soft water. (Though some places have pH over 7 with soft water - I live in one)

 

[Fish4dawin]

I can't really answer your questions until you reflect on the points I made above. What are your nitrates before water changes? Are you able to commit to twice weekly large water changes if necessary?

Stocking depends on the following factors:
1) fish suitability to water
2) fish suitability with each other
3) existing bioload of tank (filtration, plants, water change routine, pH, etc)
4) owner ability to take care of any fish special considerations (typically applies to more complicated fish)

Over the course of this thread, you have progressed through researching items 1 and 2, so now you're at 3 where you have to figure out whether your particular tank can handle more fish. We can't really tell you that, because there are a lot of factors involved. The "inches per gallon" rule is a good rule of thumb to start with, and I would say for novice fishkeepers is probably not worth exceeding. However, there are many aspects that factor into whether water parameters are stable and healthy for the fish, including things like pH (if you have soft water and a low pH for example, your tank is potentially more at risk for generating poisonous conditions if ammonia spikes than a hard water high pH tank). Plants play a big role in stabilizing water parameters as well. Finally, it depends on you and your ability to commit time to your fish. I personally cannot do a water change every week because my schedule doesn't allow for that, so I have to take it into account when stocking my tank. If I understand correctly, you don't spend the full week where the fish tank resides, so that may make any complicated water change schedules infeasible for you. What about setting up another fish tank at the other house? Is that a possibility?

I don't stay where the tank is all the time unfortunately, my dad will only want a small tank which won't be able to accomodate most of the fish. Maybe an ancistrus could go there but they get quite big. But, I probably won't get a tank where I am now, as my dad wants me to be able to look after my other ones first and then maybe look at another tank here. He did have one but he removed it unfortunately. And also there isn't much room

 

[mcordelia]

It's the other way round

Here I was thinking there was some redeeming factor to my awful water, but guess not! Sorry that I got it backwards, I must have misunderstood back when you and ITViking were talking about his fish-in cycle.

So I want to make sure I have this right: soft water with low pH is the "best" in terms of not being toxic immediately when ammonia starts to appear, or is there no bearing on hardness at all? Say if you had hard water with low pH (I know that's much more unusual die to the buffering capacity of most minerals that make up "hardness"), would your fish be equally not quite as screwed as in the soft water low pH scenario?


In general though, a softer water tank can "crash" faster than a hard water tank because it lacks the buffering capacity, right?

 

[Fish4dawin]

In a tank with no live plants, nitrate should not go up by more than 20 ppm above tap water level. In a tank with live plants, nitrate will not increase by that much, if at all, even with an overstocked tank as the plants remove ammonia made by the fish and they don't turn it into nitrate.




It's the other way round

Ammonia in water exists in 2 forms - toxic ammonia and non-toxic ammonium. The amount in each form depends on the pH (and temperature but our tanks don't vary by more than the odd degree or two while pH can vary a lot).
The lower the pH, the more is ammonium and at very low pH there is virtually none in the toxic form. But as the pH increases above 7, the more there is in the toxic ammonia form.
Hardness itself doesn't affect the ammonia-ammonium balance, though high pH is more likely in hard water and low pH in soft water. (Though some places have pH over 7 with soft water - I live in one)

With the plants I got some broad leaved ones and some curly ones. The curly ones are fine but my lemon ancistrus completely obliterated the broad leaved ones. I have been advised to go with anubias and java fern as they are hardier. Is this correct?Should I get some java fern and anubias to help remove ammonia?

 

[Essjay]

Java fern and anubias are reported to taste nasty to fish so they leave them alone. I can't say how true that is from personal experience as I don't have fish which are prone to eating plants.

Both java fern in it's different varieties (standard, windelov, trident, narrow leaf etc), and the several species of anubias are slow growing plants so they don't take up much ammonia compared to fast growing plants. The best are floating plants - the surfaces of both my tanks are covered with Amazon frogbit.

 

[Essjay]

So I want to make sure I have this right: soft water with low pH is the "best" in terms of not being toxic immediately when ammonia starts to appear, or is there no bearing on hardness at all? Say if you had hard water with low pH (I know that's much more unusual die to the buffering capacity of most minerals that make up "hardness"), would your fish be equally not quite as screwed as in the soft water low pH scenario?

Hardness does not affect toxicity at all.
Ammonia is less toxic at low pH and more toxic at high pH.
Nitrite is not affected by pH.
Nitrate is not affected by pH.

Hard water with low pH has the same lack of ammonia toxicity as soft water with low pH; similarly soft water with high pH is just as toxic as hard water with high pH. It's the pH that matters, whatever the hardness.


Ammonia is toxic, ammonium is non-toxic.

NH3 + H+ <-> NH4+
or
ammonia + hydrogen ions <-> ammonium ions


This is an equilibrium, or balance. In basic terms, the total amounts on both sides have to be the same.

pH is an upside down measure of hydrogen ions. In other words, the lower the number the more there are and the higher the number the less there are.
When the pH is low there are a lot of hydrogen ions. Adding H+ to the left of the equation pushes the equation to the right, towards ammonium, to keep the balance constant. The lower the pH, the more ammonium and the less ammonia there is.
As pH rises, there are fewer and fewer H+ so some of the ammonium loses an H+ to become ammonia to keep the balance level. At very high pH, there is a lot of ammonia, the toxic form.


Have a play with some numbers in this calculator https://www.hamzasreef.com/Contents/Calculators/FreeAmmonia.php
Set the salinity to zero (that's only used for marine tanks), enter a value for ammonia, say 0.5 ppm. Then enter a very low pH. Click 'calculate' and look at the number in the NH3 concentration box. Now increase the pH in stages and see how that number goes up.

 

[mcordelia]

ah, ok good old henderson-hasselbach and acid dissociation constants. always messed me up, will continue to mess me up

low pH -> lots of H+ -> drives equation right so predominant species is ammonium, neutralizing its toxicity. In higher pH situations (less H+), the predominant species is ammonia, which is toxic.

so bottom line: ammonia is toxic, ammonium is less toxic. If you have low enough pH, more of the ammonia will convert to ammonium, rendering it less lethal to fish. However, because it's an equilibrium constant, there will always be some ammonia present in its nonionized form, so it's not like low pH is the panacea.

Thanks @essjay

 

[Essjay]

You got it

At very low pH there is so little in the ammonia form that we can regard it as zero. And at just below pH 7.0, while there is some in the ammonia form, it is still a small amount and when the total ammonia (ammonia + ammonium, the way our test kits measure it) is small, say up to 0.5 reading with a tester, again there is so little ammonia that we can disregard it.
But at pH over 7, even with small amounts of total ammonia, there is enough ammonia to harm fish

 

[Fish4dawin]

@essjay how many tanks do you own? What inhabits them?

 

[Essjay]

I have just 2 tanks.
The 23 litre has red cherry shrimps and a nerite snail.
The 180 litre has pearl gouramis, espe's rasboras, kuhli loaches, chili rasboras (that were supposed to be in the 23 litre but were moved as they huddled at the back), the last few Daisy's rice fish, and the last few Boraras urophthamoides. And a few nerite snails and the shrimp I couldn't catch to move into the small tank.

I have had more tanks over the years, including a 54 litre tank which was in the kitchen but when we had that altered there was no longer any room for the tank so I had to close it