Breeding Cardinal Tetras!

So, I have setup 2 tanks(actually storage boxes) for breeding Cardinal Tetra(and black neons). On another forum, someone who has bred cardinal tetras successfully suggested I breed them in rainwater.
However, I can't collect enough to put in my 15 gallon storage boxes.
So...
My tap water parameters:
pH: 7.2 -will be lowered accordingly
GH: 3- will also be lowered
KH: 1- Not necessary but will be lowered anyway.
So the parameters in the breeding tank are going to be:
pH: 6-6.5
GH 0-1-This is very important( the guy on the other forum had a )GH of 80 ppm, then the fry didn't hatch, they only hatched in 0 ppm)
KH 0-1
So I currently have 3 females full of eggs and 6 males. Separated them today - continuing for 5 days.
My storage boxes are black since the eggs are light sensitive, and I have a lot of floating plants.
this is what I did-and going to do
first 3 weeks - conditioned for breeding
Day 1(today): separated
Day 6: Add both males and females to storage box.
Day 7: Hopefully they have spawned- remove all adults.
Day 8: Nothing
Day 9: Nothing
Day 10: Feed egg yolk(pushed through fabric)
Day 11 - 25: Continue same food
Day 24: Start feeding baby brine shrimp or daphnia.
Day 25 and onwards: wait till they reach at least 2 months and sell them.

 

for breeding Cardinal Tetra

Been there, not done it in the end after I found out what you are going to find out now.

KH: 1- Not necessary but will be lowered anyway.

Has to be lowered, otherwise you won't get into the necessary pH- and conductivity-range.

pH: 6-6.5

Too high. The necessary pH would be 4.5 - 5!

The necessary parameters (proven over and over again):
GH/KH: 0°
pH: 4.5 - 5
TDS: under 20mg/l (= 20ppm)
EC: under 50µSI/cm

These parameters are ONLY achievable with pure rainwater, RO, DI or distilled water. Otherwise you will have to pretreat your water with chemicals (diluted hydrochloric acid) until KH is low enough to turn pH below 5.

And even then you need to be lucky. If the prospective parents were tankraised or have lived in tapwater during their youth they usually are invertile (One of the consequences of keeping softwater/blackwater fish in too hard water.).

So if possible get a group of wild caughts. Condition them with black mosquito larvae, daphnia and artemia. Keep them in a tank with low conductivity (100% RO), pH for conditioning can be around 5.5. - 6.

(and black neons).

A friend of mine managed to do this unintentionally this year, he has about a dozen almost adult fish out of that and they keep multiplying. The fry managed to survive in a blackwater tank with Cleithracara maronii, blackskirt tetras, adult black neons and Corydoras paleatus. They spawned in the big root ball of a Monstera plant he has growing out of the water.

Parameters:
GH/KH: 0°
pH: 6.0
TDS: 80mg/l
EC: 150µSI/cm

Good luck.

 

Been there, not done it in the end after I found out what you are going to find out now.


Has to be lowered, otherwise you won't get into the necessary pH- and conductivity-range.


Too high. The necessary pH would be 4.5 - 5!

The necessary parameters (proven over and over again):
GH/KH: 0°
pH: 4.5 - 5
TDS: under 20mg/l (= 20ppm)
EC: under 50µSI/cm

These parameters are ONLY achievable with pure rainwater, RO, DI or distilled water. Otherwise you will have to pretreat your water with chemicals (diluted hydrochloric acid) until KH is low enough to turn pH below 5.

And even then you need to be lucky. If the prospective parents were tankraised or have lived in tapwater during their youth they usually are invertile (One of the consequences of keeping softwater/blackwater fish in too hard water.).

So if possible get a group of wild caughts. Condition them with black mosquito larvae, daphnia and artemia. Keep them in a tank with low conductivity (100% RO), pH for conditioning can be around 5.5. - 6.


A friend of mine managed to do this unintentionally this year, he has about a dozen almost adult fish out of that and they keep multiplying. The fry managed to survive in a blackwater tank with Cleithracara maronii, blackskirt tetras, adult black neons and Corydoras paleatus. They spawned in the big root ball of a Monstera plant he has growing out of the water.

Parameters:
GH/KH: 0°
pH: 6.0
TDS: 80mg/l
EC: 150µSI/cm

Good luck.

I will try with tap water, if it doesn't work then I'll follow your advice. Thank you!

Ok I'm putting both male and female into the breeding tank today, with a layer of peat moss as flooring. I'm excited, but I may be setting myself up for failure.

 

Ok so I tried putting my peat moss in the black breeding box. Then it floated lol and it didn't go down. So I put a handful in the blue breeding box.
I caught my 6 male cardinals and my 3 females, and put them in a stainless steel bird food bowl(I used to have budgies). Then I floated them on the top of the water because the water was warm.
then I released them. they are doing ok. I have put hydrilla from a cycled tank in it.
So I'm waiting for the peat to sink.

 

You're impatient. Leave the tetras in their tank until the boxes are ready. It takes some days to get ready, the peat settled and the moss thoroughly soaked. Monitor the water parameters in the meanwhile. And remember the fish have to be acclimated to the extreme parameters in their holding tank.

 

You're impatient. Leave the tetras in their tank until the boxes are ready. It takes some days to get ready, the peat settled and the moss thoroughly soaked. Monitor the water parameters in the meanwhile. And remember the fish have to be acclimated to the extreme parameters in their holding tank.

I have to admit that I am. Ok I'll leave them in the QT. I'm making a DIY drip acclimation.

I have to admit that I am. Ok I'll leave them in the QT. I'm making a DIY drip acclimation.

So, as I said yesterday, I moved them to one storage box. But I don't want to move them to the QT coz they will get stressed so I'm not. I have added some peat to their current box, anyway I need it to be like that so I don't have to do a drip acclimation, also I am breeding black neons. 70% of the peat has sunk. So the parameters are...
Blue storage box(with tetras)
Ammonia: 0-0.1
Nitrite: 0
Nitrate: 5
pH: 7(from 7.2, I'm going to give it time)
GH: 2
KH: 0 (confirmed, yay I'm super super happy)
Haven't tested TDS or EC, will do so now.
Black storage box:
pH: 6.8
GH: 2
KH: 0
Not tested TDS or EC, will do now.

 

parameters were the same as yesterday.

 

You have to add more acidity. Preferrably with a bag of peat.

 

You have to add more acidity. Preferrably with a bag of peat.

Both tanks have a flooring of peat moss.

 

Which by now should have released all humic substances it contained. That's not enough. pH is a logarithmic scale. Meaning to get the pH down by 1,0 from 6 to 5 you need 10 times the amount of free H+ ions (that's what pH measures) than you need from 7 to 6.

 

Which by now should have released all humic substances it contained. That's not enough. pH is a logarithmic scale. Meaning to get the pH down by 1,0 from 6 to 5 you need 10 times the amount of free H+ ions (that's what pH measures) than you need from 7 to 6.

So... how much peat moss do I need?

 

If it's just peat moss and not actual peat you can forget it.
With actual peat (the brown stuff that almost looks like soil) it still depends on the quality. It's a nature product, you can't give a recipe for that. You'll have to experiment and see how much lowers the pH to a certain level. Start maybe with 200 grams of peat in a filter media bag per 50 liters of water, let it sit, test after 24h, test again after 48.

I told you before to be patient. This is not something you do in a week or two.

I would also advise you read up on water chemistry.

 

If it's just peat moss and not actual peat you can forget it.
With actual peat (the brown stuff that almost looks like soil) it still depends on the quality. It's a nature product, you can't give a recipe for that. You'll have to experiment and see how much lowers the pH to a certain level. Start maybe with 200 grams of peat in a filter media bag per 50 liters of water, let it sit, test after 24h, test again after 48.

I told you before to be patient. This is not something you do in a week or two.

I would also advise you read up on water chemistry.

Oh it's peat moss not peat! How silly I am. Would Sera super peat work? How much would it lower the pH by? I just read your blackwater thread. Ok I'll be patient.

 

Would Sera super peat work?

Yes. Peat pellets do work. Please use them according to instructions.

How much would it lower the pH by?

Can't say 100%, still a natural product so results may vary. With 0 KH water you should end up between 4 and 5 within 72 hours. Roughly. Maybe a bit above 5, maybe a bit below 4. Impossible to predict with accuracy, even with experience.

I just read your blackwater thread.

Good, hope that helps you understand that this is a marathon and not a sprint.

 

so I don't want to waste money on buying peat(it is quite expensive) when I can collect rainwater. There is a leak in my gutter at the back of the house where I can collect a full 8 gallon bucket of water every time it rains. My only concern is the water might get in contact with something that dissolves in the water and changes it's parameters. So I'm going to test the water next time I collect some.

 

Rainwater alone is almost completely void of KH and has a low pH (around 5-6 usually) at first, but you leave it standing for a while it will reach CO2/pH/KH-equilibrium with a too high pH for your project. You have to add acidity in some form and peat is still easiest.

 

Rainwater alone is almost completely void of KH and has a low pH (around 5-6 usually) at first, but you leave it standing for a while it will reach CO2/pH/KH-equilibrium with a too high pH for your project. You have to add acidity in some form and peat is still easiest.

On another forum, someone who successfully bred cardinals only used rainwater and succeeded, with hundreds of fry. So I'm going to test it, and see how long it takes to change.

 

Collected a full bucket of rainwater. Will now test.

 

Well now I know the water dripping off my gutter isn't pure because when I tested, the parameters were this...
pH: 7.4
GH: 2
KH: 2
so um, I'm trying with indian almond leaves. Just collected about 20.
My sister really likes my tanks and helped me with moving my frogbit to the breeding tanks.
She especially likes Candy the betta.

 

I repeat it a last time: If you have measurable KH, you won't get pH as far down as needed and it will stay in neutral territory.

You can't bend chemical and physical laws of nature.
Good luck trying.

 

I repeat it a last time: If you have measurable KH, you won't get pH as far down as needed and it will stay in neutral territory.

You can't bend chemical and physical laws of nature.
Good luck trying.

But the last time my KH became 0. So I think it will work.

 

pH - Wikipedia

Please read up on this and what it means that the pH-scale is logarithmic. You'll need a LOT of leaves and months of time with that method until you are where you want the parameters to be.

 

pH - Wikipedia

Please read up on this and what it means that the pH-scale is logarithmic. You'll need a LOT of leaves and months of time with that method until you are where you want the parameters to be.

Then I guess it's worthwhile collecting pure rainwater.

 

Good luck.

 

Ok so umm I think I'm not really ready to breed cardinals, because I don't even know where I'm going to put them and I'm actually 'hoping' I can get a buyer... so I don't want my fish to become egg bound so how do I get them to spawn?

 

Ok so I think I can do it if I find a buyer(I'm asking my lfs if they will take/buy fish) but I won't do it if I don't find a buyer beforehand.
so..
Could I use neon ph-down to reduce pH? I've made my own drip acclimation.
Using distilled water to reduce Gh
and IAL to reduce KH. so umm... think this will work?