Calcium content in breeding tank

[e_abuzer]

Hello everyone,
I've read a lot about tds/gh/kh. I looked around in SD for Calcium content for breeding but couldn't find the answer. I know that the above three tests are important, and there's plenty of information on the reference values for those. But from what I've been reading, it seems to be the calcium content, rather than those other minerals and solids, that prevents fertilization and calcifies the eggs. So here goes:

What is the acceptable Calcium content range for a domestic discus breeding tank?

The reason for the question is that I've read people saying they breed their discus just fine in 8.2pH or 150ppm TDS. I guess the Calcium content in that TDS is what counts. It would certainly make life a lot easier if one could use tap water and not R/O. So although one has "Hard water" it may be that the calcium content is low. My pairs spawn just the same in 325ppm. If I had a reference value, maybe I could use less R/O. (Trying to save time&cash here )

Any reference would be much appreciated.

[LizStreithorst]

Calcium comes in many forms. It's calcium carbonate that inhibits eggs from hatching. Carbonate hardness is measured with a kH test. I know that everyone's water is different but the lower your kH the less RO you should need to use.

[CliffsDiscus]

What happen to the last batch, from the picture the eggs were very fertile.

Cliff

[e_abuzer]

What happen to the last batch, from the picture the eggs were very fertile.

Cliff

They all turned white. Didn't look calcified though. Probably fungus took over. Or maybe they weren't fertilized? Couldn't tell. Next time I will use 0.5ml of %37 formaldehyde for 100 litres . I don't have any meth blue except the one I got from a lab chemical store that says "meth blue that dissolves in alcohol " and I don't know what the concentration is, thus reluctant to use it.

[e_abuzer]

Calcium comes in many forms. It's calcium carbonate that inhibits eggs from hatching. Carbonate hardness is measured with a kH test. I know that everyone's water is different but the lower your kH the less RO you should need to use.

Thanks Liz,
I'm guessing preventing from hatching means getting fertilized in the first place? My kH is 2 dkh @ 110ppm of tds. Does this mean that 110ppm is fine for breeding? What is the safe range for carbonate hardness for breeding?

[e_abuzer]

BTW, I just noticed this:
For every 50ppm of tds my kH goes up by 1dkH. My tap water is 330ppm with 8pH. Aged and aerated it becomes 250ppm and 7.5 pH. (Not heated)

[LizStreithorst]

With a kH of 2 I'm surprised that you are having trouble. Still, water is weird. Why not give Cliff's method of hatching in a gallon pitcher full of pure RO. I'm dying for another spawn from one of my pairs so I can try it with Discus. It sure does work with Rams.

[CliffsDiscus]

Your eggs died during incubation period, this is very common. Take a look the eggs they are abnormal. Hopefully the next batch will be
better.

Cliff

[e_abuzer]

OK,
So I got the new batch after 10 days. Water is @75ppm tds, kH=2, ph=6.9. Added 1 drop 37% formaldehyde per gallon to see if they fungus again.
This is a picture of the spawn:
day1.jpg
This is day2:
day2.jpg

After this picture I noticed some missing eggs, so decided to fence the cone. After 62 hours, this is what I have:
day3.jpg

Thoughts/ ideas??? Maybe the male is infertile? I've seen him do the passes right after the female, but didn't get a chance to see the tubes. I'm pretty sure he's not a female because he wasn't laying any eggs during the passes.

[e_abuzer]

I got impatient and removed the fence @ 66 hours. I came back and half the eggs were gone. But there are 10 relocated wrigglers a little down the cone. I would love to hear your thoughts.

[LizStreithorst]

10 is usually not enough for the pair to want to bother raising. There are exceptions but in general the pair eat the kids when they free swim.

[CliffsDiscus]

I think your heater is too close to the eggs, that may be a problematic.

Cliff

[e_abuzer]

10 is usually not enough for the pair to want to bother raising. There are exceptions but in general the pair eat the kids when they free swim.

Yeah. I guess they will. Still good to know that the Male is not sterile. And the water is sort of OK, and the formaldehyde works. I don't know which works though, because I didn't isolate the variables

[e_abuzer]

I think your heater is too close to the eggs, that may be a problematic.

Cliff

That's a very good point Cliff. I guess it may be over heating that area while trying to heat the entire tank, causing extra fungal activity. I will move it. Thanks.