Is it too late to lower TDS?

[RogueDiscus]

Just causing trouble here, but interested in opinions. I've got eggs from a GF Cross pair that have been in 110 ppm water for 2 days, and they still have that nice dark center, not turning white. I would usually have the tds at 70 or less, but they caught me off guard and my RO was going elsewhere. If they're going to hatch I would expect it within a day. Do you think lowering the tds at this point would make a difference?

If I've got the water I might try, but wondering what the experiece was out there.

Steve

[Keith Perkins]

Absolutely not. TDS has an affect at time of fertilization, after that it's pretty much irrelevant. I go to straight tap within a day or two or the act and never look back.

[LizStreithorst]

I doubt that it will make much difference at this point, but it you want to try, why not?

[RogueDiscus]

Absolutely not. TDS has an affect at time of fertilization, after that it's pretty much irrelevant. I go to straight tap within a day or two or the act and never look back.

OK.
I'd be interested in a more in-depth explanation why at fertilization. I was thinking the higher calcium level caused the eggs to "harden" later and the fry not being able to break out.

So, they look fertile. The hardness won't affect their hatching?

[Keith Perkins]

Harder water can make fertilization of the eggs more difficult, not the break out later. You've got the right idea, just a little too late in the process.

No, the hardness now won't affect their hatching. If they look fertile at this point you should be in good shape.

[nc0gnet0]

Absolutely not. TDS has an affect at time of fertilization, after that it's pretty much irrelevant. I go to straight tap within a day or two or the act and never look back.

Hmmm.. this is not my experience.

to the OP, it won't hurt a thing, so why not?

[Keith Perkins]

Hmmm.. this is not my experience.

Well that's interesting. You've certainly got a larger test population.

[nc0gnet0]

Well that's interesting. You've certainly got a larger test population.

I understand that is the common perception, but I have on several occasions pulled a fresh spawn of eggs out of high tds water (from a pair that spawned in a community tank), placed them into a breeding tank with another pair (in low tds water) and had them hatch.

If I leave the same batch of eggs (or another batch from the same pair the following week) in the same high TDS water, they all go white and I get zero hatch. At least in my water, it seems to cast a shadow of doubt on the "high tds prevents fertilization" theory.

My counter "theory" (and I am not saying this is fact) is that while the eggs do get fertilized in high tds water, they calcify and the embryo suffocates when left in high tds water. Or, maybe it is a combination of the two, I am not really sure, just sharing what I have witnessed. Al and myself have had a few conversations on the matter.

-Rick

[rickztahone]

I understand that is the common perception, but I have on several occasions pulled a fresh spawn of eggs out of high tds water (from a pair that spawned in a community tank), placed them into a breeding tank with another pair (in low tds water) and had them hatch.

If I leave the same batch of eggs (or another batch from the same pair the following week) in the same high TDS water, they all go white and I get zero hatch. At least in my water, it seems to cast a shadow of doubt on the "high tds prevents fertilization" theory.

My counter "theory" (and I am not saying this is fact) is that while the eggs do get fertilized in high tds water, they calcify and the embryo suffocates when left in high tds water. Or, maybe it is a combination of the two, I am not really sure, just sharing what I have witnessed. Al and myself have had a few conversations on the matter.

-Rick

cool observations Rick. Thanks for sharing them. Is it the breaking out part that they would struggle with at higher TDS?

[nc0gnet0]

cool observations Rick. Thanks for sharing them. Is it the breaking out part that they would struggle with at higher TDS?

Not quite sure what your asking here Rick, and just to let you know, me and Al kinda disagree on my theory.........

[RogueDiscus]

Well, they're gone this morning. Next time!

[rickztahone]

Not quite sure what your asking here Rick, and just to let you know, me and Al kinda disagree on my theory.........

What I mean is, at the wigglers stage, they have to break out of the "sack" correct? If, the TDS is higher, I am guessing that the "sack" is tougher to break through and this would cause the suffocation? However, with your experiment, it may just be that when in higher TDS water, the "sacks" haven't had enough time to harden enough to suffocate them at that stage. Hence, when you place them in lower TDS water, they can still hatch.

I may just be talking non-sense now, but just trying to get a better understanding of the concept. When it comes to breeding, I am a complete n00b

[LizStreithorst]

For whatever it's worth I've taken Angel eggs laid in hard water and moved them to RO and they hatched every time. I agree with Rick on this one.

[rickztahone]

For whatever it's worth I've taken Angel eggs laid in hard water and moved them to RO and they hatched every time. I agree with Rick on this one.

are discus eggs and angel eggs very similar? How about brood sizing?

[LizStreithorst]

Discus and Angels are very similar. Their eggs require the same water parameters to hatch. I was told on My Angel forum that eggs formed and laid in hard water wouldn't hatch if moved to soft water but the people who told me that were just repeating what they'd heard. Their eggs hatch in straight tap so they didn't know from experience. I know from experience.

[delta5]

Maybe it is also worth mentioning you should assume everyone has different tap water.

[RogueDiscus]

I'm on a well. My tds are about 450 ppm. I haven't had it tested (keep meaning to do that, just lazy) but I can tell from the sediment filter that it has iron in it. I use a bit of Prime with my well water, even though I have no chlorine, to deal with heavy metals and whatever. I mix with RO to keep my community and grow-out tanks at about 200 ppm. I go to 60 or lower on my breeders.

[LizStreithorst]

Iron is a *****. I switched to community water because my well water was so full of iron.

[CliffsDiscus]

Maybe it is also worth mentioning you should assume everyone has different tap water.

Exactly, my water is already soft but I stilll use pure RO for hatching, this probably will only give me around a 10 percent hatch rate increase.
Another thing even with the pure RO the fry can't hatch out of the shell simply because they are too weak.