How does a minor WC have such drastic effect on corals?

[pomoev]

Hi,

I recently skipped a couple weeks of water changes and noticed some of the corals (most noticeably neon candy cane) stopped fully opening, and showed even some minor tissue recession. I changed about 10% of water and the next day all the corals were looking great as they should.
My question is, what exactly got fixed by that minor water change? I don't believe that a 10% concentration change in any major element would have such a drastic effect on corals. More plausible sounds the idea that something with minor presence (but still required) dropped to zero, and after the water change it raised back to above zero levels. Trace elements come to mind. Can zero level of iodine or say potassium affect the state of corals so much that they stop looking healthy?

I only dose kalk with a kalk stirrer.

Params:
Alk - 9,
Ca - 450,
Phosphates - <0.1,
Nitrates - 8-10.

 

[sfin52]

Hi,

I recently skipped a couple weeks of water changes and noticed some of the corals (most noticeably neon candy cane) stopped fully opening, and showed even some minor tissue recession. I changed about 10% of water and the next day all the corals were looking great as they should.
My question is, what exactly got fixed by that minor water change? I don't believe that a 10% concentration change in any major element would have such a drastic effect on corals. More plausible sounds the idea that something with minor presence (but still required) dropped to zero, and after the water change it raised back to above zero levels. Trace elements come to mind. Can zero level of iodine or say potassium affect the state of corals so much that they stop looking healthy?

I only dose kalk with a kalk stirrer.

Params:
Alk - 9,
Ca - 450,
Phosphates - <0.1,
Nitrates - 8-10.

Minor and trace elements

 

[Arego]

^ that

 

[nereefpat]

More plausible sounds the idea that something with minor presence (but still required) dropped to zero, and after the water change it raised back to above zero levels. Trace elements come to mind.

I think you're right.

I would generally recommend changing water at least 5% or so a week. And if you don't, then I would argue for ICP testing.

 

[sfin52]

Trace elements come to mind. Can zero level of iodine or say potassium affect the state of corals so much that they stop looking healthy?

Absolutely

 

[Arego]

Looking at a coral wrong can make it unhappy, definitely don't underestimate the importance of adding back what the corals took out to look good and grow. Whether by water change or additive.

 

[pomoev]

Thank you everyone for your answers.