Help what happened

KH of 161=9 DKh which aint bad.
Calcium looks good.

Did you strain off the clear kalk from the powdery stuff at the bottom?

 

Don't even bother testing untill everything settles. The test kit is reading the suspended particles now. Your alk will end up being very low when the tank clears up. You basically threw your chemistry out of balance and caused a precipitaion event. The carbonates that precipitated will not dissolve back into solution so you will have to dose to bring them back up.

I'll throw this in too, even tho I don't think anyone ever reads all these informative links I post.

What is that Precipitate in My Reef Aquarium?
"The following important points should help in dealing with a limewater overdose:

1. Don't panic! These overdoses do not usually cause a tank to crash.
2. The primary concern is pH. If the pH is 8.6 or lower, you need not do anything. If the pH is above 8.6, then reducing the pH is the priority. Direct addition of vinegar or soda water is a good way to accomplish this goal. Either one mL of distilled white vinegar, or six mL of soda water, per gallon of tank water will give an initial pH drop of about 0.3 pH units. Add either to a high flow area that is away from organisms (e.g., a sump).
3. Do not bother to measure calcium or alkalinity while the tank is cloudy. The solid calcium carbonate particles will dissolve in an alkalinity test, and all of the carbonate in them will be counted as if it were in solution and part of "alkalinity." The same may happen to some extent with calcium tests. Wait until the water clears, and at that point, alkalinity is more likely to be low than high. Calcium will likely be mostly unchanged.
4. The particles themselves will typically settle out and disappear from view over a period of 1-4 days. They do not appear to cause long term detrimental effects to tank organisms.
5. Water changes are not necessarily beneficial or needed in response to a limewater overdose."
​

 

Why are you dosing in the 1st place? Do you know how much alk/ca your tank is consuming daily? As you see, you can't just guess what you need or don't need to supplement.

 

But you did...and that was the kalk.
What Your Grandmother Never Told You About Lime

Here's another article to read if you think you are having low pH problems. BTW, what does your pH usually run?
Low pH: Causes and Cures