Almost Killed two coral

[celebrity2be]

I did a water change last night, put in PH buffer (first water change since getting coral) and two of my smaller corals shrank and got a translucent/white film around them. How did that happen? Did i almost kill them? I only did a 10% water change.
Thanks,
Jim

[Sugar Magnolia]

Did you test your pH before adding the buffer? You may have spiked your pH which would have stressed your coral. What kind of corals do you have?

[celebrity2be]

I did not test my ph - i should have, but that was just the routine i was used to. I have mushrooms blue and red, leather tree, and purple polyp.

[michellejy]

The general rule is don't dose unless you are testing.

Also, did you dose directly into the tank, or did you put the buffer in the water change water?

[celebrity2be]

Directly in the tank :( - Can you tell how much i really dont know about this hobby? lol

[michellejy]

We all screw up :)

You have pretty hardy corals, so I doubt you did any permanent damage. (As an example, I was moving a mushroom frag to a different rock in my tank and ended up dropping it underneath the large rock at the bottom of my tank. There was no way I could get it out without pulling every piece of live rock out of my tank, and it just wasn't worth it to me. About a month later, I saw some red where there wasn't any before. It turns out my mushroom had worked its way out of a crevice in the rock pile and has multiplied several times. Like I said, we all screw up. :lol: )

So going forward, test your PH since there is a good chance you don't actually need the buffer at all. If you do, mix it in the water change water first and then add it to the tank.