Crystal clear water goes yellow after carbon added!!!

[MissMolly]

Hi!

just cleaned my HOB Seachem Tidal filter today. Added new sponge but reused of course my Seachem Matrix. I haven't run carbon before but thought it wouldn't hurt so I added a bag of Fluval activated carbon media.

My water was crystal clear before and now it's turning more and more yellow. What the heck?

All paramenters are fine. I haven't changed anything else but added the carbon and new sponge (new sponge was cut from the usual piece of big sponge that I have used many times now).

Hope you can help!

 

[Troylee]

Did you rinse the carbon?

 

[MissMolly]

Yes I rinsed it. It was very dusty... the water has even turned more yellow now. Doing a big water change now and taking out the carbon bag.