wrote:

I just bought a 25gallon aquarium about a week ago and put the substate
and live rock in it. I haven't put coral and fish in and today I
suddenly found the water turned yellow!

I have pumps (Rio 800) running and using Biological filter calls.. What
do you guys think the problem come from? I changed water (about 60%
change) today but still feel water is yellow. What do you think? Shall
I do a complete water change?

Thanks!


25 gal is small for a marine tank. Can be done, but it's trickier with
a small tank like that.

Yellow is from stuff decomposing on the live rock. This happens with new
live rock. it'll likely get a bit worse befpore it gets better.

Don't put any livestock in before this yellowing clears up. Don't fic it
by changing the water (not yet anyway) - you will screw up the cycling
if you start changing water thois soon.

You don't mention if you have a skimmer or not. Skimmers are NOT
optional, no matter what you may have heard or been told. You need one.
Get one. use it. It will pull a lot of the "yellow" out of your water.