to carbon or not to carbon???

[mouscacha]

I am in the process of upgrading to my 90. So I thought I should test my new 40 sump on my 20L. I found my water had a yellow tinge to it, but thought my new skimmer would do the trick. Well, I was wrong, and now I'm not sure what to do. Does this yellowing really have a negative effect on the tank? I hate to add another reactor to my already tight fit cabinet.

[Carlos]

Carbon will remove that yellowing, no problem.

Just add a small bag of carbon to a high-current part of the sump and that should do the trick.

Carlos